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The GPlates User Manual

1. Next Create and Save After creating your flowline feature you should see the reconstructed flowline s on the globe or map Flowlines will automatically reconstruct appropriately for the current reconstruction time File Edit View Reconstruction Layers Tools Palaeomagnetism Help Q Lat 2 X t i B 7 d q Feature Create Feature S lat 41 71 lon 136 70 Featuretype PlateID Name Clicked geometry Begin End Created Present day geometry lat 13 3 Saving flowlines Flowline feature collections can be saved in gpml format and loaded like other feature collections 13 4 Editing flowlines Flowline features can be edited like other features by selecting Choose Feature from the Tool Palette and clicking on the central seed point of the flowline 13 5 Exporting flowlines Reconstructed flowline geometries can be exported to GMT and ESRI Shapefile format To export flowlines select Export from the Reconstruction menu After selecting Add you can select Flowlines as the export data type Reconstructed Geometries Projected Geometries Colat lon Mesh Velocities Resolved Topologies Relative Total Rotation Equivalent Total Rotation Equivalent Stage Rotation Raster Flowlines Motion Paths Export flowlines Format GMT xy Shapefiles shp When exporting to GMT format each reconstructed flowline point is output in the form lo
2. J There will still be small gaps of varying size if there are differences in the rotation model used to generate the age grid offline and the rotation model used to reconstruct the static polygons Currently the resolution displayed on screen is the lowest of the source raster and the age grid raster This means if you have an age grid that is lower resolution than your source raster then your source raster will never be displayed at its highest resolution no matter how much you zoom into the view However when no age grid raster is used the full resolution of the source raster is available The highest resolution of both source raster and age grid raster will be available in the next release 6 6 4 Age Grid Layer This layer is purely used to assist the reconstruction of a raster ina Reconstructed Raster layer Age Grid Options An Age Grid layer has the following configuration options agegrid_6m Age Grid Input channels Age grid feature agegrid 6m gpml Py COF ectror Add new connection Advanced options Disable layer There is no visibility icon because there is no visible output from this layer it is only useful as an input to a Reconstructed Raster layer The Input channels section has one type of input e Age grid feature is zero or one raster feature where each pixel is a floating point value representing the age of present day oceanic crust Also this raster must have been imported into GPlates
3. The table in the centre lists all the properties belonging to the currently chosen feature The left hand column lists property names and the right hand column lists property values The name of a property is a way to associate meaning with the feature data for instance this feature has a plate ID associated with it That plate ID is 308 It is stored in the gpml reconstructionPlateId property indicating that GPlates should use that plate ID to reconstruct the feature Clicking a row of the table will expand the bottom half of the dialog with new controls specific to the property that was clicked 9 2 5 Editing Geometry For further information on editing feature geometries please read the Editing Geometries chapter The controls for directly editing the coordinates used by geometry appears as a table with Lat Lon and Actions columns Click a row ofthe table to select it and the following action buttons will appear T Insert a new row above v Insert a new row below Delete row e Double clicking an entry in the table lets you edit a coordinate directly o The Valid Geometry line will indicate if the coordinates in the table can be turned into correct geometry It will indicate an error if there is something invalid about the coordinates such as a lat lon of 500 or similar e The Append Points spin boxes are designed to be a convenient means of data entry if you need to enter some points from a hard copy source o C
4. Export reconstructed geometries Format Shapefiles shp Filename reconstructed_ u_ 0 2f xy n the number index 1 of the frame will lie in the inclusive range 1 N and will be padded to the width of the decimal integer representation of N u the index of the frame will lie in the inclusive range 0 N 1 and will be padded to the width of the decimal integer representation of N 1 f the reconstruction time instant of the frame in printf style f format d the reconstruction time instant of the frame rounded to the closest integer in printf style d format Cancel of OK 8 3 1 Select data to export Users can select an entry in this list and then the available output format will be listed in Format list 8 3 2 Format Select output file format in this list 8 3 3 File name template Specify the file name template which will be used to generate output file names 8 4 Export Items Below is a table of available export items tem roma O pesonpon Reconstructed Geometries GMT Shapefile Export the reconstructed geometries in their paleo coordinates SVG Projected Geometries Export projected geometries data according to the current View settings Colat lon Mesh Velocities gpml Export Plate velocity data You will need to have plate topologies and a mesh cap configured Resolved Topologies GMT Export resolved topologies as static po
5. A series of lines drawn end to end forming a closed shape It is assumed that the lines are non intersecting 11 2 Geometry Editing Tools The geometry editing tools are Canvas Tools and can be found in the Tool Palette To begin editing geometries it is first necessary to either e Select a feature using the Choose Feature Tool R or e Have started digitising some geometry using one of the three digitisation tools Polyline Multipoint Polygon S The Split Feature Tool P works only on a feature selected with the Choose Feature Tool Each geometry editing tool is only enabled if there s enough geometry for it to make sense to use that tool For example if you are digitising a polygon and have digitised three points so far then the Delete Vertex tool will be disabled because it doesn t make sense to have a two vertex polygon polygons require three or more vertices gt 11 2 1 g Move Vertex Tool Once you have selected a feature its properties will appear in the Current Feature Panel Little dots will appear on the chosen feature geometry representing the vertices and can be positioned to a new location The changes made to the geometry are immediate and there is no need to press an Apply button This tool is useful for correcting mistakes in the features geometry e 11 2 2 q Insert Vertex Tool If the current geometry is a polyline or polygon when the user clicks on a line a new vertex is inserted at t
6. Description DESCR Cancel Loading Reset Fields This dialog allows the user to select which shapefile attribute fields will be associated with GPlates feature properties The feature properties are listed on the left hand side of the dialog Alongside each feature property is a drop down box showing the name of the shapefile attribute field which will be associated with the feature property You can use the drop down boxes to change the shapefile attribute fields which you want to associate with each feature property B Map Shapefile Attributes Associate shapefile attributes with GPlates model properties Filename WorldO shp Model property Plate ID PLATEID1 lt none gt Feature Type REGION REFNO STRNO DESCR End PLATEID1 TOAGE Description TYPE TYPENO Cancel Loading Reset Fields By default GPlates will look for certain shapefile attribute field names and will initialise the drop down boxes with the following values Feature property Default attribute field name Begin PlateID PLATEID Feature type TYPE Begin FROMAGE End TOAGE If the default field name for a feature property cannot be found in the shapefile the drop down box will be initialised with lt none gt Once you have selected the mapping you want clicking OK will load the shapefile 15 2 2 Recording the mapping Once a mapping has been selected GPlates records this information on disk If the shapefi
7. The GPlates User Manual James Boyden John Cannon James Clark Rhi McKeon Mark Turner Robin Watson December 2010 GPlates User Manual Table of Contents 1 Introduction to GPlates 1 1 The Aim of this Manual 1 2 Introducing GPlates 1 3 GPlates Development 1 4 Further Information 21 The Main Window 2 2 Reconstruction View 2 3 The Menu Bar f oal Palette 3 1 faired iction a 2 Rastersi in GPlates 5 1 VEW Menu 5 2 Reconstruction View 2 2 Too Palette 6 Pe 6 1 Introduction T Becan 7 1 Introduction 7 3 Reconstruction Menu 7 4 Animations 92 eee L lntaracting u 10 More on ee 13 Flowlines E 13 1 Introduction 13 2 a flowlines l 151 a re eA ie 2 Shapefile attributes 16 1 ner 16 2 Topology Controls and Displays 1 Introduction to GPlates 1 1 The Aim of this Manual The GPlates user manual aims to provide the reader with an almost complete understanding of the operations applications and manipulations within GPlates software The manual is divided into chapters based on function and tasks For example a step by step guide to loading data into GPlates can be found in Loading and Saving an overview of editing the geometries of features can be found in Editing Geometries 1 2 Introducing GPlates GPlates is desktop software for the interactive visualisation of plate tectonics GPlates offers a novel combination of interact
8. This chapter covers the layers system how they are created what they do how they are visualised and the various types of layers 6 2 Layers in GPlates Layers provide a way to connect the various processing capabilities of GPlates to data sources such as loaded feature collections The outputs of these layers can then be visualised directly in the globe and map views and or passed to the input of other layers for further processing 6 3 What s the difference between a layer and a file A file contains a collection of features a feature collection A layer processes one or more inputs into an output Inputs to a ayer can include but are not necessarily restricted to feature collections For example some types of layers such as the Reconstructed Geometries layer accept both feature collections and the output of another ayer In the case of the Reconstructed Geometries layer e the feature collection input contains in the feature properties themselves both the geometries to be reconstructed and the information on how to reconstruct them such as reconstruction plate ID e the ayer input in this case the output of a Reconstruction Tree layer contains the rotations needed to perform the reconstruction e the layer itself does the actual reconstruction and generates the reconstructed geometries and e the ayer output contains the reconstructed features The reason the rotations come from the output of another ayer rathe
9. e Reconstructable features is one or more feature collections containing reconstructable features These are features that have geometry and have properties that provide enough information aside from a rotation hierarchy for GPlates to be able to reconstruct their geometry such as a reconstruction plate ID e Reconstruction tree is zero or one Reconstruction Tree layer This input layer provides the rotation hierarchy that enables GPlates to reconstruct the features in the Reconstructable features input channel If there is no Reconstruction Tree layer connected then the default Reconstruction Tree layer is used see the section on Reconstruction Tree Layer for more details on the default Reconstruction Tree The following is an example of an implicit connection to the default Reconstruction Tree layer because there is no explicit connection Reconstruction tree Add new connection 1f you then changed which layer was the default Reconstruction Tree layer then the new default would be implicitly connected This is useful if you have a lot of Reconstructed Geometries layers open and you want to change the Reconstruction Tree layer that they all use without having to reconnect each layer individually In this case you would just need to change the default Reconstruction Tree layer On the other hand if you explicitly connect a Reconstruction Tree layer then the default is ignored until you explicitly disconnect it Reconstruction
10. First use the Choose Feature Tool to select an existing topology You may have to click on the panel below to select the topology rather than the selected line Next click on the Edit Topology tool button 16 6 2 Editing the Topology Notice that the topology will be drawn with the highlighting described above The feature s basic data is placed into the Topology tab of the Task Panel and the Topology Sections Table will be filled with the list of boundary features From this point on the same basic editing steps described above such as inserting or deleting a line may be used to change the Topology Sections Table the boundary list Once you are satisfied with the changes click on the Apply Create button and the Topology s boundary list will be changed to the current contents of the Topology Section Table More advanced editing may be required with time dependent topologies Due to the semi automated nature of closing topologies a likely source of any problems that may arise is the constituting lines namely the length and or time of appearance and order of inclusion in the topology If not closed properly the polygon will fail and exhibit anomalous vertices and skewed lines A handy way of checking what a final polygon looks like is by turning off the lines This is achieved by clicking the Layers toolbar and unticking the Show line features option It may be necessary to break the time period of an existing topology for instance
11. Manage Feature Collections Sele Manage the feature collections which are loaded in the application File Name File Format Actions tng dale 1 DNSCO8GRA_6m gpml plane Za A tne Bag 2 agegrid_6m gpml PEE i Za A 3 Global_EarthByte_GPlates_Rotation_20100927 rot PLATES4 rotation 2 H Z E language YSAIA 4 Global_EarthByte_GPlates_PresentDay_StaticPlatePolygons_2010 TEREE i Z A Open File Save All Close will result in these layers being automatically created in this case one layer per feature collection cies tb Global_EarthByte_GPlates_PresentDay_StaticPlatePolygons_20100927 Reconstructed Geometries Global_EarthByte_GPlates_Rotation_20100927 Default Reconstruction Tree agegrid_6m Age Grid DNSCO8GRA_6m Reconstructed Raster J The layer name is obtained from the feature collection filename E Unloading a feature collection through the Manage Feature Collections dialog will also remove the corresponding layer or layers that were automatically created for it In some situations loading one feature collection can create two layers Here one feature collection containing both Topological Closed Plate Polygon features and the regular features referenced by them is loaded iD Manage Feature Collections SEE Manage the feature collections which are loaded in the application File Name File Format Actions aoe a S 1 Caltech_Global_20101129 gpml paca KR Za A Open File S
12. import a raster image into GPlates A global raster image is imported using the operation Import Raster in the GPlates File Menu This will show a dialog requesting the user to choose the raster image file to be loaded import Raster 4 lt jclark projects gplates data nasa Location world topo bathy 200407 3x5400x2700 jpg Places Name v Size Modified Q Search gebco_bathy 5400x2700 jpg 924 1KB 08 08 08 Recently Used s gebco_bathy 21601x10801 jpg 5 9MB 08 08 08 jclark ma land_surface_temperature 3600x1800 jpeg 1 3 MB 10 09 09 E Desktop net_radiation 3600x1800 jpeg 121 4 KB 10 09 09 El File System zm sea_surface_temperature colour 3600x1800 jpeg 1 7 MB 10 09 09 a sea_surface_temperature greyscale 3600x1800 jpeg 1 0 MB 10 09 09 S sea_surface_temperature_anomaly colour 3600x1800 301 3 KB 10 09 09 I Documents W Music ga Pictures s sea_surface temperature_anomaly greyscale 3600x1 185 1 KB 10 09 09 B Adni wa vegetation 3600x1800 jpeg 1021 8 KB 10 09 09 i Downloads E world 200401 3x21600x10800 jpg 20 8 MB 08 08 08 gplates world topo bathy 200407 3x21600x10800 jpg 24 7 MB 08 08 08 ka Ie Remove All rasters v cancel E Open If the selected raster image has been previously imported and hence has an associated GPML file then a message pops up giving you a choice to e use the existing GPML effectively cancelling the import process and instead loadi
13. 0 ea ze nena rte 00 250 henna rte 00a a poemate tomate 00208 Indeterminate Indeterminate 0 0 54 8892 146 569 15 1008 10 3 2 Equivalent Rotations Relative To Anchored Plate Similar to the Relative Rotations table this lists rotations for each plate However the data presented here has been converted from individual relative rotations into the equivalent absolute rotation relative to the anchored plate ID Again these apply to the current reconstruction time oel aaar Als Total reconstruction poles generated at Ma with anchored plate ID fo Relative Rotations Equivalent Rotations rel Anchored Plate Reconstruction Tree Plate Circuits to Anchored Plate Each equivalent rotation describes the motion of a plate relative to the currently anchored plate ID Piste _tattude tongtude Angle mowr fosi rar pow fose parr w pe peer osa aren 299 78 6497 301 302 303 25 1452 25 1452 25 1452 10 3 3 Reconstruction Tree Here the reconstruction hierarchy is presented in a more natural tree like form Relative rotations are listed but individual nodes of the tree plate IDs can be expanded or collapsed to explore the branches of the plate rotation model J tal ReconstrucHon Poles Total reconstruction poles generated at Ma with anchored plate ID fo Relative Rotations Equivalent Rotations rel Anchored Plate Reconstruction Tree Plate Circuits to Anchored Plate A tree lik
14. 5 92 dynto 92 jpg 1 laze 93 dynto 93 jpg i Z 94 dynto 94 jpg 1 95 dynto 95 jpg 1 86 dynto 96 jpg 1 97 dynto 97 jpg 1 98 dynto 98 jpg 1 99 dynto 99 jpg 1 100 dynto 100 jpg 1 Next gt Cancel A time dependent raster set is treated the same as a regular raster image by GPlates in the sense that when a new raster image or time dependent raster set is loaded it will create a single layer The same georeferencing and raster band options apply to time dependent rasters as they do to single rasters Although the age raster band name is only treated specially as an age grid that can assist with reconstruction of another raster for a single raster not time dependent A time dependent raster set can be reconstructed just as a single non time dependent raster can In this case the raster will be cutout into pieces according to static polygons which move independently across the globe just like a single raster but the image itself that s projected onto those pieces will change over time as defined by the time dependent sequence of images Links to existing time dependent raster sets may be found on the Downloads page of the GPlates website http www gplates org downloads html 3 3 3 How can I create my own time dependent raster set As already described a time dependent raster set is actually a sequence of raster image files contained within a single folder The name of the fol
15. Feature Collections dialog To specify a different file format change the file name extension e g dat pla etc to the extension for the desired format 4 2 How to Load a File There are several ways to load a data file or collection of files into GPlates 4 2 1 The Open Feature Collection menu item 1 Go to the File Menu in the menu bar 2 Scroll down to Open Feature Collection shortcut ctr1 0 3 A classic File Open dialog window will appear select the file to be loaded Open Files ZA lt i clark projects gplates data screenshotting Location PresentDay_Isochrons_20091015 gpm places A Name v Size Modified Q Search E Coastlines_20091014 gpml 23 0 MB 04 05 10 amp Recently Used PresentDay_COBs_20100414 gpml 355 9 KB 04 05 10 IB jclark E Desktop PresentDay_Ridges_20091015 gpml 729 8 KB 04 05 10 E File System Rotation_20091015 rot 166 4 KB 04 05 10 E Documents W Music i Pictures IE Videos E Downloads lE projects gplates uf oo o E Remove All loadable files Vv cancel jug Open You can open multiple files at once via this dialog Hold down ctr1 to select additional files then click Open 4 2 2 Drag and Drop 1 Open your file browser to the directory containing the files you want to load 2 Select the files you are interested in Multiple selection is usually possible by dragging a rectangle around files or holding ct r1 while click
16. How do I make one layer draw on top of another Layers are drawn onto the globe and map views in the order in which they are displayed in the Layers dialog Layers at the top are drawn on top of layers below them To change the visual ordering of a layer simply drag it onto another layer Either the unexpanded part of the layer the part containing the layer name and type or the coloured bar on the left expanded or unexpanded can be grabbed in this way You can still grab a layer when it is expanded you just need to grab in those areas of the layer Typically the mouse cursor changes to a hand grab icon over areas that allow layer dragging Global_EarthByte_GPlates_Rotation_20100927 Reconstruction Tree Global_EarthByte_GPlates_PresentDay_Ridges_20100927 Reconstructed Geometries Global_EarthByte_GPlates_PresentDay_Isochrons_20100927 Reconstructed Geometries Global_EarthByte_GPlates_PresentDay_StaticPlatePolygons_20101209 Reconstructed Geometries Global_EarthByte_GPlates PresentDay_COBs 20101209 Reconstructed Geometries Global_EarthByte_GPlates_Coastlines_20101209 Reconstructed Geometries Caltech_Global_20101129 Default Reconstruction Tree Caltech_Global_20101129 Reconstructed Geometries Caltech_Global_20101129 Resolved Topological Closed Plate Boundaries 129 mesh 10 Calculated Velocity Fields 129 mesh 10 Reconstructed Geometries agegrid_6m Age Grid DNSCO8GRA_6m Reconstructed Raster color_etop
17. Mesh Caps The Generate Mesh Caps dialog can be accessed via Reconstruction Generate Mesh Caps The mesh caps are used to calculate velocities The sphere will be covered by 12 diamonds Mesh Caps Each diamond will be further divided into smaller pieces according to Resolution setting Eventually the sphere will be divided into evenly distributed diamonds with equal area Resolution Users can specify the resolution of mesh caps The nodex and nodey parameters indicate how the 12 original big diamonds can be divided evenly For the global mesh the nodex always equals nodey Currently GPlates can only generate global mesh Output User can specify the file name template which will be used to generate output file names The Output directory indicates the directory where the output file will be stored In total 12 files will be generated in the specified output directory The file names are created from template for example d mesh c where the d represents the mesh resolution and c represents the cap index number A The d and c must appear in the template once and only once 7 4 Animations The animation dialog found in the Reconstruction menu allows you to automate a reconstruction backwards or forwards through time The user can set the start and end times by either entering the age or using the current time displayed in the main window The options frames per second can be set and there is also the option to loop the
18. Point of the Topology Section Table will be highlighted visually on the globe with slightly different coloring of the features on either side of it The feature before the insertion point will be drawn in Black and the feature after the insertion point will be drawn in White The mnemonic before black after white is a quick way to recall where a new feature will be inserted into the topology sections Table These visual cues may be helpful when fine tuning how various features particularly features with complicated polylines intersect to form a topology s boundary The vertices of each feature in the topological sections table will be used in a the reverse order if necessary haa from which they appear in the source feature s data This decision is performed automatically by GPlates for each feature in the sections table and requires no user involvement It ensures the final closed polygon will be created as a continuous closed polygon regardless of the orientation of each topological section Until all topological sections for a closed polygon are added the topological closed polygon displayed can look wrong The following shows what the topological polygon looks like when only two out of four topological sections have been added However once all topological sections are added and the topological polygon is closed the final closed polygon will be correct Note that the topological polygon is closed when all added topological sect
19. The types of input channel are specific to each layer type and will be covered in greater detail in the Types of layers section Input connections can be e added using the Add new connection option and e removed using the symbol to the right of each existing connection 6 4 3 Enabling and disabling a layer In the Advanced options section of each layer you can Enable and Disable the layer fe When a layer is disabled it is greyed out in the Layers dialog and cannot be changed until it is enabled again The Enable layer and Disable layer options determine if a layer does any processing or not If a layer is disabled then that layer is effectively switched off and nothing is generated or output by that layer It also means nothing will be drawn in the globe and map views for that layer regardless of that layer s visibility And it means any other layer receiving input from that layer will receive nothing then feature geometries are still reconstructed internally by GPlates for that layer they are just not displayed This is useful if you want the output of a Reconstructed Geometries layer to feed into the input of another layer but you don t want the reconstructed geometries to be visible Currently there aren t any good examples of when you might want to do this but there will be in the near future For example if the visibility of a Reconstructed Geometries layer is turned off but the layer is still enabled 6 4 4
20. a feature collection filename because it is not automatically created when a feature collection 1s loaded The new layer s input channels are all unconnected and you will need to make the connections explicitly in Phe order for the layer to function correctly It is OK to leave a layer in an unconnected state it will then simply do nothing 6 6 Types of layers There are various types of layers each represented by a different colour in the Layers dialog Each layer provides a different type of functionality has different types of inputs and generates different outputs 6 6 1 Reconstruction Tree Layer This layer combines rotation features from one or more feature collections to form a reconstruction tree or rotation hierarchy see the More on Reconstructions chapter for more information about rotation hierarchies This rotation hierarchy can then determine the equivalent absolute rotation of a plate relative to the top of the hierarchy the anchored plate Reconstruction Tree Options A Reconstruction Tree layer has the following configuration options Global_EarthByte_GPlates_Rotation_20100927 Default Reconstruction Tree Input channels Reconstruction features Global_EarthByte_GPlates_Rotation_20100927 rot Add new connection Reconstruction tree options View Total Reconstruction Poles Advanced options Disable layer Set as default reconstruction tree Since this type of layer does not produce visible ge
21. a Reconstruction Tree input have an explicit user connection then the default Fere Reconstruction Tree layer effectively does not apply However as soon as the user disconnects a Reconstruction Tree input on any layer the default Reconstruction Tree layer will again apply 6 6 2 Reconstructed Geometries Layer This layer reconstructs features from one or more feature collections using the current reconstruction time Typically for each input feature geometry there is a corresponding reconstructed geometry a rotated version of the present day geometry This layer is designed to handle different reconstruction methods in the one layer type Examples of reconstruction methods include rigid plate rotation and half stage rotation such as at a Mid Ocean Ridge In order to rotate the present day geometries of features a rotation hierarchy is required and this is obtained by connecting a Reconstruction Tree layer Reconstructed Geometries Options A Reconstructed Geometries layer has the following configuration options Global_EarthByte_GPlates_Coastlines_20100927 Reconstructed Geometries Input channels Reconstructable features Global_EarthByte_GPlates_Coastlines_20100927 gpml Add new connection Reconstruction tree Add new connection Advanced options Disable layer The visibility icon determines whether the reconstructed geometries are drawn in the globe and map views The Input channels section has two types of input
22. any layer specific options Once expanded you can click on the symbol to collapse the layer again Global_EarthByte_GPlates_Rotation_20100927 Reconstruction Tree W Global_EarthByte_GPlates_PresentDay_Ridges_20100927 Reconstructed Geometries ca Global_EarthByte_GPlates_PresentDay_Isochrons_20100927 Reconstructed Geometries Input channels Reconstructable features Global_EarthByte_GPlates_PresentDay_Isochrons_20100927 gpml Add new connection Reconstruction tree Global_EarthByte_GPlates_Rotation_20100927 Add new connectio Advanced options Disable layer Global_EarthByte_GPlates_PresentDay_StaticPlatePolygons_20101209 Reconstructed Geometries Global_EarthByte_GPlates_PresentDay_COBs_20101209 Reconstructed Geometries Global_EarthByte_GPlates_Coastlines_20101209 Reconstructed Geometries Caltech_Global_20101129 Default Reconstruction Tree Caltech_Global_20101129 Reconstructed Geometries Caltech_Global_20101129 Resolved Topological Closed Plate Boundaries 129 mesh 10 6 4 2 Changing layer input connections Every layer has an Input channels section that displays the current inputs and also allows the user add remove or change inputs to each layer Each layer type can have different types of input channels In the Reconstructed Geometries example above there are two types of input channel one labelled Reconstructable features and the other labelled Reconstruction tree
23. band name see the Data File Types chapter In the Raster options section you can configure the colour palette for a specific raster band used to convert each floating point pixel value to an RGB A colour value by selecting a CPT file Note that this only applies to rasters that are not already in RGB A format see the Data File Types chapter for more information on raster formats CPT files come in two forms categorical and regular Categorical is typically used for non numerical data where interpolation of values is undefined Regular is for numerical continuously varying data and is more applicable for rasters The regular CPT file allows the user to map floating point pixel values to colours with linear interpolation inbetween Selecting Use Default will map floating point pixel values to a small set of pre defined arbitrary colours Pixel values two standard deviations away from the mean pixel value will be continously mapped to the small range of colours with linear interpolation between the colours E Setting the colour palette for a non RGBA raster has no effect Configuring a raster that is not reconstructed This is the default configuration where no input channels are connected E Since there are no static polygon features connected the Reconstruction tree input channel is irrelevant Input channels Raster feature color_etopol_ice_low gpml Add new connection Reconstruction tree Add new connection
24. contains a table of properties which enable editing of values For more information on this tab consult Editing Feature Properties below View Coordinates Tab This tab contains a listing of the coordinates of the feature geometries in both present day and reconstructed time position For more information on this tab consult Viewing Coordinates below Feature ID This is a unique label for this particular feature It is a sequence of letters and numbers which is meaningful to GPlates It is not yet of interest to users Revision ID This is a unique label for this particular version of this feature It is a sequence of letters and numbers which is meaningful to GPlates It is not yet of interest to users 9 2 4 Editing Feature Properties This sequence of screenshots first shows the initial window that will appear and the following images display the options provided after selecting a property to edit Each type of property has its own editing options ipacietigs Propertes x Feature Type gpml Fault a Query Properties Ej Edit Properties E View Coordinates Property Value gpml reconstructionPlateld 308 gpml centerLineof gml validTime 750 distant future gml name THRUST FAULT BETWEEN DINARDES gpm oldPlatesHeader 34 01 0521 THRUST FAULT BETWEE gpmi dipSlip Extension gpml subcategory Thrust Add Property Delete Property Close
25. everything is a feature Many features on the globe are reconstructable and have an unchanging geometric presence that is moved around the globe according to the reconstruction tree This chapter introduces Topological features which do not have a geometry of their own defined Instead of a single fixed geometry topological features automatically construct their geometry based on the parts of other features The most useful application of this is constructing topological closed plate polygons based on the intersections of various plate tectonic boundary features 16 2 Topology Controls and Displays In addition to the Globe the various Topology Tools make use of a few other displays and controls on the Main Window The Topology Tools Task Panel and The Topology Sections Table work together to manipulate the list of features that form a topology s boundary As you edit the list of boundary features you will work back and forth between the globe the Task Panel and the Sections Table 16 2 1 Topology Canvas Tools Found on the Tool Palette the Build New Topology tool and the Edit Topology Sections tool are used to create new topologies and modify existing ones ey l Create a new dynamically closing plate polygon by adding sections of Yv Pune Now Topology other features that define a boundary Edit Topology Sections Edit the selected topological feature s sections 16 2 2 Topology Task Panel The Topology Tools Task Panel has two
26. if a line needs to be inserted or deleted at a particular timestep but the opposite case is true for the adjacent time period For example a particular topology is valid from 20 10Ma and a constituting line included in the topology is relevant for 20 16 Ma but not 16 10Ma With the line inserted the topology will therefore close correctly between 20 16Ma but fail from 16 10Ma in the given scenario the opposite case would be true if the line was deleted from the polygon In this case you need to duplicate the topology entry and effectively make two new polygons with different times of appearance or disappearance 1 e one topology valid from 20 16Ma and the other from 16 10Ma Firstly select and highlight the topology as previously described and then click on the clone feature icon on the right panel Reclicking on the topology you will see two copies of the topology entry in the Clicked Feature Table at the bottom of the window To change the validity of the feature click on the original or duplicate entry and click on the Edit feature properties icon on the right panel and change the Begin and or End time Remember to press Enter to adjust the new time period For convenience of reconstruction and preventing the overlap of polygons at 1 Myr timesteps the time of appearance may be best selected at 10Ma 1 e 20 10 15 10Ma 20 16Ma and 15 10 9 10Ma 15 10Ma You may also need to extend a line so that a topology closes This problem often arises w
27. list of boundary features Upon each reconstruction it is these features and their relationships that will be processed into the resultant polygon geometry for the topology x Clicked Topology Sections Pii NEon P peste ope ames dees es ry amp gpmtinferredPaleoBoundary 257 CAR SAM BOUNDARY gpml SubductionZone 224 CARRIBIAN PLATE BOUNDARY B y This insertion point indicates where new topology sections will be added gpml MidOceanRidge 101 SouthAmerica North America BOUNDARY from NUVEL model gpmi Isochron 190 Ridge from iso A5 from NorthAmerica 10 9Ma Features are added to the Sections Table via the controls in the Task Panel and via the table itself The insert location of the table and corresponding spot on the ordered list of boundary features will be highlighted by a special row with a large blue arrow and a message This is the Insertion Point The insertion point usually stays at the end of the list so that each new section gets appended to the topology one after the other If you wish to insert a feature elsewhere in the list of boundary sections adjust the insertion point s location using the buttons in the table All the controls for directly editing the Sections Table appear under the Actions column of the table Buttons related to a row will appear on mouse over Simply move the mouse pointer over a section in the table and the following action buttons will appear t Move the Insertion Po
28. new pole not yet implemented Time 5 00 Ma Reset to current time Step 4 Provide comment Calculated interactively by GPlates cancel SOK 15 Working with Shapefiles 15 1 Introduction ESRI Shapefiles are one of the recognised Feature Collection file formats in GPlates Loading a feature collection from a Shapefile follows the same procedure as any other feature data file see the Loading and Saving chapter 15 2 Shapefile attributes Shapefile attributes can contain meta data associated with the geospatial data This data could specify for example the feature s reconstruction plateID or the times of appearance and disappearance of the feature GPlates allows you to specify which shapefile attribute field names will be associated with GPlates feature properties such as the reconstruction plateI D GPlates records this information on disk so that in subsequent GPlates sessions the last used association will be loaded by default You can change this association at any time during a GPlates session 15 2 1 Mapping shapefile attributes The first time a shapefile has been loaded you will see the Map Shapefile Attributes dialog B Map Shapefile Attributes Associate shapefile attributes with GPlates model properties Filename World shp Model property Shapefile attribute Plate ID Slate v Feature Type TYPE Begin FROMAGE End TOAGE Name lt none gt
29. raster images each image in the sequence corresponding to a particular instant in geological time The user can instruct GPlates to load a sequence of raster image files contained within a single folder and GPlates will display the appropriate image for the reconstruction time As the user changes the reconstruction time the raster image displayed on the globe will update accordingly 3 3 2 How do I load an existing time dependent raster set A time dependent raster set is loaded using the operation Import Time dependent Raster Sequence in the GPlates File Menu This will show a dialog where the exact sequence of files can be assembled Click the Add Directory button to choose a folder containing time dependent rasters D Add Directory lt Rasters Time dependent raster sequences dynamic topography Create Folder Location jpg Places Name v Size Modified Q Search Recently Used jclark E Desktop L File System I Documents IW Music pa m Pictures H Videos EJ Downloads ba dh Add Remove 5 cancel jg Open This will fill the Import Raster file sequence dialog with those file names 8 Import Time Dependent Raster Raster File Sequence Build the sequence of raster files that make up the time dependent raster B Add files Remove selected Time Ma ile Bands A
30. the anchored plate indeterminate pole lat 78 65 lon 69 54 indeterminate pole lat 78 65 lon 69 54 lat 63 74 lon 33 52 lat 78 65 lon 69 54 lat 22 17 lon 40 52 lat 22 17 lon 40 52 indeterminate pole indeterminate pole Expand All Collapse All 11 Editing Geometries 11 1 Geometries in GPlates The geometries which GPlates handles are point multi point polyline and polygon Certain types of features contain different geometries for example a volcano uses a point to represent its position a multi point is used to represent a field of points which all have the same properties an Isochron uses a polyline to represent its centre line and a basin uses a polygon to represent its outline 11 1 1 Point A point is the most basic form of geometry in GPlates and the basis of all other geometries Ay 11 1 2 Multi point A collection of points that move as one A A E 11 1 3 Polyline A series of lines drawn end to end forming an open polygon It is assumed that the lines are non intersecting Sometimes in GPlates the direction of a polyline is important when determining the properties on either side of the line for example one side of a subduction zone represents the subducting slab while the other represents the overriding plate The direction of a polyline is determined from the start of the polyline the first point digitised to the end of the polyline 11 1 4 Polygon
31. time needs to be at the correct geological time The second step is to select a feature which belongs to the plate ID that should be changed Select the Choose Feature tool then click the mouse cursor on the feature You can confirm that you have selected the correct plate ID by checking the Current Feature Panel Now select the Modify Reconstruction Poles tool S Notice that all features belonging to the chosen plate ID are now highlighted EEEE File Edit View Reconstruction Layers Tools Palaeomagnetism Help Reconstruction Pole Q Moving plate 503 Constraints O Constrain Latitude Display Highlight children Adjustment rotation This rotation will be applied to the reconstruction pole Latitude 50 57 Longitude 159 30 Angle 4 33 Reset Apply BS as Sa SANS Pa View 3D Globe w 178 lat 21 44 e 56 56 52 Mouse la lat 13 00 lon 54 13 L J 9 amp Clicked Topology Sections oy Feature type Plate ID Name Clicked geometry EN gpml UnclassifiedFeature 503 Arabia arae e Lanml lInelassifiedFeature _ 503 Arabia anml unclassifiedGe gt 14 1 2 Adjusting a Reconstruction Pole After the feature plate has been selected with the Choose Feature tool R it can be dragged anywhere on the globe The plate can also be rotated by holding down Shift and dragging The globe can still be re orientated whilst draggi
32. using the age raster band name see the Data File Types chapter 6 6 5 Resolved Topological Closed Plate Boundaries Layer This layer generates dynamic plate polygons by closing the plate boundary at each reconstruction time The plate boundary consists of a sequence of regular features whose geometry is reconstructed and then stitched together to form a closed polygon region for each plate polygon feature See the Topology Tools chapter for more information of topological features Resolved Topological Closed Plate Boundaries Options A Resolved Topological Closed Plate Boundaries layer has the following configuration options amp Caltech Global_20101129 Resolved Topological Closed Plate Boundaries Input channels Topological closed plate boundary features Caltech_Global_20101129 gpml Add new connection Reconstruction tree Caltech_Global_20101129 Add new connection _ Advanced options Disable layer The visibility icon determines whether the resolved topological closed plate polygons are drawn in the globe and map views Here is an example of turning off the visibility of the Reconstructed Geometries layer so that only the topological polygons are visible Caltech_Global_20101129 Reconstructed Geometries gt Caltech _Global_20101129 Resolved Topological Closed Plate Boundaries The Input channels section has two types of input e Topological closed plate boundary features is one or m
33. All v Plate ID Single Colour Feature Type Open Remove Show Thumbnails Close To change the default colouring method for all feature collections select All from the drop down box at the top then choose from one of the four major categories 1 Colour by plate ID 2 Colouring all features with a single user specified colour 3 Colour by feature age the time of the feature s creation relative to the current view time 4 Colour by feature type Once you have done that a number of different options will be available in the right hand pane Some of these support the inclusion of user specified Colour Palette Files cpr A few sample cpt files are included with the sample data For further customisation you can choose to override these default colouring schemes for individual feature collections Select the feature collection from the drop down box then uncheck Use Global Colour Scheme You can now select a colouring scheme to be used for geometry originating from that feature collection 5 4 2 Manage Small Circles This operation allows you to create and maintain a list of small circle annotations to be displayed on the globe Small Circles Centre Lat Lon Radius 39 40 12 26 1 39 40 12 26 3 39 40 12 26 4 39 40 12 26 5 Remove _ Remove All To add new small circles click the Add button You can then se
34. Boundary The next step is to assign other basic property values to the Topology The geometry type is usually Boundary and this value is automatically selected for you The other basic feature properties must be set as well Plate ID Begin Time End Time Name In the final step of feature creation the feature is assigned to a feature collection All data files that are currently loaded in GPlates will be listed here as well as the lt New Feature Collection gt option Choosing any one of the existing feature collections and clicking Create will add the newly created topology feature to that collection and return the user to the GPlates main window If the lt New Feature Collection gt option is selected a new feature collection will be created to hold the new feature This feature collection will not yet have a name and is not associated with a file on disk Like all other feature collections the new one will be found in the Manage Feature Collections dialog The convenience button Create and Save adds the feature to the selected feature collection and opens the Manage Feature Collections dialog so that you may immediately save or rename the collection 16 6 bi Edit Topology Sections tool The Edit Topology Sections tool is the tool used to edit existing topology features Under this tool you will load an exiting topology into the Topology Sections Table and make edits to that ordered list of features 16 6 1 Activate the Tool
35. C g View 3D Globe 200 lat 18 94 lon 11 05 Mouse lat 5 05 lon 34 21 2 2 1 Camera Control When the Drag Globe tool is activated the GPlates globe can be re oriented freely using the mouse with a simple click and drag motion If another tool is selected the globe can still be dragged by holding down ctrl If the user wishes to adjust the camera position to a particular latitude and longitude pressing ctrl Shift L will pop up a window allowing manual entry of coordinates Set Camera Viewpoint Use the Tab key to cycle between fields a a Latitude 35 Longitude The amount of camera zoom can be controlled by the following e Zoom In via mouse wheel up e Zoom Out via mouse wheel down e Zoom Control field allowing direct entry of percentage value between 100 and 10000 Click the text field type in a new value and press Enter to change the zoom e Zoom Slider which works on a power scale e Keyboard shortcuts use the and keys to zoom in and out and the key to reset the zoom level to 1 1 100 scale The position of the camera and mouse pointer are provided along the bottom of the reconstruction view 2 3 The Menu Bar Each item in a menu is an operation Related operations are grouped into menus with the menu title indicating the common theme For example the View Menu in the image below contains operations which manipula
36. Circuits to Anchored Plate Each rotation describes the motion of a plate relative to some other fixed plate Plate ID Latitude Longitude Angle Fixed Plate ID A Se Indeterminate Indeterminate 291 a Indeterminate Indeterminate 0 0 202 291 Indeterminate Indeterminate 0 0 202 293 Indeterminate Indeterminate 0 0 291 294 Indeterminate Indeterminate 0 0 201 299 Indeterminate Indeterminate 0 0 201 301 54 8892 146 569 15 1008 101 T ta ReconstrucHon Poles Total reconstruction poles generated at Ma with anchored plate ID fo Relative Rotations Equivalent Rotations rel Anchored Plate Reconstruction Tree Plate Circuits to Anchored Plate Each equivalent rotation describes the motion of a plate relative to the currently anchored plate ID Plate ID Latitude Longitude se m 78 6497 69 54 LA LZ6Z 78 6497 69 54 17 1767 78 6497 69 54 II LABF 78 6497 69 54 171767 25 1452 71 0597 5 91001 25 1452 71 0597 5 91 001 25 1452 71 0597 5 91001 T ta Reconstr ucHon Poles Total reconstruction poles generated at Ma with anchored plate ID fo Relative Rotations Equivalent Rotations rel Anchored Plate Reconstruction Tree Plate Circuits to Anchored Plate A tree like representation of the hierarchy of relative rotations at the current reconstruction time Plate ID Fixed Plate ID Rotation rel fixed parent plate Equivalent rot
37. Palette and Task Panel A shortcut for this mode is the F11 key This mode is ideal for doing presentations Tools can still be accessed via their keyboard shortcuts While in full screen mode a new GPlates logo button will appear in the top left hand corner If you need to access the Main Menu click this button To leave Full Screen mode you can e Press F11 again e Press Esc e Click the Leave Full Screen button in the top right corner Show Bottom Panel This option allows you to show or hide the Clicked Feature and Topology Sections tables Set Projection Clicking this menu item will open a dialog allowing you to select what projection GPlates should use to display data A shortcut for this functionality can be found on the bottom of the Reconstruction View 5 2 Reconstruction View The Reconstruction View is the region of the GPlates interface which deals with plate reconstructions back through time and is displayed below rae 950026 ea Q View 3D Globe 200 S lat 18 94 lon 11 05 Mouse lat 5 05 lon 34 21 Name Description Time Controls A collection of user interface controls for precise control of the reconstruction time and animations Zoom Slider A mouse controlled slider which controls the zoom level of the Globe View camera View Controls A drop down control for selecting the projection to be used for the view and a precise percentage cont
38. Plates_PresentDay_Plate GPlates Markup E E E e 4 6 PresentDay_Ridges_20091015 gpmi GPlates Markup c E A E E a Open File Save All Close A A single row in the table corresponds to one file Column Name File Name The name of the file on disk File Format The file format type Actions A collection of operations relevant to this file If you place your mouse over the file name a tool tip appears indicating the directory the file is located in 4 3 1 Saving a file There are three different ways to save a file in GPlates The Manage Feature Collections dialog contains a table of controls and status information about the feature collections that are loaded in GPlates each row corresponds to a single feature collection and lists file name format and available actions 3 PresentDay_COBs 20100414 gpmi GPlates Markup H A Eea Item Name Function a eO p gt Manage Feature Collections Manage the feature collections which are loaded in the application File Name File Format Coastlines _20091014 gpml GPlates Markup DNSCO8GRA_6m gpml GPlates Markup PresentDay_COBs_ 20100414 gpml GPlates Markup PresentDay_Isochrons_20091015 gpml GPlates Markup a GPlates Markup PresentDay_Ridges_20091015 gpml GPlates Markup Open File Save All Save e Saves the cu
39. Polygon features Add new connection Age grid feature Add new connection The raster is rendered as a non rotating or non reconstructing georeferenced raster in this example a global raster Changing the reconstruction time makes no difference unless the raster feature is a time dependent raster in which case the image itself will change over time but will still remain stationary on the globe Tat gr TEE re gt ya SALEN amp i 3 I r EN pe ini ey wy te 7 me 34 00 ma gt fa faa o gt g View 3D Globe 112 lat 0 71 lon 12 48 Mouse lat 41 36 lon 7 Configuring a raster that is reconstructed using static polygons This configuration does everything the above configuration does including resolving a time dependent raster over time in addition to reconstructing the raster The reconstruction is peformed using a set of static polygons Conceptually the single raster image or time resolved raster image for a time dependent sequence is cookie cut into multiple polygon shaped pieces using the present day location of each static polygon Then each polygon is reconstructed using its reconstruction plate ID As each polygon is reconstructed back in time it rotates independently for polygons with different plate IDs and transports its cookie cut piece of raster image with it Only polygons whose valid time range between age of appearance and disappearance includes the cur
40. TES4 line format polyline header does not match the actual number of points in the polyline e A warning will not have resulted in any data loss but you may wish to investigate the problem in order to verify that GPlates has corrected the errors in the data in the way you would expect and to be aware of incorrect data which other programs may handle differently Recoverable error e A recoverable error is an error generally an error in the data from which GPlates is able to recover although some amount of data had to be discarded because it was invalid or malformed in such a way that GPlates was unable to repair it e Examples of recoverable errors might include o When the wrong type of data encountered in a fixed width attribute field for instance text encountered where an integer was expected e When a recoverable error occurs GPlates will do the following o Retain the data it has already successfully read o Discard the invalid or malformed data which will result in some data loss o Continue reading from the data source GPlates will discard the smallest possible amount of data and will inform you exactly what was discarded Terminating error e A terminating error halts the reading of data in such a way that GPlates is unable to read any more data from the data source e Examples of terminating errors might include o A file system error o A broken network connection e When a terminating error occurs GPlates will re
41. age Colouring Manage Small Circles Show Point Features Show Line Features Show Polygon Features Show Multipoint Features Show Arrow Decorations Features Show Text Features Configure Text Overlay Configure Graticules Choose Background Colour Show Stars 2 5 6 Help About 3 Data File Types 3 1 Introduction This chapter covers the visualisation techniques within GPlates which image formats are able to be loaded into GPlates and how to go about doing this 3 2 Rasters in GPlates GPlates has the facility to display raster images on the globe GPlates can also reconstruct rasters back in geological time with the assistance of a set of static polygons static meaning the shape of the polygons do not change in contrast to topological plate polygons which have dynamic shapes see the Topology Tools chapter For more information on reconstructing rasters please see the More on Reconstructions chapter 3 2 1 What are raster images A raster image is one formed by a 2 dimensional rectangular grid coloured by points A single point of colour in the raster image is known as a pixel Each pixel is positioned at one of the grid points and every grid point has a pixel positioned on it The ability to display raster images on the globe enables the user to superimpose any kind of imagery or gridded data such as satellite imagery topography bathymetry etc on the surface of the globe to be viewed at the same time as reconstr
42. al features which you are creating or editing in GPlates 9 1 Tools for Interacting with Features To interact with features the following tools can be used Click a geometry to choose a feature Shiftt click to query A S P yv Drag to move a vertex of the current feature You can still drag the globe around oP a n i Delete Vertex X Remove a vertex from a multi point polyline or polygon geometry Split Feature Click to split the geometry of the selected feature at a point to create two features To review information on all Tools please consult the Introducing the Main Window chapter 9 2 X Choose Feature Tool 9 2 1 Clicked Geometry Table You can query a feature by first selecting then click the mouse cursor on what you want to query The information will be displayed in the Clicked Geometry Table Clicked Selected Feature type Plate ID Clicked geometry gpmi Fault 706 SOUTH ATLAS SHEAR ZONE TELL ORAN MES gpml centerLineOf The table will list all features that have geometry in proximity to the point that was clicked This is useful in J situations where multiple geometries from different features happen to lie on top of each other In this case the mouse click will populate the Clicked Geometry Table with one entry for each geometry You can then use to the Clicked Geometry Table to select the desired geometry As you select each entry in the Clicked Geometry Table its geometry as displaye
43. animation 7 4 1 Animation Dialog Ammate Animate from 140 00 Ma to Ma with an increment of 100 B M per frame Reverse the Animation by swapping the start and end times Options Frames per second 5 00 S Finish animation exactly on end time _ Loop _ Close this dialog when animation starts Playback fat Current time 44 00 Ma Range This group of controls specifies the time range that the animation should cover The Use Main Window buttons are a convenient way of quickly entering the time that the main window is currently viewing Options Additional options to fine tune the behaviour of the animation are presented here The Frames per second number controls the rate at which GPlates will limit the display of animation frames when presenting an animation interactively Larger numbers produce a slower animation E If calculating the next step of the animation takes too long perhaps due to a large amount of data GPlates may skip some frames to try and keep the animation running at the correct rate Playback These controls allow simple playback and seeking within the animation from this dialog They behave identically to the equivalent controls found in the Reconstruction View 8 Export 8 1 Introduction The Export function allows users to save scientific data or images to files 8 2 Export dialog The Export dialog can be accessed via the Reconstruction menu by cho
44. ation rel anchored mie ie indeterminate pole 0 00 indeterminate pole lat 22 17 lon 40 52 13 14 lat 22 17 lon 40 52 lat 63 74 lon 33 52 24 60 lat 78 65 lon 69 54 indeterminate pole 0 00 lat 78 65 lon 69 54 indeterminate pole 0 00 lat 78 65 lon 69 54 indeterminate pole 0 00 lat 78 65 lon 69 54 lat 1 52 lon 62 24 9 50 lat 63 45 lon 33 67 indeterminate pole 0 00 lat 78 65 lon 69 54 indeterminate pole 0 00 lat 78 65 lon 69 54 lat 46 00 lon 15 22 22 82 lat 37 52 lon 6 65 lat 30 90 lon 17 50 indeterminate pole Expand All Collapse All T ta ReconstructHon Poles Total reconstruction poles generated at Ma with anchored plate ID fo Relative Rotations Equivalent Rotations rel Anchored Plate Reconstruction Tree Plate Circuits to Anchored Plate Each branch can be expanded to list the circuit of relative rotations from a plate to the anchored plate Plate ID Circuit Fixed Plate ID Rotation rel fixed parent plate Equivalent rotation rel anchored plat P indeterminate pole wo lat 78 65 lon 69 54 indeterminate pole 0 lat 78 65 lon 69 54 lat 63 74 lon 33 52 er lat 78 65 lon 69 54 lat 22 17 lon 40 52 lat 22 17 lon 40 52 indeterminate pole 0 indeterminate pole Expand All Collapse All 7 3 6 Assign Plate IDs Assigns reconstruction plate IDs and optionally time of appearan
45. ature is a range of geological time i e from 65Ma to 0Ma present day 9 2 3 Querying Feature Properties To query the properties of the current feature either click A at the bottom of the Current Feature Panel or press Ctr1 R to invoke the corresponding operation in the Edit Menu The Feature Properties dialog will appear containing a complete listing of the properties of the current feature Feature Propertes El Edit Properties zI View Coordinates Feature ID GPlates 03cle39d 8141 4832 9b18 6b244f0e8286 Revision ID GPlates 2da055b9 f0af 4af2 82f4 348dblacl18d gpml reconstructionPlateld amp gpml centerLineOf gmi baseCurve gml posList gml validTime ke gml begin 750 distant future gpml oldPlatesHeader gpmi dipSlip Extension gpml subcategory Thrust This geometry was reconstructed using the equivalent rotation Euler pole lat lon Angle jo degrees Plate ID relative to the anchored plate ID at time Ma You can keep this dialog open and continue to use the Choose Feature Tool to click on new features the Feature Properties dialog will be automatically updated Feature Type This is the type of feature e g fault mid ocean ridge subduction zone Query Properties Tab This tab contains a complete listing of the properties of the current feature presented in a concise structured form which is easy to read but does not allow editing of values Edit Properties Tab This tab
46. ave All Close and two layers are automatically created DER amp Caltech_Global_20101129 Resolved Topological Closed Plate Boundaries amp Caltech_Global_20101129 Reconstructed Geometries One layer reconstructs the regular features that are referenced by the plate polygons and the other layer does the work of stitching the features together intersecting them and creating the dynamic polygon boundary J Because there are two layers the dynamic plate polygon boundaries can be made visible while the features used to construct the dynamic boundary can be made invisible 6 5 2 Layers created by the user Layers can be explicitly created by the user db Add new layer After selecting Add new layer at the top of the Layers dialog you can then select the type of layer you want to create Here is example of creating a new Calculated Velocity Fields layer 3 Add New Layer Layer Type Calculated Velocity Fields ng Lithosphere motion velocity vectors will be calculated dynamically at mesh points that lie within resolved topological boundaries or topological networks A new layer is then created and inserted at the top of the layer stack db Add new layer amp Layer 21 Calculated Velocity Fields th Global_EarthByte_GPlates_PresentDay_Ridges_20100927 Reconstructed Geometries bal The layer name will be Layer suffixed with an integer for example Layer 21 It is not based off
47. be deleted The vertices on either side of the removed vertex will now be connected directly creating a new polyline or polygon In the case of multi point geometry when the user clicks on an existing point the point will be removed Note that if a vertex is removed from a polygon the resulting geometry will still be a closed polygon as Fte long as there are sufficient remaining vertices GPlates requires at least three distinct points to define a polygon If there are only two distinct points remaining the geometry will become a polyline Note that if a vertex is removed from a polyline the resulting geometry will still be a single continuous polyline as long as there are sufficient remaining vertices GPlates requires at least two distinct points to define a polyline If there is only one distinct point remaining the geometry will become a point Note that if a vertex i e point is removed from a multi point geometry which contains only two points it will become a point geometry It is invalid to remove a vertex from a single point geometry In order to remove the geometry entirely the feature will have to be deleted O 11 2 4 lt P Split Feature Tool When the user clicks on a line the clicked geometry will be split at that point into two geometries The line will highlight yellow when the mouse is close enough to the line to perform a split After the split the original feature will contain one geometry and a new feature will b
48. ce disappearance to a set of features This is typically done to features that do not yet have plate IDs or valid time ranges but it can also override an existing plate ID of a feature with a new plate ID Two sets of features are required for this process e A set of partitioning features These are the features that the plate IDs and optionally time ranges are copied from These features must have or generate polygon geometry and hence can be either static polygon features where the polygon geometry does not change shape or Topological Closed Plate Polygons features where the polygon shape changes dynamically as the reconstruction time changes These features remain unmodified by this process e A set of features to be partitioned These are the features that the plate IDs and optionally time ranges are copied to And also depending on the partitioning option chosen the geometry s in these features can be partitioned cookie cut into several smaller geometries still belonging to the one feature Hence these features are modified by the addition or modification of plate ID and optionally time range properties and also their geometry property s depending on the partitioning options selected Here is an example of selecting partitioning features that are static polygons Partitioning Polygons Specify topological dosed plate boundaries or non topological static polygons from the following files File Name 1 Global_Ea
49. d on the globe will highlight to show you which geometry you are selecting Most features have a single geometry but some do have multiple geometries For these features all geometries are highlighted however the geometry that was actually clicked on is displayed in white whereas the other geometries belonging to that feature are displayed in grey 9 2 2 Current Feature Panel Current Feature Type gpml MidOceanRidge Name Mid Atlantic Ridge Purdy ID T moo aani time Clicked geometry oml unclassifiedGeometry Feature collection EVE ised The Current Feature Panel summarises the pertinent properties of the current feature This is the starting point for further interaction with the feature It contains e Type of feature e Name of the feature e Plate ID of the feature used for reconstruction e Conjugate plate ID of the feature if it has one e Plate IDs for the left and right sides of the feature if applicable e Life time of the feature the period for when it exists e The purpose of the clicked geometry e Buttons to o Query Feature o Edit Feature o Copy Geometry to Digitise Tool o Clone Feature o Delete Feature The Edit menu also provides access to e Undo ctr1 z e Redo ctrity A Query Feature Ctr1 R B Edit Feature Ctr1 E sf Copy Geometry to Digitise Tool ad Clone Feature w Delete Feature De1 x Clear Selection J The valid life time of the fe
50. der is unimportant but the raster image files must adhere to three rules 1 Each raster image file must be in a raster image format which GPlates is able to handle Any format available to a single imported raster is also available to a time dependent raster sequence 2 Each raster image file must have a file name of the form time _ jpg or _time jpg where time is an integer value representing a number of millions of years before the present day this is the instant of geological time to which that raster image corresponds Note that jpg is just an example it could be any valid file format extension For example the files e topography 0 jpg topography 1 jpg topography 2 jpg together form a time dependent raster set In the above example the image lasts from 0 2Ma and has time steps of 1Ma Note that the filename prefix does not need to be common across all the filenames For example e b topography 0 jpg e a topography l jpg e c topography 2 jpg will produce the same sequence ordered by time 4 Loading And Saving Before you load any data into GPlates the globe will appear as a blank sphere in order to start with GPlates you will need to know how to load save and unload data You can still manipulate the view of the globe even though it s blank See Chapter 5 Controlling the View for more details 4 1 Introducing Feature Collections When a data file is loaded in GPlates it is loaded
51. e where it will be used to construct part of the topology s boundary Continue creating the intended boundary of the new topology by selecting a feature to focus it and then clicking Add Focused Feature to insert it into the Topology Section Table It is recommended to create a new topology by cycling around the boundary systematically either a clockwise or counter clockwise and appending features to the end of the Topology Sections Table 16 5 3 Editing the Sections Table If you have discovered that you forgot a feature in the middle of the boundary list list or realise you want to modify the ordering of the Sections in the Table then you may change the insert point via the Actions column of the table and continue with the same steps as above Focus a feature on the Globe then click the Add Focused Feature button Adding a feature does not change the insertion point so be aware if you perform an Insert operation out of sequence 16 5 4 Creating the new feature Once you are satisfied with the entries in the Topology Sections Table and the resultant polygon geometry of the Topology itself then you may create the new Topology via the Apply Create button on the Topology Tab of the Topology Task Panel This action will lead you through a series of dialogs to finalise the creation process In the first step you will choose the Feature Type of the new Topology Currently GPlates supports only one type of topology TopologicalClosedPlate
52. e Selecting a property from the table and selecting Delete will delete the property from the feature Feature Properres Property gpml reconstructionPlateld Edit Polyline i 1 1 I L T I i Append points Lon 0 0000 Lat 0 0000 12 Creating New Features This chapter aims to provide the reader with information and instructions for digitising new features in GPlates 12 1 Digitisation GPlates allows the user to create features on the globe from aseismic ridges to volcanoes To create a new feature a user first digitises a new geometry then specifies the additional properties for that feature The geometries which GPlates handles are point polyline a series of lines drawn end to end forming an open polygon and polygon Certain types of features require certain geometries for example a volcano uses a point to represent its position an isochron uses a polyline to represent its center line and a basin uses a polygon to represent its outline 12 1 1 Digitisation Tools GPlates offers three digitisation tools in the Tool Palette IV Polyline Geometry 2 Point Geometries Jf Each tool can be used to create any of the GPlates GPML features however it is the user s responsibility to ensure that the correct geometry is digitised for the intended feature type Polygon Geometry After choosing a geometry tool you can begin adding control points to the globe by clicking on an area
53. e attributes you want to view To view shapefile attributes for a single feature Shapefile attributes for a single feature can be viewed through the Query Feature Properties dialog see the Interacting with Features chapter 15 2 5 Editing Shapefile attributes Shapefile attributes can be edited through the Edit Feature Properties dialog see the Interacting with Features chapter Only the value of shapefile attributes can be edited Field names and field types cannot be edited You cannot create new shapefile attribute fields or delete existing shapefile attribute fields 15 3 More about the Shapefile format The ESRI Shapefile format is a file format allowing storage of geospatial vector graphics data and metadata An ESRI Shapefile is a collection of at least 3 files with file extensions shp shx and dbf A shapefile called mydata will consist of the files mydata shp mydata shx mydata dbf The geospatial data are stored in the shp and shx files the meta data attributes are stored in the dbf file When loading a shapefile feature collection you only need to select the shp file the shx and dbf files are loaded automatically The file filter used in the Open Feature Collection dialog will show only the shp form of shapefiles The ESRI shapefile specification can be downloaded from http Awww esri com library whitepapers pdfs shapefile pdf 16 Topology Tools 16 1 Introduction In GPlates
54. e created to contain the other geometry Both features will have the same properties and will only differ in their geometries and their feature ID which is their uniqueness identifier This tool works only on a feature selected with the Choose Feature Tool id and currently it only works if the feature s geometry is a polyline Features containing point multi point or polygon geometry cannot be split 11 3 In the Feature Properties Dialog The controls for directly editing the coordinates used by geometry appears as a table with Lat Lon and Actions columns Click a row of the table to select it and the following action buttons will appear Insert a new row above Insert a new row below Delete row e Double clicking an entry in the table lets you edit a coordinate directly o The Valid Geometry line will indicate if the coordinates in the table can be turned into correct geometry It will indicate an error if there is something invalid about the coordinates such as a lat lon of 500 or similar e The Append Points spin boxes are designed to be a convenient means of data entry if you need to enter some points from a hard copy source o Click in the Lon to start entering new coordinates Type in a lon value press TAB type in a lat value press TAB to move to the button press SPACE to activate that button The new coordinate line will be added to the table and GPlates will prepare to receive the next line of input
55. e representation of the hierarchy of relative rotations at the current reconstruction time Plate ID Fixed Plate ID Rotation rel fixed parent plate Equivalent rotation rel anchored pla Gel 0 indeterminate pole 0 00 indeterminate pole lat 22 17 lon 40 52 SASA lat 22 17 lon 40 52 lat 63 74 lon 33 52 24 60 lat 78 65 lon 69 54 indeterminate pole 0 00 lat 78 65 lon 69 54 indeterminate pole 0 00 lat 78 65 lon 69 54 291 indeterminate pole 0 00 lat 78 65 lon 69 54 225 lat 1 52 lon 62 24 9 50 lat 63 45 lon 33 67 i 294 indeterminate pole 0 00 lat 78 65 lon 69 54 indeterminate pole 0 00 lat 78 65 lon 69 54 lat 46 00 lon 15 22 22 82 lat 37 52 lon 6 65 lat 30 90 lon 17 50 indeterminate pole Expand All Collapse All 10 3 4 Plate Circuits To Stationary Plate This tab of the Total Reconstruction Poles dialog can be used to trace a series of total reconstruction poles from any given plate ID back to the top of the hierarchy the anchored plate ID It is useful to quickly identify the other plate IDs that a chosen plate ID depends on T ta ReconstrucHon Poles Total reconstruction poles generated at Ma with anchored plate ID os Relative Rotations Equivalent Rotations rel Anchored Plate Reconstruction Tree Plate Circuits to Anchored Plate Each branch can be expanded to list the circuit of relative rotations from a plate to
56. e the thin gap along the mid ocean ridge between South America and Africa This is an example of a thin ridge aligned polygon popping out as you reconstruct backwards in time because its time of appearance is after the current reconstruction time 34Ma in the example Currently self intersecting polygons even if only negligbly intersecting are ignored which can result in holes in the raster The static polygons GPML file distributed in the GPlates sample data currently contains no self intersecting polygons Jn the next release GPlates will be modified to handle self intersecting polygons Configuring a raster that is reconstructed using static polygons and present day age grid This configuration builds on the previous configuration Configuring a raster that is reconstructed using static polygons by adding an age grid raster When an age grid is not used the static polygons pop in and out as whole polygons when the reconstruction time changes Thus the subduction and accretion of oceanic crust is simulated using lots of thin polygons with small differences in age The age grid takes this even further by providing per pixel rather than per polygon age comparisons to provide a more continuous transition at plate boundaries Here the age of the pixel is used instead of the age of the polygon Pixel values in the age grid raster that are NaN a special floating point value representing Not a Pte number represent non oceanic crus
57. editing software e g drawing tools in Photoshop or GIS software e g ArcGIS mapping tools The Tool Palette includes camera positioning tools feature selection tools and drawing tools A tool is activated by clicking on it only one tool can be active at any time The task panel will reflect the current tool that is activated Drag to re orient the globe Shift drag to rotate the globe Click to zoom in Shift click to zoom out Ctrl drag to re orient the globe Click to measure distance between points or measure the selected feature s geometry Click a geometry to choose a feature Shift click to query immediately Ctrl drag to re orient globe Digitise Polyline Geometry Click to draw a new vertex ctrl drag to re orient the globe Digitise Multi point Geometry ca Digitise Polygon Geometry Click to draw a new vertex Ctrl drag to re orient the globe EZ Click to draw a new point ctrl draqg to re orient the globe Drag to move a vertex of the current feature You can still drag the Move Vertex globe around iow Insert a new vertex into the feature geometry Remove a vertex from a multi point polyline or polygon geometry Split Feature Modify Reconstruction Pole Click to split the geometry of the selected feature at a point to create two features Drag or Shift drag the current geometry to modify its reconstruction pole ctrl drag to re orient the globe by holding down ctr1 Create a new dynamically closin
58. elds layer When a Resolved Topological Closed Plate Boundaries layer is automatically created when the appropriate feature collection is loaded GPlates will search for all Calculated Velocity Fields layers and connect their input to the output of the new Resolved Topological Closed Plate Boundaries layer Eas 7 Reconstructions 7 1 Introduction The motions of tectonic plates through geological time may be described and simulated using plate tectonic reconstructions Plate tectonic reconstructions are the calculations of the probable positions orientations and motions of tectonic plates through time based upon the relative plate to plate positions of plates at various times in the past which may be inferred from other data Geological geophysical and paleo geographic data may be attached to the simulated plates enabling a researcher to trace the motions and interactions of these data through time Geological time instants in GPlates are measured in units of Mega annum Ma in which 1 Ma is equal to one million years in the past For example the allowable range for reconstructions is from 0 to 10 000 Ma ie present day to 10 years ago The current age of the Earth is approximately 4 5 x 10 a years 7 2 Main Window Interface Components gt a GPlates File Edit View Reconstruction Layers Tools Palaeomagnetism Help Current Feature Type Time 35 00 2 ma D gt 4 lt 4 D gt mp gemitsec
59. em and colouring settings are not currently remembered and must be restored manually 4 2 4 How do I load a raster image in GPlates To load a raster image into GPlates it must first have a GPML file associated with it This is done by importing the raster into GPlates This only needs to be done once for each raster After that you can simply load the GPML file created during the import process into GPlates like you would a regular feature collection For information on how to import a raster please see the Data File Types chapter 4 3 The Manage Feature Collections Dialog This dialog window enables you to load new files and save reconfigure and unload currently loaded files This is where you will find any file specific operations To control how GPlates uses the data from those files please see the Layers chapter and related functionality How to show The Manage Feature Collections Dialog 1 Go to the File Menu in the menu bar 2 Click on Manage Feature Collections menu item shortcut ctr1 gt O Manage Feature Collections Manage the feature collections which are loaded in the application File Name File Format Actions 1 Coastlines_20091014 gpm GPlates Markup ae AG z Ali 2 DNSCO8GRA_6m gpml GPlates Markup H 6 B 2 3 PresentDay_COBs_20100414 gpml GPlates Markup H A G we 4 4 PresentDay_Isochrons_20091015 gpml GPlates Markup H A ey J 5 Global_EarthByte_G
60. ensed for distribution under the GNU General Public License GPL version 2 1 4 Further Information For more information about GPlates contact us http www gplates org contact html 2 Introducing The Main Window This section describes the Main Window the heart of the GPlates user interface Below we present annotated screenshots of GPlates label the key areas of the window and provide a brief overview of each 2 1 The Main Window When you start GPlates the first window you will encounter is the Main Window This contains your view of the globe and is the starting point of all tasks within GPlates It is here that you can control your view of the globe choose your reconstruction time load and unload data and interact with geological features GPlates rile Edit View Reconstruction Layers Tools Palaeomagnetism Help Al Current Feature 65 00 M siveContinentalBoundary Name COB NW Africa conj Sout Plate ID 701 Valid time from 110 to future Clicked geometry gpmlI centerLineOf Feature collection PresentDay_COBs_201004 a So we Feature type Plate ID Name gpmi lsochron 701 CENTRAL ATLANTIC AFRICA SOUTH AMERICA AN Lanmt LinclassifiedFeatiure _ 714 Northwest Africa a This region of the Main Window contains the titles of the menus Ho o Me Palette A collection of tools which are used to interact with the globe and geological features via the mouse po
61. example if a feature to be partitioned has two geometries where one geometry overlaps plate A and the other geometry overlaps plate B then the feature to be partitioned will get split into two features one feature containing the first geometry and plate ID A and the other containing the second geometry and plate ID B Note that although the feature is split into two features the geometries are not partitioned cookie cut and hence the geometry data remains unmodified e Partition cookie cut feature geometry into polygons and copy feature properties Partition all geometries of a feature to be partitioned into the partitioning polygons intersecting them This can create extra features for example if a feature to be partitioned has only one geometry but it overlaps both plate A and plate B then it is partitioned into one or more geometries fully contained by plate A and likewise for plate B These partitioned geometries will now be contained by two features since they have different plate IDs If the polygons do not cover the entire surface of the globe then it is possible for some features to be partitioned or partitioned geometries to fall outside all partitioning polygons In this situation the feature to be partitioned is not modified and will retain its original feature properties such as reconstruction plate ID VirtualGeomagneticPole features are treated differently these features are assigned to the polygon whose boundary con
62. g plate polygon by adding sections of Dail NTa Tanala wer DULY INCW LOPOULOPYy D other features that define a boundary Edit the selected topological feature s sections The availability of certain tools will change depending on what you currently have selected For instance the Modify Reconstruction Pole tool can only be used once a feature to be modified has been selected with the Choose Feature tool All of the geometry editing tools are context sensitive and can be used to operate on an existing feature or geometry that you are in the process of digitising The tools are also accessible via the Tools menu which also shows the shortcut key for each tool The Tools menu also contains a check box Use Small Icons that reduces the size of the tool icons in the Tool Palette This is useful if your screen resolution is low enough to force the bottom tools off the screen this can happen if you are using a low resolution screen projector 2 5 List of Menu Operations e Tables of shortcuts and accelerators can be found in Appendix A of the user manual e A description of the operations within each menu will be explained in further detail in their respective chapters J Clicking on a menu item from the list below will take you to the appropriate chapter for further information 2 5 1 File e New Window Creates a new instance of GPlates Currently each instance created this way is completely separate with its own main window and dialogs A
63. hat position on the line The line will highlight yellow when the mouse is close enough to the line to insert a vertex This vertex may then be dragged to a new position using the move vertex tool E When clicking on a line segment the vertex will always be inserted directly on the line segment even though it s possible to highlight a line segment and click on it when the mouse is not directly over the line If the mouse is too close to an existing vertex then you will not be able to insert a new vertex you can tell Fte this is the case when the line segment no longer highlights yellow If you need to insert a new vertex very close to another vertex you will need to zoom in The Insert Vertex tool can also be used to extend a polyline at either end If you move the mouse such that it is closer to one of the endpoints than any other point in the polyline then you can see visually that a subsequent mousse click will extend the polyline by one line segment The same applies to a polygon except the two endpoints are now the first and last vertex of the polygon and the line segment between the last and first vertex will be replaced with two line segments that link the first and last vertex with the inserted vertex If the current geometry is a multi point a new point will be created at the click position o 11 2 3 4 Delete Vertex Tool If the current geometry is a polyline or polygon when the user clicks on an existing vertex that vertex will
64. hen using rotation files that are significantly different and therefore the new location of a particular plate D assigned line may mean that a topology is no longer closed This method is best restricted to instances where the line only needs to be extended a relatively short distance and in a largely straight line This is achieved by using the Insert Vertex icon as previously described Because the topology already exists as an entry the new line will be automatically incorporated and the topology should be successfully closed It is wise to check the polygons through time that utilize this line to ensure that no other existing polygons have been changed Last updated 2010 12 22 17 54 47 EST
65. ify reconstruction time choose an arbitrary reconstruction time Note Present day should be selected when assigning plate ids to VirtualGeomagneticPole features The partitioning polygon features are reconstructed to the specified reconstruction time before testing for overlap intersection with the features to be partitioned The geometry in features to be partitioned effectively represents a snapshot of the geometry of those features at the specified reconstruction time In other words the features to be partitioned effectively contain geometry at the reconstruction time regardless of whether they have a reconstruction plate id property or not However most features in GPlates contain present day geometry so this distinction is not that important typically Present day will be selected Specifying how to partition features These three options determine how features are partitioned Copy feature properties from the polygon that most overlaps a feature Assign to each feature to be partitioned the plate ID of the partitioning polygon feature that its geometry s overlaps the most Copy feature properties from the polygon that most overlaps each geometry in a feature Assign to each geometry of a feature to be partitioned the plate ID of the partitioning polygon feature that its geometry overlaps the most Note that a plate ID cannot be assigned to a geometry of a feature so instead extra features are created as necessary For
66. in the Feature Collection All data in GPlates are represented as features e g MOR volcano etc whether geological data or reconstruction data Regardless of the file format all features will be contained internally as GPlates features However GPlates will remember the name and format of the file for saving All data loaded in GPlates are represented as features all data manipulation functions are operations upon features GPlates offers a rich variety of feature types enabling GPlates to handle geographic paleo geographic geological and tectonic data Basin Coastline Craton Fault Hotspot Isochron Mid Ocean Ridge Seamount Subduction Zone Suture and Volcano are just some of the many feature types handled by GPlates The meta data attributes of data are contained within named properties of the features GPlates is able to load and save a number of data file formats e g PLATES4 When a data file is loaded in GPlates the data will be converted to the appropriate types of features and placed into a Feature Collection One Feature Collection in GPlates corresponds to one data file on the disk Even though the data have been converted to GPlates features GPlates will remember the name and original format of the file for saving When the features are saved they will be converted back to their original data format It is also possible to save features into different data formats using the Save As or Save a Copy buttons in the Manage
67. ing 3 Drag these files into the GPlates Main Window It is also possible to add cpt files to the Manage Colouring dialog in this way 4 2 3 The Open Recent Session menu Whenever you close GPlates it automatically remembers which set of files you were working on last time You can resume your previous session by using the menu 1 Go to the File Menu in the menu bar 2 Scroll down to the Open Recent Session submenu 3 Select the menu entry corresponding to the set of files you want GPlates to load E New Window Ctrl N f Open Feature Collection Ctri O 7 files in data on Wednesday 15 December 2010 2 35 39 PM Import Raster 4 files in bundle0 9 10 on Friday 10 December 2010 7 42 09 PM 10 files in data on Friday 10 December 2010 7 41 59 PM 3 files in bundle0 9 9 on Friday 10 December 2010 7 41 30 PM 2 files in gzip on Friday 10 December 2010 7 40 15 PM 2 files in AuScope Dec 2007 Release on Friday 10 December 2010 7 38 35 PM 1 file in earthbyte on Friday 10 December 2010 7 37 45 PM Import Time Dependent Raster Manage Feature Collections Ctri M View Read Errors View Total Reconstruction Sequences View Shapefile Attributes gt Quit Ctri Q An entry for each prior session of GPlates can be identified by the number of files that were loaded the name of the directory that all the files have in common and the date they were last in use Please note that connections from the Layers syst
68. int to the row above this one new sections will be added to the topology before this one Move the Insertion Point to the row below this one new sections will be added to the topology after this one eg Remove this section from the list It will no longer contribute to the topology ta Reset the Insertion Point to the last entry This causes insert operations to simply append features to the Sections Table If you need to distinguish between similar features used in the topology click on a row of the table This will highlight that row and also highlight the corresponding geometry on screen The Feature Type Plate ID and Name columns provide a quick summary of the Section The background colour of a row will change to red if there are some problems resolving that part of the topology This may occur for example when you have loaded a file containing the topology definitions but have yet to load a file containing the features that were used to build that topology 16 4 Topology Drawing Conventions While a topology feature is under edit GPlates will draw the topology and its referenced features with certain highlights and colors The focused feature will always be drawn in white The topology s resultant boundary polygon will be drawn in light gray All the topology s resultant vertices both those from the source features and those computed as intersection points will be highlighted with gray dots The current Insertion
69. inter Time Controls A collection of user interface controls for precise control of the reconstruction time Animation Controls A collection of tools to manipulate the animation of reconstructions 5 Zoom Slider A mouse controlled slider which controls the zoom level of the Globe View camera Task Panel Task specific information and controls which correspond to the currently activated tool 7 View Control Controls which projection is used to display data and the exact zoom level as a percentage Camera Coordinate An information field which indicates the current globe position of the Globe View camera Mouse Coordinate An information field which indicates the current globe position of the mouse pointer 10 Clicked Geometry Table Displays a summary of each geometry or feature touched by the last mouse click The appearance of the Main Window particularly the layout of the different window components will change as GPlates continues to evolve 2 2 Reconstruction View The reconstruction view provides the user with a display of their data on the GPlates globe or map reconstructed to a moment in time Control of the current reconstruction time is located under the menu bar on the left see image below The time can be controlled by both a text field forwards and backwards time buttons and the animation slider In addition the shortcut ct r1 T to enter a time value in the text field Time 95 00 lma p gt 44
70. internally inside GPlates is the same for same sized images Floating point images There also exist integer formats but the floating point formats are much more common and useful in general These images have one or more raster bands where each band has a single channel a single float point value per pixel in the image Most images have a single raster band Supported file formats include standard NetCDF formats NetCDF file typically have the filename extension nc or grd These formats are not compressed and since they are usually used in high resolution scenarios they can be quite large RGB and RGBA images can be visualised directly since they already contain colour values Red Green and Blue per pixel Floating point images require a mapping from a float point value to a colour value RGB This is done in the Raster options part of the raster layer A new layer becomes visible in the Layers dialog for each raster loaded or imported into GPlates For information on the Raster options please see the Layers chapter 3 2 3 How do I load a raster image in GPlates To load a raster image into GPlates it must first have a GPML file associated with it This is done by importing the raster into GPlates This only needs to be done once for each raster After that you can simply load the GPML file created during the import process into GPlates like you would a regular feature collection see the Loading And Saving chapter 3 2 4 How do
71. ions intersect both adjacent neighbours forming a completely closed circuit certain types of geometry Remember that you can also use the Clicked Feature Table to help you pick out Checkable items in the Layers menu can be used to reduce visual clutter by switching off the display of features when they overlap 16 5 a4 Build New Topology tool The Build New Topology tool is the tool used to create new topology features from existing regular non topological features You will select a series of features in an ordered fashion moving around the intended boundary of the topology 16 5 1 Activate the Tool First click on the Build New Topology tool button You may need to deselect a feature you are currently working on for this tool to become available Initially the new topology will have an empty list of sections As you add sections to the topology the Topology Sections Table will become populated with the features 16 5 2 Select Features to become Topology Sections Next select a feature by clicking on it on the Globe E You do not have to switch to the Choose Feature Tool The Build Topology Tool is a specialised version of choosing features If more than one feature is under the click point you can use the Clicked Table to further refine your selection to the proper feature Once you have identified the desired feature click the Add Focused Feature button The referenced feature is transferred to the Topology Sections Tabl
72. ive plate tectonic reconstructions geographic information system GIS functionality and raster data visualisation GPlates enables both the visualisation and the manipulation of plate tectonic reconstructions and associated data through geological time GPlates runs on Windows Linux and MacOS X GPlates File Edit View Reconstruction Layers Tools Palaeomagnetism Help Time 65 00 2 ma gt IK 44 D gt n Current Feature Type 5siveContinentalBoundary Name COB NW Africa conj Sout Plate ID 701 Valid time from 110 to future Clicked geometry SEELI gpml centerLineof Feature collection PresentDay_COBs_ 201004 ABAS a tin gunEEeenniememnindican 3 View 3D Globe w v 100 lat 0 00 lon 0 00 Mouse lat 39 40 lon 90 00 off globe 9 amp Clicked Topology Sections 5 oy Feature type Plate ID Name LA gpmi lsochron 701 CENTRAL ATLANTIC AFRICA SOUTH AMERICA AN SES Lanml LnrlassifiedFeature _714 Northwest Africa ao IY T 1 2 1 What is a Plate Tectonic Reconstruction The motions of tectonic plates through geological time may be described and simulated using plate tectonic reconstructions Plate tectonic reconstructions are the calculations of the probable positions orientations and motions of tectonic plates through time based upon the relative plate to plate positions of plates at various times in
73. le was called mydata shp the mapping information will be stored in the same folder in a file called mydata shp gplates xml The next time a user loads mydata shp GPlates will look for the file mydata shp gplates xml If this mapping file is found GPlates will use the mapping contained in it and will not force the user to use the Map Shapefile Attributes dialog 15 2 3 Changing the mapping The mapping can be reset at any time during a GPlates session To reset the mapping for a feature collection 1 Open the Manage Feature Collections dialog CtrHM Manage Feature Collections Manage the feature collections which are loaded in the application File Name File Format In Use Actions 1 WorldO shp ESRI shapefile W a a Open File Save All 2 Select the File Properties icon A for the file whose mapping you want to change 3 The Re map Shapefile Attributes dialog will appear this behaves in the same way as the Map Shapefile Attributes dialog described above E Re map Shapefile Attributes Associate shapefile attributes with GPlates model properties Filename worldo shp Model property Shapefile attribute Plate ID PLATEID1 Feature Type TYPE Begin FROMAGE End TOAGE Name lt none gt Description DESCR E 4 When you have selected the fields for your mapping click OK Re mapping the shapefile attributes will update the shp gplates xml file
74. lect the centre point of the circle by entering coordinates or generate the data based on the reconstruction tree 5 4 3 Show Point Line Polygon Multipoint Features Selecting these options will prevent feature geometries of those types from being drawn on the globe 5 4 4 Show Arrow Decorations When a Velocity layer is active this option can be used to control the display of the velocity arrows 5 4 5 Configure Text Overlay GPlates can display the current reconstruction time within the globe area Selecting this menu item opens the Configure Text Overlay dialog configure Text Overlay Z Enable Text Overlay Text f Ma f will be substituted for the current reconstruction time Font Comic Sans MS 72pt Draw shadow Colour E Anchor Top Left v Horizontal offset 20 A Vertical offset 20 cancel SOK You can choose what text should be displayed using sf as a placeholder for the reconstruction time The text can be displayed in any of the four corners of the view 5 4 6 Configure Graticules With this menu item the graticule spacing can be configured to use a different grid spacing than the default 30 degrees The colour can also be changed if better contrast with a background raster is needed configure Graticules Graticule Properties Latitude delta 30 000 is Longitude delta 30 000 R Colour _ cancel SOK 6 Layers 6 1 Introduction
75. lick in the Lon to start entering new coordinates Type in a lon value press TAB type in a lat value press TAB to move to the button press SPACE to activate that button The new coordinate line will be added to the table and GPlates will prepare to receive the next line of input e Selecting a property from the table and selecting Delete will delete the property from the feature Feature Properces Property gpmi reconstructionPlateld Edit Polyline Valid geometry Append points Lon 0 0000 Lat 0 0000 Add Property Delete Property 9 2 6 Adding a Feature Property By clicking on Add Property in the Feature Properties window a new dialog will appear where you can select the Name Type and Value of a property In most cases you will only need to select the name of the property you wish to add the type of that property will be filled in automatically for you Add Property gpml errorBounds gpml foldAnnotation Add X gpml isActive gpml motion gml name gpml oldPlatesHeader gpml outlineof gpmi polarityChronid gpmi polarityChronOffset In the image above the user has clicked on the down arrow of the combo box and is selecting the gpml leftPlate property This property is used to annotate which regions are on either side of features such as a mid ocean ridge Add Property Name gpml leftPlate 7 Type gpmi plateld Add gpmi plateld Plate ID 307 H With the property name cho
76. lygons in paleo coordinates Export relative total rotation data Relative Total Rotation Equivalent Total Rotation CSV Export equivalent total rotation data Equivalent Stage Rotation CSV Export equivalent stage 1 My rotation data Raster bmp jpg jpeg png ppm tiffxbm xpm Export an image according to the current View settings Flowlines GMT Shapefiles Export flowlines Motion Paths GMT Shapefiles Export motion tracks 8 5 File name template The Filename field is used as a template value that GPlates will use to name your exported files and ensure that each Export snapshot gets assigned a unique name Special Placeholder tokens can be used in this text entry box that GPlates will substitute for different values according to what is being exported and at what time n the number index 1 of the frame will lie in the inclusive range 1 N and will be padded to the width of the decimal integer representation of N u the index of the frame will lie in the inclusive range 0 N 1 and will be padded to the width of the decimal integer representation of N 1 the reconstruction time instant of the frame in printf style f format d the reconstruction time instant of the frame rounded to the closest integer in printf style 8 d format P placeholder string will get replaced for each type of export 9 Interacting With Features This chapter provides a guide to interacting with the geologic
77. n lat time Example of an exported flowline GMT file gt reconstructionTime 0 gt test flow points gpml gt Flowline lt identity gt GPlates a5e5b41c 089a 4d3f a877 b5cc0088f43f lt identity gt lt revision gt GPlates 550e75b5 5d27 4146 b83d 93ccfa3be165 lt revision gt gt Left plate 802 gt Right plate 801 gt Times Og ply 15 20 25 30 35740 45 730 gt Seed point Lat 50 3407 Lon 139 229 gt Left plate flowline 139 2250 00 50 340700 0 000000 139 197261 531 897165 5 000000 1395325022 S3e017310 10 000000 139 565701 A 693 181 15 000000 139 856508 Soae97087 6 20 000000 140 163463 6 330579 25 000000 140 449153 589 839273 30000000 140 746852 60 218992 35 000000 141 049859 61 184592 40 000000 141 374462 61 686198 45 000000 141 655807 62 007476 50 000000 14 Total Reconstruction Pole Manipulation This chapter describes how to manipulate the reconstruction pole hierarchy using the Modify Reconstruction Poles tool 14 1 Modify Reconstruction Poles Tool Found on the Tool Palette the Modify Reconstruction Poles Tool is used to interactively modify the reconstruction poles for a given plate ID a Reconstruction Drag or Shift drag Ca current geometry to modify its reconstruction Pole pole ctrl drag to re orient the globe by holding down ctr1 14 1 1 Choosing a Plate ID to move To select a Plate ID to move the Plate needs to be in the field of view and the reconstruction
78. n use Add and Remove buttons to edit the table The Target directory specifies which directory all the files will be created in Users can use the button on the right to select directory increment that is not an exact multiple of the range of your animation For example creating an animation between 18 Ma and 0 Ma in increments of 5 M This range leaves a 3 million year gap at the end which does not fit neatly into the supplied 18 0 range Checking the Finish exactly on end time option ensures that GPlates will still write this final shorter frame AO The Finish exactly on end time checkbox is important if you are creating an animation with a time 8 2 6 Export The Export group is used to start and stop the export and provide progress information during the export process Click Begin to commence the export and begin creating files If you have specified a large range this may take some time The Abort button is provided in the event that users wishes to terminate the export sequence early In Export single Snapshot mode users can not abort 8 3 Add Export dialog When choosing the Add button to add a new export item to the table the Add Export dialog is shown to allow the selection of export type format and filename Configuration Select data to export Colat lon Mesh Velocities Resolved Topologies Relative Total Rotation Equivalent Total Rotation Equivalent Stage Rotation Raster Flowlines Motion Paths
79. nchored Plate ID Ctri D View Total Reconstruction Poles Ctri P 2 LO Assign Plate IDs bml unclassifiedGeometry ASSIGN Flate bm unclassifiedGeometry Generate Mesh Caps S Feature collection PresentDay_Isochrons_20 amp a View 3D Globe v 141 lat 36 93 lon 38 5 Mouse lat 79 16 lon 132 71 amp Clicked Topology Sections Feature type Plate ID i Name 14 gpml lsochron 7 CENTRAL NORTH ATLANTIC NORTHWEST AFRICA NORTH A K gt The Reconstruction Menu provides access to the following tools vee o p o memos n Sovanna brae someon Ss potatoe neno samostane ens peot mente ron perene Seeing neh Play Animation Opens the Export Dialog for exporing aspects of the reconstruction to files Specify Anchored Plate ID Specify the anchored plate in the plate hierarchy View Total Reconstruction Poles Pop up the Total Reconstruction Poles dialog Export Configure Animation Pop up the Configure Animation dialog to control the animation parameters Assign Plate IDs Using a set of plate polygons assign reconstruction plate IDs to features lacking them Generate Mesh Caps Automatically generate mesh caps suitable for sampling and exporting plate velocities 7 3 1 Reconstruct to Time When this menu item is invoked it will activate the Time field in the Main Window which is used to specify the current
80. ndicular to each other in latitude longitude space then you Il have a rotation otherwise you ll have a skew The default latitude longitude aligned bounds can be thought of as a non rotated non skewed image For a more detailed explanation of these parameters see the Wikipedia article on ESRI world files Currently GPlates does not perform datum conversions or image map projections So the latitude longitude Pre coordinates generated by the georeferencing transform that determine the positioning of the raster on the globe do not go through a further datum transformation or map projection Next you will asked if you want to save the raster to an existing or new feature collection Feature Collection Create a new feature collection to contain the raster Save New Feature Collection Save the new feature collection after click Finish GPlates will save the raster metadata in a GPML file in the same directory as the original raster files To reload the raster you can open this GPML file lt Back Finish Cancel Raster images currently do not display while using map projections other than the 3D Globe 3 3 Time Dependent Raster Sets 3 3 1 What is a time dependent raster set GPlates has the facility to display time dependent raster images that is raster images whose pixels change according to the reconstruction time In reality what GPlates is displaying is a time sequence of
81. new connection Polygon features Add new connection Age grid feature Add new connection Raster options Band band a Palette Default Palette mm gt Use Default Advanced options Disable layer The visibility icon determines whether the raster is drawn in the globe and map views The Input channels section has three types of input e Reconstruction tree is zero or one Reconstruction Tree layer This input layer provides the rotation hierarchy that enables GPlates to reconstruct the static polygon features in the Polygon features input channel If there is no Reconstruction Tree layer connected then the default Reconstruction Tree layer is used see the section on Reconstruction Tree Layer for more details on the default Reconstruction Tree e Polygon features is zero one or more feature collections containing static polygon features the static meaning the polygon shapes don t change These features should contain polygon geometry and should contain a reconstruction plate ID property on each polygon feature If there are no polygon features then the raster is not reconstructed e Age grid feature is zero or one Age Grid layer Despite the input channel name mentioning the word feature this is actually another layer Each pixel of the age grid raster is a floating point value representing the age of present day oceanic crust Also this raster must have been imported into GPlates using the age raster
82. ng the existing GPML file or e continue with the import process this means the existing GPML file will get overwritten if the you later decide to save the file or e cancel the import process and not load anything Import Raster as the raster file that you selected Do you wish to open this Y There is a GPML file bathy 450dpi gpml in the same directory existing GPML file instead of importing the raster file Cancel No of Yes Next you will be asked to enter the raster band name import Raster Raster Band Names Assign unique names to the bands in the raster Band Name 1 band_1 v Q Tip Use age as the band name if the band is an age grid Next gt Cancel The two default choices are band_ and age You can also type a new band name that describes the purpose or category of data contained in the raster This is useful when you need to identify a specific raster band in the Raster options of the raster layer for example to change the raster colour palette Currently the import process does not support importing of multi band rasters so there s only one raster band per raster If you are loading an age grid a floating point raster where each pixel represents the age of the crust covered by the pixel you have two options for the raster band name e Use the age band name if you are planning to reconstruct a raster with the assistance of an age grid the age grid isn t required
83. ng the plate by holding down Ctrl The Task Panel will display information about the reconstruction pole Reconstruction Pole Moving plate Constraints O Constrain Latitude Display O Highlight children Adjustment rotation This rotation will be applied to the reconstruction pole Latitude 65 28 Longitude 41 42 Angle 0 68 Reset Apply Constrain Latitude Ticking this option will ensure that any interactive dragging keeps the latitude unchanged Highlight Children Ticking this option will also highlight any plates that would be affected as a result of moving the selected plate due to the current rotation model 14 1 3 Committing Changes to a Reconstruction Pole To commit changes to a reconstruction pole simply click Apply and a new window will open up asking the user to 1 Choose a pole sequence 2 Verify new relative pole Apply Reconstruction Pole Adjustment Step 1 Choose pole sequence Step 2 Verify new relative pole Moving plate Original reconstruction pole 503 Latitude 26 10 5 Longitude 23 10 Current reconstruction time Ma Angle 1 95 Adjustment rel fixed plate Pole sequence z z z Latitude 57 27 Fixed Moving Begin End Longitude 158 44 Angle 5 17 New reconstruction pole Latitude 37 56 Longitude 23 26 Note Sequence cross overs are not yet Angle 5 73 automatically synchronised Step 3 Specify time for
84. nt Session functionality If the files you currently have open have changes made to them the act of opening a new session will replace them and GPlates will warn you about this in the same way 5 Controlling The View This chapter provides an overview of how to manipulate the view of the globe and any displayed data or features 5 1 View Menu The View Menu enables the user to manipulate the globe and includes the following options O GPlates File Edit Reconstruction Layers Tools Palaeomagnetism Help ma Full Screen F11 nq 44 a Current Feature 8 v Show Bottom Panel pes Ss Set Projection a gpml Isochron Camera Location Name CENTRAL NORTH ATLANTI YX Camera Zoom Rotate Anti clockwise Plate ID OoOo an Reset Orientation lt i 714 Gy i valid time from 139 6 to 399 AI Clicked geometry pml unclassifiedGeometry SS Feature collection PresentDay_Isochrons_20 CVE amp me BD Ca Man Mouse lat 51 63 lon 9 57 View 3DGlobe v 141 lat 1 21 lon 1 12 amp Clicked Topology Sections oy Feature type Plate ID Name T gpml Isochron 714 CENTRAL NORTH ATLANTIC NORTHWEST AFRICA NORTH w i _ Ka i gt Pr Full Screen Makes the GPlates Main Window fill the entire screen and hides most of the user interface elements such as the Tool
85. ny program state such as files loaded prior to selecting New Window is not transferred across to the new instance This feature is useful mainly for Mac OS X where it is not possible to run multiple instances of the same application from the Finder e Open Feature Collection e Open Recent Session e Import Raster e Import Time dependent Raster e Manage Feature Collections e View Read Errors e View Total Reconstruction Sequences e View Shapfile Attributes e Quit 2 5 2 Edit e Undo e Redo e Query Feature e Edit Feature e Copy Geometry to Digitise Tool e Clone Feature e Delete Feature Deletes the currently chosen feature and removes it from the feature collection that contained it Note that the feature collection is marked as modified but is not automatically saved to file see the Loading And Saving chapter e Clear Selection 2 5 3 View e Full Screen e Show Bottom Panel e Set Projection e Camera Location o Set Location o Move Up o Move Down o Move Left o Move Right e Camera Rotation o Rotate Clockwise o Rotate Anti clockwise o Reset Orientation e Camera Zoom o Set Zoom o Zoom In o Zoom Out o Reset Zoom 2 5 4 Reconstruction e Reconstruct to Time Step Backward One Frame Step Forward One Frame Reset Animation Play Animation Configure Animation Export Specify Anchored Plate ID View Total Reconstruction Poles Assign Plate IDs Generate Mesh Caps 2 5 5 Layers Show Layers Man
86. o 90 degrees and positions the image accordingly For regional rasters a surface extent of any longitude and latitude range for the raster can be specified enabling rasters of a smaller size to be correctly sized and positioned The default georeferencing covers the whole globe You can edit the georeferencing directly using latitude longitude aligned bounds or you can use the advanced option to specify an arbitrary affine transform import Time Dependent Raster Georeferencing Specify the location of the raster using lat lon bounds or an affine transformation 5 Top Left x coordinate 180 0000 x component of pixel width 0 4993 x component of pixel height 0 0000 I lt gt R gt R Top left y coordinate 90 0000 y component of pixel width 0 0000 y component of pixel height 0 5014 Show affine transform parameters advanced amp Use Global Extents gt K gt E lt Back Next gt Cancel The advanced option is enabled by ticking the Show affine transform parameters advanced check box With these advanced options you can also rotate or skew your raster The affine transform is defined as x and y components of pixel width and height and effectively determine the direction in latitude longitude space that the horizontal and vertical axes of the raster image will map to when positioned on the globe If the horizontal and vertical raster image directions are orthogonal perpe
87. ocity arrows are drawn in the globe and map views And the visibility icon of the Reconstructed Geometries layer determines whether the set of static points at which velocities are calculated are drawn W 129 mesh 10 Calculated Velocity Fields Reconstructed Geometries The Input channels section has three types of input e Mesh point Features is one or more feature collections containing features of type gpml MeshNode representing the set of static point locations at which to calculate velocity Reconstruction tree is zero or one Reconstruction Tree The Reconstruction Tree layer is used to calculate velocities Note that this should actually be the rotation tree used by the Resolved Topological Closed Plate Boundaries layer the one connected on the Source Features input channel This will be fixed in the next release e Source Features is one or more layers of type Resolved Topological Closed Plate Boundaries that generates the topological closed plate polygons that the velocities are calculated in haa The Source Features input channel must be connected to a layer of type Resolved Topological Closed Plate Boundaries and not a feature collection When a Calculated Velocity Fields layer is automatically created when the appropriate feature collection is rete loaded GPlates will search for all Resolved Topological Closed Plate Boundaries layers and connect their output to the input of the new Calculated Velocity Fi
88. ol_ice_low Reconstructed Raster In this example the raster layers are at the bottom and hence are drawn underneath the other layers And the user has selected only one raster to be visible the visibility icon is on for only one raster layer hal The layer position of Reconstruction Tree and Age Grid layers is not important since they produce no visible output Since there is currently no transparency slider on each layer the raster layers will be opaque they will obscure any layers below them So usually layers containing vector geometries will need to be drawn on top of any raster layers A few cases where a raster layer doesn t opaquely cover the entire globe are e Regional non global rasters only the region covered by the raster is opaque e Raster images containing transparent regions layers underneath will show through see the Data File Types chapter on raster image formats that support transparency e Reconstructed rasters progressively cover less area on the globe as you reconstruct back in time even if the raster image is global and has no transparent regions 6 5 Creating layers There are two ways in which a layer can be created Either automatically by GPlates when the user loads a feature collection or explicitly when the user creates a new layer 6 5 1 Automatically created layers When you load a feature collection usually one or more layers are created Loading these feature collections
89. ollections some possibly for temporary work which have not yet been named 4 4 File Errors 4 4 1 Introduction File read errors may occur when attempting to load data from file or some other data source such as a database GPlates developers have done their best to notify the user of the specifics of the error so corrections can be made 4 4 2 Error Categories It is anticipated that file input errors may fall into four categories 1 Warning 2 Recoverable error 3 Terminating error 4 Failure to begin When you load a file which causes warnings GPlates will display a warning icon A in the status bar You can click it to open the File Errors dialog for more information or click the View Read Errors entry on the File menu For more serious errors GPlates will open the dialog immediately on loading Warning e A warning is a notification of a problem generally a problem in the data which required GPlates to modify the data in order to rectify the situation e Examples of problems which might result in warnings include o Data which are being imported into GPlates which do not possess quite enough information for the needs of GPlates such as total reconstruction poles in PLATES4 rotation format files which have been commented out by changing their moving plate ID to 999 o An attribute field whose value is obviously incorrect but which is easy for GPlates to repair for instance when the Number Of Points field in a PLA
90. ollections dialog 4 5 2 Closing GPlates with unsaved changes If you close GPlates while there are still unsaved changes GPlates will ask you to confirm this action indicating which files have been modified and allowing you to select one of three actions to resolve the situation GPlates is closing The following feature collections have unsaved changes Coastlines _20091014 gpml Global _EarthByte_GPlates PresentDay_ PlatePolygons_20100826 gpml New Feature Collection iS Discard changes 6 Don t close ql Save all modified feature collections Discard changes 1 No files will be saved Any changes made since you last saved the file will not be kept 2 GPlates will close Don t close 1 GPlates will not close 2 This gives you an opportunity to go back and manually save the files you wish to keep and discard the rest Save all modified feature collections 1 GPlates will save every file that has been modified but not yet saved 2 In the event of a new feature collection which has not yet been given a file name you will be prompted to give each one a name using the standard save dialog However this may lead to ambiguity about which feature collection is being saved and it is advised to use the Don t Close option to carefully examine the situation 3 Ifall files were saved successfully GPlates will close The Unsaved Changes dialog may also be triggered when using the Open Rece
91. ometries it does not have the visibility icon to enable disable visibility The Input channels section has one type of input e Reconstruction features which is a list of input feature collections that contain rotation features More than one feature collection can be connected to the input of a Reconstruction Tree layer For example one feature collection may represent absolute rotations while another represents relative rotations When they are both input to the same Reconstruction Tree layer they are combined together inside the layer to form a single rotation hierarchy J If there are no rotation features in any input feature collections then no rotation hierarchy is generated which means nothing using this Reconstruction Tree layer will rotate or reconstruct Ifan input feature collection contains both rotation and non rotation features then the non rotation J features are simply ignored by the Reconstruction Tree layer since they cannot contribute to a rotation hierarchy The non rotation features will however have resulted in the automatic creation of a Reconstructed Geometries layer along with the automatic creation of this Reconstruction Tree layer So the non rotation features won t be ignored altogether they are just ignored by the Reconstruction Tree layer In turn the Reconstructed Geometries layer will ignore the rotation features The View Total Reconstruction Poles button displays a dialog to view a variety of informa
92. on disk 15 2 4 Viewing Shapefile attributes Shapefile attributes can be viewed in two ways e Foran entire feature collection e For individual features in a feature collection To view shapefile attributes for a feature collection 1 Go to the File Menu in the menu bar 2 Scroll down to View Shapefile Attributes 3 The Shapefile Attributes dialog will appear Shapefile Attributes v Feature Collection cntry98 shp 4A AC AC AF FIPS_CNTRY GMI_CNTRY ABW ATG ATG AFG DZA IS0_2DIGIT AW AG AG AF Dz IS0_3DIGIT ABW ATG ATG AFG DZA CNTRY_NAME Aruba Antigua and Barbuda Antigua and Barbuda Afghanistan Algeria Azerbaijan Azerbaijan Azerbaijan Azerbaijan Azerbaijan Albania Armenia SOVEREIGN Netherlands Antigua and Barbuda Antigua and Barbuda Afghanistan Algeria Azerbaijan Azerbaijan Azerbaijan Azerbaijan Azerbaijan Albania Armenia Pol 67074 65212 65212 17250 27459 54575t 54876t 54876 548 76 34169 33772 The shapefile attribute field names are displayed at the top of each column Each row of the table corresponds to a single feature in the feature collection and displays the attribute values for that feature If there is more than one shapefile feature collection loaded you can use Feature Collection drop down box at the top of the dialog to select the feature collection whos
93. ore feature collections containing topological closed plate polygon features These are features topologically reference regular features and form a continuously closing dynamic plate polygon from them through geological time e Reconstruction tree is zero or one Reconstruction Tree layer The Reconstruction Tree layer is not currently used but must match that used by the Reconstructed Geometries layer that contains the regular features referenced by the topological polygon features The regular features that make up the boundaries of each topological plate polygon are reconstructed in another layer a Reconstructed Geometries layer Currently the user does not need to make a connection to the Reconstructed Geometries layer although this will probably change in the next release since it will then allow more than one global topological plate polygon set to be loaded at the same time haa If the Reconstructed Geometries layer containing the regular features referenced by the topological polygon features uses a different Reconstruction Tree layer then no dynamic plate polygons are generated 6 6 6 Calculated Velocity Fields Layer This layer calculates plate velocities at a set of static locations Here static means non rotating the points do not move across the globe as the reconstruction time changes The velocities are calculated by determining which topological closed plate polygon contains each static point location Then the finite ro
94. osing the Export item It is used to configure what aspects of the data you want export what time range you want to export over and the file names and formats you want to use The Export process can work in two different modes Exporting a Time Sequence of snapshots or just exporting a Single Snapshot of data The controls are divided into three groups Range or Time for a single snapshot Options and Export 8 2 1 Export Time Sequence of Snapshots Given a time range export a series of files Each file contains data at a particular time point To activate the controls for exporting a time sequence choose the Export Time Sequences of Snapshots option at the top of the dialog gt Export Export Time Sequences of Snapshots Export Single Snapshot Range Animate from 140 00 A Ma Use Main Window to 0 00 Ma Use Main Window with an increment of 1 00 A My per frame Reverse the Animation by swapping the start and end times Options At each time step GPlates will create the following files Export Item Vv Format Filename Projected Geometries SVG svg snapshot_ u_ 0 2f svg Reconstructed Geometries GMT xy reconstructed_ u_ 0 2f xy Add Remove Target directory home jclark projects gplates 1 0 release sl Finish exactly on end time Export 140 00 Ma 0 141 0 Ready to export 8 2 2 Export single Snapshot Export data or image at a single s
95. pecific time To activate the controls for a one off snapshot click the Export Single Snapshot option at the top of the dialog O Export Time Sequences of Snapshots Export Single Snapshot Time Time 0 00 Ma Use Main Window Options GPlates will create the following files Export Item Format Filename Raster Portable Network Graphics png raster_ 0 2f png Add a Remove Target directory home jclark projects gplates 1 0 release ba Export 0 Ready to export f Export Close 8 2 3 Range When using Export Time Sequence of Snapshots the Range group of controls specifies the time range that the Export will cover For convenience these controls are linked to the Animation system and affect the same time range that you see with the Time Slider and Configure Animation dialog this way you can see a preview of what will be exported The Use Main Window buttons are a convenient way of quickly entering the time that the main window is currently viewing The Reverse the Animation button can swap the start and end time 8 2 4 Time The Time group is used with Export Single Snapshot to specify a time point 8 2 5 Options The Option group specifies the items which users want to export and the directory to store output files A table shows what files will be created at each time along with the substitution pattern that will be used to create each unique file name Users ca
96. plus an enumeration of each coordinate The Present Day column lists the coordinates of the geometry as it appears in the present i e 0 Ma The Reconstructed column lists the coordinates of the geometry as they appear on screen at the current view time which for convenience is displayed at the bottom of the dialog 9 2 8 if Copy Geometry to Digitise Tool Makes a copy of the geometry of the currently chosen feature if any has been selected and transfers the copied geometry to the appropriate digitisation tool WV Polyline Geometry tool for polyline geometry e Point Geometries tool for point or multi point geometry B You can then create a new feature from within the digitisation tool or if you are not ready to create a new feature yet you can further digitise the geometry to add lines or points or switch to a different geometry editing tool such as the Move Vertex Tool to make adjustments 9 2 9 d Clone Feature Makes a copy of the entire feature the currently chosen feature if any has been selected This differs from the Copy Geometry to Digitise Tool in that not only is the geometry of the feature copied but also all other properties of the feature are copied Polygon Geometry tool for polygon geometry This ability is useful when you want to create a new feature that has the same geometry as another feature but you want the feature type to be different or you want a new feature that has different properties b
97. presenting the plates on either side of the flowline and times of appearance and disappearance Flowlines will only be generated between the feature s time of appearance and time of disappearance Geometry Property Which property best indicates the gpml seedPoints geometry s purpose Other Properties Reconstruction Method Half Stage Rotation Right Plate ID 802 2 LeftPlate ID 801 Begin time of appearance Ma Distant Past End time of disappearance 0 00 Ma V Distant Future Name 802 801 flowline Create and Save Create Next select how GPlates should interpret your chosen point geometries as spreading centres as left end points or as right end points of flowlines and provide the times between which the half stage poles are calculated Custom properties Geometries Interpret provided geometries as Spreading centre s Left plate end point s Right plate end point s Actions EYE IC Insert single time Time 0 00 E Insert multiple times From 100 00 to 0 00 E in steps of 10 00 Finally assign your new flowline feature to a feature collection Create Feature Feature Collection Choose a feature collection for the new feature C SampleData DataBundleForNovices Global_EarthByte_GPlates_Coastlines_20091 C SampleData DataBundleForNovices Global_EarthByte_GPlates_Rotation_2009101 lt Create a new feature collection gt
98. pressed as the combination of a fixed plate id a moving plate id a point in time and a finite rotation Reconstructions are defined in a relative fashion A single total reconstruction pole defines the motion of one plate id the moving plate id relative to another the fixed plate id at a specific moment in geological time A sequence of total reconstruction poles is needed in order to fully model the motion of one particular plate across the surface of the globe throughout time 10 1 4 Anchored Plate ID A sequence of total reconstruction poles is used to model the motion of a single plate across the surface of the globe The total reconstruction poles describe the relative motion between each plate but ultimately this motion has to be traced back to a single plate ID which is considered anchored GPlates calls this the Anchored Plate ID Generally this plate ID corresponds to an absolute reference frame such as a hotspot paleomagnetic or mantle reference frame The convention is to assign the anchored plate ID to 000 but GPlates allows any plate ID to be used as the anchored plate ID 10 1 5 The Rotation Hierarchy To create the model of global plate rotations that is used in GPlates total reconstruction poles are arranged to form a hierarchy or tree like structure At the top of the hierarchy is the anchored plate ID Successive plate IDs are further down the chain linked by total reconstruction poles To calculate the absolu
99. r than a feature collection containing rotation features is because a rotation hierarchy needs to be generated from the rotation features themselves and so this process is performed by a different type of layer the Reconstruction Tree layer See the More on Reconstructions chapter for more information about rotation hierarchies The output of most types of layers exceptions include Reconstruction Tree layers and Age Grid layers contain geometries and hence can be visualised in the globe and map views 6 4 The Layers dialog The Layers dialog is usually displayed automatically when you first load a feature collection To show hide the dialog select the Show Layers menu item in the Layers menu or use the CTRL L shortcut key Tools Palaeomagnetism Help B Show Layers Ctrl L Manage Colouring Manage Small Circles 4 14 S S STS Show Point Features Show Line Features Show Polygon Features Show Multipoint Features Show Arrow Decorations Show Text Configure Text Overlay Configure Graticules Choose Background Colour Show Stars The Layers dialog contains all layers and is the central place to configure layer visibility draw order input connections and layer specific options Global_EarthByte_GPlates_Rotation_20100927 Reconstruction Tree w Global_EarthByte_GPlates_PresentDay_Ridges_20100927 Reconstructed Geometries Global_EarthByte_GPlates_PresentDay_Isochrons_20100927 Recons
100. reconstruction time The user can type a new reconstruction time or increase or decrease the value using the Up and Down arrow keys or the mouse scroll wheel before pressing the Enter key to execute the reconstruction The current frame of the animation always corresponds to the reconstruction time Changing the reconstruction time will simultaneously change the current frame of the animation If the specified time is outside the current range of the animation the range will be extended 7 3 2 Step Forward One Frame This button is used to change the current reconstruction time forward that you are viewing in small steps 7 3 3 Step Backward One Frame This button is used to change the current reconstruction time backward that you are viewing in small steps 7 3 4 Specify Anchored Plate ID This item is used to choose the anchored plate ID of the plate hierarchy It will be described in the chapter More On Reconstructions 7 3 5 View Total Reconstruction Poles When this item is activated the Total Reconstruction Poles dialog will appear enabling the user to view a variety of information about the reconstruction poles and the plate hierarchy at the current reconstruction time This dialog will be described in the chapter More On Reconstructions T ta ReconstrucHon Poles Total reconstruction poles generated at Ma with anchored plate ID fo Relative Rotations Equivalent Rotations rel Anchored Plate Reconstruction Tree Plate
101. rent reconstruction time will be rendered This is most noticeable near mid ocean ridges where long thin polygons adjacent the ridge appear disappear as you go fowards backwards in time to simulate accretion or crust material at the mid ocean ridge This is also the reason why a reconstructed global raster covers the entire globe at present day but covers a progressively smaller area of the globe as you reconstruct back in time polygons with lower plate IDs This is because higher plate IDs tend to be further from the anchor plate in the plate circuit although this is not necessarily the case Currently polygons and their associated cookie cut raster pieces with higher plate IDs are drawn on top of This configuration is obtained by connecting the Polygon features input channel to a feature collection containing static polygons and optionally connecting the Reconstruction tree input channel to a Reconstruction Tree layer otherwise the default Reconstruction Tree layer is used Input channels Raster feature color_etopol_ice low gpml Add new connection Reconstruction tree Add new connection Polygon features Global_EarthByte_GPlates PresentD StaticPlatePolygons_20101209 gpml Add new connection Age grid feature Add new connection The resulting reconstructed raster Time 34 00 gt me View 3D Globe 112 gt lat 0 71 lon 12 48 Mouse at 40 13 lon not
102. rol for the camera zoom level Camera Coordinate An information field which indicates the current globe position of the Globe View camera Mouse Coordinate An information field which indicates the current globe position of the mouse cursor 5 3 Tool Palette The first two tools in the Tool Palette control your view of the GPlates globe or map The Tool Palette includes camera positioning tools feature selection tools and drawing tools A tool is activated by clicking on it only one tool can be active at any time The Current Feature Panel will change to reflect the current tool that is activated Click to zoom in Shift tclick to zoom out Ctrl drag to re orient Zoom In Z 5 4 Layers Menu Drag to re orient the globe Shift drag to rotate the globe The Layers Menu enables further customisation of data presentation and allows access to the Layers Window The Layers functionality is described in depth in the Layers chapter Other items available in this menu are Manage Colouring Manage Small Circles Show Point Features Show Line Features Show Polygon Features Show Multipoint Features Show Arrow Decorations Show Text Configure Text Overlay Configure Graticules Choose Background Colour y Show Stars 5 4 1 Manage Colouring This operation opens the Manage Colouring dialog which allows the user to customise how feature geometries are coloured gt Manage Colouring Feature Collection
103. rrent file with its current name e Will overwrite previous contents of the file This is useful when you have modified your file and are happy to save these changes A Do not edit the file in two separate programs simultaneously e g GPlates and a text editor W Save As e Saves the current file with a new name Will leave the previous file intact Will load the new file in place of the old file e Gives you the opportunity to change the file format This is useful when you want to edit a copy of a file without changing the original r Save a Copy e Saves a copy of the current file with a new name e Will leave the previous file intact e Will not replace or unload the current file e Gives you the opportunity to change the file format This is useful for making backups of your work as you go 4 3 2 Saving all modified files If a file has been modified in GPlates it will appear with a red background colour to highlight it As a convenient shortcut for saving all your changes in one go the Manage Feature Collections dialog has a Save All button Clicking the Save All button will save all files that 1 Have been modified in GPlates since they were last loaded saved 2 Have a file name haa The Save All button does not save newly created feature collections highlighted in orange which have e not been saved with a file name yet This is to avoid ambiguity in case you have created many new feature c
104. rthByte_GPlates_PresentDay_StaticPlatePolygons_20100927 gpml 2 Global_EarthByte_GPlates_Coastlines_20100927 gpml 3 Global_EarthByte_GPlates_Rotation_20100927 rot Features to Partition Specify features to be partitioned File Name 1 Global_EarthByte_GPlates_PresentDay_StaticPlatePolygons_20100927 gpml 2 Global_EarthByte_GPlates_Coastlines_20100927 gpml 3 Global_EarthByte_GPlates_Rotation_20100927 rot Here the user can specify some options J Assign Plate IDs res Reconstruction Time Select the reconstruction time representing the geometry in the feature collections Present day Current reconstruction time 0 Ma Specify reconstruction time 0 00 Ma Feature Partitioning Specify how features should be partitioned C Copy feature properties from the polygon that most overlaps a feature C Copy feature properties from the polygon that most overlaps each geometry in a feature Partition cookie cut feature geometry into polygons and copy feature properties Feature Properties Specify the feature properties to copy from a polygon V Reconstruction plate ID Time of appearance and disappearance Next Specifying the reconstruction time Select the reconstruction time representing the geometry in the feature collections The three options for reconstruction time are e Present day the reconstruction time is 0Ma e Current reconstruction time the reconstruction time in the main window e Spec
105. s can generate and export flowlines 13 2 Creating flowlines To use flowlines in GPlates you need to create or load a flowline feature Flowline features can be created like other features with the digitisation tool See Creating New Features for more information on using the digitisation tool To create a flowline begin by selecting the Point Geometries icon from the Tool Palette af After choosing the Point Geometries tool select points on the globe which represent the flowline spreading centre or either of the flowline end points Later in the creation process you can instruct GPlates which sort of point you have chosen Once you are satisfied with the locations click the Create Feature button and select gpml Flowline as the desired feature type Point Geometries Flowlines can be created at any reconstruction time aml G p Feature Feature Type gpml ClosedPlateBoundary gpml Coastline gpml ComputationalMesh gpml ContinentalFragment gpml ContinentalRift gpml Craton gpml CrustalThickness gpml DynamicTopography gpml ExtendedContinentalCrust gpml Fault gpm Flowline gpml FoldPlane gpml FractureZone gpmil FractureZoneldentification gpml GeologicalLineation gpml GeologicalPlane gpmIl GlobalElevation gpml Gravimetry gpml HeatFlow gpml HotSpot gpmil HotSpottTrail gpmi InferredPaleoBoundary qpml IslandArc Previous Create and Save The next step is to allocate left and right plate ids re
106. s using the same plate ID move in unison when reconstructed back through time A plate ID is a non negative whole number Assigning specific meanings to specific plate IDs such as making plate ID 714 correspond to northwest Africa is up to the creator of the rotation file Plate IDs do not correspond to a physical tectonic plate although they may represent the motion of features which are on that physical plate Plate IDs can also be assigned to represent the motion of things on the same physical plate relative to one another for example the motion of an island arc caused by back arc spreading A subduction zone can be assigned one plate ID and its associated island arc can be assigned another plate ID The motion of both of these plate IDs can be anchored to a third plate ID representing the global motion of the physical plate underneath the subduction zone and island arc 10 1 2 Finite Rotations Euler s Displacement Theorem tells us that any displacement on the surface of the globe can be modelled as a rotation about some axis This combination of axis and angle is called a finite rotation Finite rotations are used by GPlates as the elementary building blocks of plate motion 10 1 3 Total Reconstruction Poles Total Reconstruction Poles tie finite rotations to plate motion A total reconstruction pole is a finite rotation which reconstructs a plate from its present day position to its position at some point in time in the past It is ex
107. se can be accessed via the Reconstruction menu J The Step Forwards one Frame Step Backwards one Frame buttons can be held down to move through time rapidly The forwards and backwards buttons apply relative to the current animation time Normally the present day 0 Ma is at the right hand side of the animation slider and the distant past is on the left hand side GPlates makes it possible for you to set a reverse animation where the start time is the present day or near past and the end time is in the distant future When an animation is set up this way the slider and buttons behave as consistently as possible your start time the present is on the left and your end time the distant past is on the right Using the Step Forwards one Frame button moves the slider to the right into the past and the Step Backwards one Frame button does the opposite as you would expect J The default settings for the Slider are a time range of 140Ma to present and a time increment per frame of 1 million years 7 3 Reconstruction Menu AECE File Edit View Layers Tools Palaeomagnetism Help 2R Reconstruct to Time sukad Current Feature l 44 Step Backward One Frame Gureiiicgm Type b gt Step Forward One Frame Ctri l a gpml Isochron Reset Animation Name Play Animation CENTRAL NORTH ATLANTI Configure Animation Plate ID FE Export 714 Valid time from 139 6 to 999 Clicked geometry A m Specify A
108. sen the lower section of the dialog presents the appropriate controls for entering the new value in this case a plate ID Press Enter or the OK button to confirm the addition of the new property al If the property you are adding is not appropriate for the type of feature then a warning message is displayed at the bottom of the Add Property dialog 9 2 7 Viewing Coordinates Feature Properties Feature Type gpm Fault Q Query Properties Edit Properties J View Coordinates gmi LineString gt 0 lat lon 1 lat lon 2 lat lon 3 lat lon 4 lat lon 5 lat lon 6 lat lon 7 lat lon 8 lat lon 9 lat lon 10 lat lon 11 lat lon 42 9253 20 6391 42 925 20 674 42 9099 20 7124 42 86 20 7684 42 8116 20 8024 42 7286 20 87 42 659 20 9181 42 5967 20 9586 42 5787 20 9695 42 5501 20 9882 42 5122 21 0203 42 5073 21 0409 Present Day Reconstructed gml OrientableCurve 42 9253 20 6391 42 925 20 674 42 9099 20 7124 42 86 20 7684 42 8116 20 8024 42 7286 20 87 42 659 20 9181 42 5967 20 9586 42 5787 20 9695 42 5501 20 9882 42 5122 21 0203 42 5073 21 0409 Reconstructed relative to the anchored plate ID The View Coordinates dialog provides a tree view summarising the coordinates of every geometry in the feature The Property Name column lists the names and types of geometry
109. sub tabs one for the topology itself and the other for a feature intended to become a section of the topology 16 2 3 Topology Tab The Topology Tab shows a summary of the topology under edit Topology Tools Topology Section Name Plate Id Valid time from to Number of Sections Remove All Sections Apply Create When building a new topology the Name Plate Id and Valid Time displays will be blank these values will be set when finalizing the new topology When editing an existing topology these will display that the various property values of that topology feature The Remove All Sections button will delete all entries in Topology Sections Table and effectively clear the topology Use with caution this operation has no undo The Apply Create button is used to apply all edits to the current topology under the Edit Topology Tool or to finalise the creation process under the Build New Topology Tool 16 2 4 Section Tab Topology Tools Topology Section ba rs Ype Feature collect Add Focused Feature Remove Focused Feature The Section Tab shows the basic properties of the focused feature The Add Focused Feature button will insert the feature into the Topology Sections Table at the current Insertion Point See below for an explaination of the table and the insertion point 16 3 Topology Sections Table The Topology Sections Table holds an ordered
110. t For these pixels the polygon age is used instead of the pixel age So basically the pixel age is used only where it is valid E The per pixel age comparison test is currently performed on the graphics card where it is significantly faster Hence the cost to interactivity of age grids is small Changing the rotation model requires re generating the age grid this process is performed outside GPlates This configuration is obtained by connecting the Polygon features input channel to a feature collection containing static polygons and connecting the Age grid feature input channel to an age grid layer And optionally connecting the Reconstruction tree input channel to a Reconstruction Tree layer otherwise the default Reconstruction Tree layer is used Input channels Raster feature color_etopol_ice_low gpml Add new connection G Reconstruction tree Add new connection Polygon features Global_EarthByte_GPlates_ PresentD StaticPlatePolygons_20101209 gpml Add new connection Age grid feature bgegrid6m S s Add new connection The resulting reconstructed raster with the assistance of an age grid Time 34 00 ma View 3D Gobe 112 lat 0 71 lon 12 48 Mouse lat 54 37 lon note the absense of the thin gap along the mid ocean ridge between South America and Africa This is due to the per pixel age comparison as opposed to the per polygon age comparison
111. tain the data it has already read but will not be able to read any more data from the data source Failure to begin e A failure to begin has occurred when GPlates is not even able to start reading data from the data source e Examples of failures to begin might include o The file cannot be located on disk or opened for reading The database cannot be accessed no network connection could be established e In the event of a failure to begin GPlates will not be able to load any data from the data source File Errors There were 8 warnings e By Error By Line Warnings 8 a_data_file_with_errors pla PLATES line format B homes geo jboyden GPlates Code 2008 trunk a_data_file_with_errors pla 25 Unrecognized Data Type Code 8 Line 420 25 5 25 Unrecognized Data Type Code in the header 5 Because the Data Type Code was not known Unclassified Features will be created Line 10836 25 5 t Line 11186 25 5 Line 11271 25 5 Line 11306 25 5 q Line 11459 25 5 q Line 11550 25 5 Q Line 13997 25 5 4 5 Unsaved Changes 4 5 1 Introduction GPlates keeps track of any changes you make to files while they are loaded To remind you that some feature collections have on unsaved changes GPlates will display the icon in the status area Hover over the icon to see a list of modified files or click it to open the Manage Feature C
112. tains the VirtualGeomagneticPole s sample site point location For these features the above options are ignored Specifying which feature properties to copy This options allows the user to specify which feature properties are copied from the partitioning polygon feature to the feature to be partitioned Currently two feature property options are supported in the future this will be extended to support any feature property e Reconstruction plate ID the reconstruction plate ID property e Time of appearance and disappearance the time interval over which a feature exists These options are not mutually exclusive Both can be selected Depending on the number of features to be partitioned it can take a while to assign plate IDs and optionally partition the geometries Partitioning features es 12 The features to be partitioned have now been modified Manage the feature collections which are loaded in the application File Name File Format Actions ma ABHA 1 Global_EarthByte_GPlates_PresentDay_StaticPlatePolygons_2 Language LEN Global atv Ge Coastin ETT apm ae z 3 Global_EarthByte_GPlates_Rotation_20100927 rot PLATES4 rotation R A Currently if a feature to be partitioned contains polygon geometry and the Partition cookie cut feature geometry option is selected then the resulting partitioned geometry will be polylines instead of polygons This will be rectified in a future release 7 3 7 Generate
113. tation corresponding to that plate polygon s reconstruction plate ID is used to calculate the velocity at the static point location This type of layer is automatically created when a feature collection containing features of type gpml MeshNode is loaded These features contain multi point geometry that defines the set of static locations at which to calculate velocity An associated Reconstructed Geometries layer is also created to visualise the point locations The Calculated Velocity Fields layer visualises the velocities as arrows longer arrows represent larger velocities The velocity arrows are not drawn at every static point location Instead they are spaced apart so that they are minimum distance from each other on the screen on the computer monitor This so they can be distinguished visually even for very dense meshes i View 562 lat 2 67 lon 16 90 Mouse lat 13 47 lon Calculated Velocity Fields Options A Calculated Velocity Fields layer has the following configuration options i 129 mesh 10 Calculated Velocity Fields Input channels Mesh point Features 129 mesh 10 gpml Add new connection Reconstruction tree Caltech_Global_20101129 Add nevi id sur coh arts dd new connection Source Features Caltech_Global_20101129 Add new connection Advanced options Disable layer The visibility icon of the Calculated Velocity Fields layer determines whether the vel
114. te rotation of a plate ID of a plate with a given plate ID relative to the fixed reference defined by the anchored plate ID at a given time GPlates starts at that point in the hierarchy and works its way up to the top to the root of the tree 10 2 Specify Anchored Plate ID The Specify Anchored Plate ID command on the Reconstruction menu can be used to change which plate ID GPlates considers to be the globally fixed reference when performing reconstructions Enter a new plate ID to be the anchor in the dialog that pops up and GPlates will automatically rearrange the rotation hierarchy so that the specified plate ID is at the top f Specify Anchored Plate ID Fixed plate 701 L 10 3 Reconstruction Pole Dialog The Total Reconstruction Pole Dialog is accessed from the Reconstruction menu It contains four tables of information relevant to the current reconstruction time and the current anchored plate ID 10 3 1 Relative Rotations This table lists all the total reconstruction poles in terms of the relative motions between plates for the current reconstruction time T ta ReconstrucHon Poles Total reconstruction poles generated at Ma with anchored plate ID jos Relative Rotations Equivalent Rotations rel Anchored Plate Reconstruction Tree Plate Circuits to Anchored Plate Each rotation describes the motion of a plate relative to some other fixed plate late _tsttude tongtude ange Prea Piate
115. te the user s view of the globe Within a menu similar operations are grouped visually by horizontal lines or within sub menus In the View Menu below the Camera Location Camera Rotation and Camera Zoom controls are grouped into their own sub menus a OQ GPlates File Edit Reconstruction Layers Tools Palaeomagnetism Help _ FullScreen F11 i Current Feature aa K4 44 DD Show Bottom Panel asin S Npe Set Projection i gpml Isochron El Name Camera Location CENTRAL NORTH ATLANTI Camera Zoom Rotate Anti clockwise Plate ID s Reset Orientation hi 714 Valid time from 139 6 to 999 Clicked geometry zD 2O pml unclassifiedGeometry Feature collection SS PresentDay_Isochrons_20 CIEI amp Gy Pam Il View 3D Globe v 141 S lat 1 21 lon 1 12 Mouse lat 51 63 lon 9 57 amp Clicked Topology Sections Feature type Plate ID Name gpml Isochron 714 CENTRAL NORTH ATLANTIC NORTHWEST AFRICA NORTH lt l gt Some menu items use check boxes or tick marks to switch or choose operations For example Show Bottom Panel is activated by a small cross or tick that will be displayed next to the menu item when selected 2 4 Tool Palette The Tool Palette is used to control your view and interaction with the GPlates globe and maps You may recognise the concept of tools from graphics
116. the past which may be inferred from other data Geological geophysical and paleo geographic data may be attached to the simulated plates enabling a researcher to trace the motions and interactions of these data through time 1 2 2 The Goals of GPlates e to handle and visualise data in a variety of geometries and formats including raster data e to link plate kinematics to geodynamic models e to serve as an interactive client in a grid computing network e to facilitate the production of high quality paleo geographic maps 1 3 GPlates Development GPlates is developed by an international team of scientists professional software developers and post graduate students at e the EarthByte Project part of the AuScope National Collaborative Research Infrastructure Strategy NCRIS Program in the School of Geosciences at the University of Sydney under the direction of Prof Dietmar Miiller e the Division of Geological and Planetary Sciences at CalTech under the direction of Prof Michael Gurnis e the Centre for Geodynamics at the Norwegian Geological Survey NGU under the direction of Prof Trond Torsvik Collaborating scientists at the University of Sydney the Norwegian Geological Survey and CalTech have also been compiling sets of global data for plate boundaries continental oceanic crust boundaries plate rotations absolute reference frames and dynamic topography GPlates is free software also known as open source software lic
117. these points define the geometry feature you want to create You can still rotate the globe by holding down the ctr1 key After you have plotted the feature the latitude and longitude can be verified in the digitisation panel New Geometry Coordinates Lat Lon 15 3252 56 5342 19 5824 56 7360 21 4937 54 9192 22 6198 53 4930 23 6059 51 7523 23 9378 51 0205 26 0960 49 4509 26 9290 49 1772 29 1199 48 7987 30 7522 48 5530 33 8322 48 8658 35 3517 47 7963 36 1862 46 8353 37 2990 44 3444 37 4313 42 6557 37 8036 40 7850 l 38 2804 38 8894 Feature Create Feature Once you are satisfied with the new feature location click Create Feature button to select the type of feature you would like to create E g Isochron Fault Mid Ocean Ridge etc Greate Feature Feature type gpml AseismicRidge gpml BasicRockUnit gpml Basin gpml Bathymetry gpml ClosedContinentalBoundary gpml ClosedPlateBoundary gpml Coastline gpml ContinentalFragment gpml ContinentalRift gpml Craton gpml CrustalThickness gpml DynamicTopography gpml ExtendedContinentalCrust U gpml FoldPlane gpml FracturezZone gpml FracturezZoneldentification gpml GeologicalLineation gpml GeologicalPlane gpml GlobalElevation gpml Gravimetry Previous X Create Cancel 4 The next step is to assign a geometry to the feature as well as e Plate ID e A begin time for the feature e Anend time e A name To help
118. tion about the reconstruction poles and the plate hierarchy for that particular Reconstruction Tree layer at the current reconstruction time See the Reconstructions chapter for more information on that dialog Default Reconstruction Tree One fundamental difference between Reconstruction Tree layers and other types of layers is you can set a default Reconstruction Tree layer Only one Reconstruction Tree layer can be the default and you can tell which one is the default because it will have Default underneath the layer name Global_EarthByte_GPlates_Rotation_20100927 Default Reconstruction Tree You can set the default Reconstruction Tree layer using the Set as default reconstruction tree option under Advanced options ina Reconstruction Tree layer The option will be greyed out if the layer is already the default Advanced options Disable layer Set as default reconstruction tree becomes the new default Reconstruction Tree layer If you want your previous default Reconstruction Tree layer to remain as the default you will need to explicitly set it as the default after loading the new rotation file When a feature collection containing rotation features is loaded its associated Reconstruction Tree layer The default Reconstruction Tree layer is only applicable if another layer such as a Reconstructed Geometries layer requires a Reconstruction Tree input and has not explicitly connected one to its input If all layers with
119. to reconstruct a raster but it does make the reconstruction smoother or e Use any other band name if you want to visualise the age grid as you would any other raster for example if you wanted to apply a colour palette to map the floating point age pixels to RGB colours GPlates recognises the age band name and treats the imported raster as a special case The special handling results in the raster not being visible but conversely it does allow you to connect the layer associated with this imported age grid raster to a regular raster layer to assist in reconstructing it See the Layers chapter for more information on using an age grid raster in this way Next you will be asked to confirm the global georeferencing information or enter new georeferencing information to control where on the globe your raster should be positioned import Raster Georeferencing Specify the location of the raster using lat lon bounds or an affine transformation Top lat 90 0000 gt I Bottom lat 90 0000 Left lon 180 0000 lt gt lk gt ik Right lon 180 0000 O Show affine transform parameters advanced Use Global Extents lt Back Next gt Cancel GPlates is able to display global covering the whole globe and regional covering a user specified zone raster images GPlates assumes that a global image spans the longitude range of 180 degrees to 180 degrees and the latitude range of 90 t
120. tree Global_EarthByte_GPlates_Rotation_20100927 Add ne Note that in this example Add new connection is disabled and greyed out since only one Reconstruction Tree input connection is allowed You can still have multiple rotation feature collections as input to a Reconstruction Tree layer though 6 6 3 Reconstructed Raster Layer This layer can display a single raster feature containing a single raster image or a time dependent sequence of raster images in the following configurations e araster or time dependent raster sequence that is not reconstructed or e araster or time dependent raster sequence that is reconstructed using a set of static polygons or e araster or time dependent raster sequence that is reconstructed using a set of static polygons and an age grid view zoom As you zoom in higher resolutions versions of the original raster are progressively loaded and displayed until the resolution of the original raster is exceeded Rasters are displayed at the highest resolution available for the current monitor screen size and amount of haa Currently rasters are only displayed in the Globe view Displaying rasters in the map views will be available in a subsequent release Reconstructed Raster Options A Reconstructed Raster layer has the following configuration options W color_etopol _ice_low Reconstructed Raster Input channels Raster feature color_etopol_ice_low gpml Reconstruction tree Add
121. tron 35 00 Ma Name CENTRAL ATLANTIC AF RIQ Plate ID 701 Valid time from 47 9 to 999 Clicked geometry bmi unclassifiedGeometry Feature collection PresentDay_Isochrons_20 EEIE l view Rectangular vi 158 lat 0 00 lon 0 00 Mouse lat lon off map amp Clicked Topology Sections Feature type Plate ID Name gpml Isochron 701 CENTRAL ATLANTIC AFRICA SOUTH AMERICA ANOMALY 1 R i i a Ge a ha Y a 7 2 1 Slider Dorao Interface to interact with reconstruction animations in GPlates discussed in further detail below D Play Starts animation when pressed it changes to the pause button Di Pause Halts animation when pressed it changes to play button KK Reset Returns animation to the start time b gt Fast Forward Step forwards one frame in the animation 1 Rewind Step backwards one frame in the animation 7 2 2 Step Forwards One Frame Step Backwards One Frame Fast Forward and Rewind These buttons are used to change the current reconstruction time that you are viewing in small steps Pressing the buttons once or using their shortcut keys ct r1 1 for forwards ctr1 Shift 1 for backwards will adjust the reconstruction time by one frame The time interval between frames can be adjusted via the Animate Dialog or the Specify Time Increment dialog Both of the
122. tructed Geometries Global_EarthByte_GPlates_PresentDay_StaticPlatePolygons_20101209 Reconstructed Geometries Global_EarthByte_GPlates_PresentDay_COBs_20101209 Reconstructed Geometries Global_EarthByte_GPlates Coastlines_20101209 Reconstructed Geometries Caltech_Global_20101129 Default Reconstruction Tree Caltech_Global_20101129 Reconstructed Geometries Caltech_Global_20101129 Resolved Topological Closed Plate Boundaries W 129 mesh 10 Calculated Velocity Fields 129 mesh 10 Reconstructed Geometries agegrid_6m Age Grid DNSCO8GRA_6m Reconstructed Raster color_etopol_ice_low Reconstructed Raster The collapsed view of each layer in the dialog shows a layer name type and colour The type and colour are associated for example a green layer is always of type Reconstructed Geometries The layer name depends on how the layer was created see the Creating layers section for more details 6 4 1 Changing layer visibility The visibility of each layer can be individually disabled or enabled by clicking the icon to the left of the layer name Some types of layers such as the Reconstruction Tree layer and Age Grid layer do not have a visibility Fete icon This is because those layer types do not output geometries and hence there is nothing to visualise in the globe and map views Each layer contains a small black arrow that can be clicked on to expand the layer and show the input connections and
123. uctible features The ability to reconstruct raster images on the globe enables the user to visualise the movement of raster data as if it were cutout and attached to a set of polygons with the movement of the respective cutout raster pieces dictated by the movement of the individual polygons For more information on reconstructing rasters please see the More on Reconstructions chapter 3 2 2 Which image formats does GPlates understand GPlates reads images in a variety of formats which can be roughly categorised into two groups RGBA images These type of images have a Red Green Blue and optional Alpha value usually 8 bits each for each pixel in the image Some of the supported file formats include JPEG as known as JPG PNG TIFF GIF Formats like JPEG do not have transparency the Alpha value whereas other formats such as PNG support transparency When raster images containing transparent regions are drawn on top of other rasters or vector geometries the underlying rasters geometries will be visible through the transparent regions See the Layers chapter for more information on the visual ordering of rasters or more generally layers Some of these formats have inbuilt compression such as JPEG which result in smaller file sizes but can introduce compression artifacts depending on the compression quality Other formats such as BMP do not have compression and can be quite large Regardless of the file size the amount of memory used
124. ut same geometry Copy Geometry to Digitise Tool does not work on topological features such as Topological Closed Plate Polygon features The geometry of these features changes dynamically as the reconstruction time changes After this operation you will have two features which are identical except for their feature ID the uniqueness identifier The focused feature will now be the new cloned feature Since both features have the same geometry s they will be indistinguishable except for the fact that they have different feature IDs however the mouse click point will now reveal two features in the Clicked Geometry Table the original feature and the cloned feature Unlike Copy Geometry to Digitise Tool Clone Feature does work on topological features such as Topological Closed Plate Polygon features In this case the time dependent list of topological sections referenced by a Topological Closed Plate Polygon feature is just another property of that feature that gets copied like any other property 9 2 10 w Delete Feature Deletes the currently chosen feature and removes it from the feature collection that contained it The feature collection is marked as modified but is not automatically saved to file see the Loading And Saving chapter 10 More on Reconstructions 10 1 Theory 10 1 1 Plate IDs As discussed earlier in this documentation GPlates uses the concept of a Plate ID to ascribe tectonic motion to a feature All feature
125. you distinguish classify your feature Greace Feature Assign geometry to property Unclassified miscellaneous Which property best indicates the geometny s purpose Basic properties a atep ooo E Name Thrust fault between Serbo Macedonia and Rhodopes A In the final step of feature creation the feature is assigned to a feature collection All data files that are currently loaded in GPlates will be listed here as well as the lt New Feature Collection gt option Choosing any one of the existing feature collections and clicking Create will add the newly digitised feature to that collection and return the user to the GPlates main window Greate Feature Add feature to collection Choose the feature collection to which the new feature should be added export ul1 jclark gplates data earthbyte Global_EarthByte_20071217 export u1 jclark gplates data earthbyte Global_EarthByte_20071105 4 Ifthe lt New Feature Collection gt option is selected a new feature collection will be created to hold the new feature This feature collection will not yet have a name and is not associated with a file on disk Like all other feature collections the new one will be found in the Manage Feature Collections dialog 13 Flowlines 13 1 Introduction Flowlines represent the movement of material away from a spreading centre and are calculated based on half stage poles between two plates at specified time intervals GPlate

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