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tectonicwaters:2013:0628_graticules_for_plate_tectonic_reconstructions [2020/12/29 21:49] – ↷ Page moved and renamed from tectonicwaters:2020:1229_graticules_for_plate_tectonic_reconstructions to tectonicwaters:2013:0628_graticules_for_plate_tectonic_reconstructions christiantectonicwaters:2013:0628_graticules_for_plate_tectonic_reconstructions [2023/11/16 20:44] (current) – christian
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 ====== Graticules for plate tectonic reconstructions ====== ====== Graticules for plate tectonic reconstructions ======
 +
 +TLDR:
 +  * Downloadable graticule (''*.gpml'' file) for GPlates can be downloaded [[https://code.paleoearthlabs.org/gptools/raw/23ad783f7b5868180953b6f32ab9601e0b1164b55bfe6753526e5e578a8044d0?at=Graticule.gpml|here]]
 +  * Repository for the Python-based graticule creation is [[https://code.paleoearthlabs.org/gptools/doc/trunk/README.md|here]] or [[https://git.sr.ht/~chhei/gptools/|here]]
 +
 +
  
 Plate tectonic reconstructions require to have some present-day markers so that any person reading or looking at the results can correlate the paleo plate positions and continents with present day. Things did indeed look quite a bit different back then... Usually the present-day coastlines are used a such a marker, but [[http://dx.doi.org/10.1126/science.1151540|as sealevel has varied extensively over the geological history]], displaying an Early Cretaceous reconstruction at, say 110 Million years, with present-day shorelines might be a bit misleading.  Plate tectonic reconstructions require to have some present-day markers so that any person reading or looking at the results can correlate the paleo plate positions and continents with present day. Things did indeed look quite a bit different back then... Usually the present-day coastlines are used a such a marker, but [[http://dx.doi.org/10.1126/science.1151540|as sealevel has varied extensively over the geological history]], displaying an Early Cretaceous reconstruction at, say 110 Million years, with present-day shorelines might be a bit misleading. 
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 When I started to work on [[http://www.solid-earth-discuss.net/5/41/2013/sed-5-41-2013.html|South Atlantic plate kinematics]], I realised that, albeit being quite useful, some smaller plates would simply be missed by the grid marks. Also, one would also have to reassign plate ids for any new set of polygons one is working with and sometimes a bit of an update to the way things are being done is also refreshing. The routines which were used to generate these gridmark files (in the old PLATES *.dat format) were written in Fortran and I don't have a compiled version for my OS at hand and knowing the pain associated with this exercise I opted for a writing a new routine from scratch in Python tailored for use with GPlates. When I started to work on [[http://www.solid-earth-discuss.net/5/41/2013/sed-5-41-2013.html|South Atlantic plate kinematics]], I realised that, albeit being quite useful, some smaller plates would simply be missed by the grid marks. Also, one would also have to reassign plate ids for any new set of polygons one is working with and sometimes a bit of an update to the way things are being done is also refreshing. The routines which were used to generate these gridmark files (in the old PLATES *.dat format) were written in Fortran and I don't have a compiled version for my OS at hand and knowing the pain associated with this exercise I opted for a writing a new routine from scratch in Python tailored for use with GPlates.
  
-The result of this is  a short script called "CreateGraticuleLines.py" in my [[http://bitbucket.org/chhei/gptools|gptools repository]] on Atlassian's BitBucket which borrows command line options from [[http://generic-mapping-tools.org|GMT]]. I'll give a brief overview about the usage. First, either clone the toolbox using+The result of this is  a short script called "CreateGraticuleLines.py" in my [[hhttps://code.paleoearthlabs.org/gptools/file?name=graticules/CreateGraticuleLines.py&ci=tip|gptools repository]] which borrows command line options from [[http://generic-mapping-tools.org|GMT]]. I'll give a brief overview about the usage. First, either clone the toolbox using the [[https://fossil-scm.org|Fossil]] scm tool:
  
 <code bash> <code bash>
-git clone https://bitbucket.org/chhei/gptools.git+fossil clone https://code.paleoearthlabs.org/gptools/
 </code> </code>
  
-or simply download a zipped archive (either from [[https://bitbucket.org/chhei/gptools|the overview]] or from [[https://bitbucket.org/chhei/gptools/downloads|the Downloads]] page under 'branches'). Open the terminal, cd to the place where you have downloaded the archive, unzip and type:+or download a zipped archive (either from [[https://code.paleoearthlabs.org/gptools/download|here]] or clone a downstream GIT mirror of the fossil repos from [[https://git.sr.ht/~chhei/gptools/|my Sourcehut repository]]). Open the terminal, cd to the place where you have downloaded the archive, unzip and type:
  
 <code bash> <code bash>
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 will create the following file for GPlates (by default the output name for the file is ''Graticule.gpml''): will create the following file for GPlates (by default the output name for the file is ''Graticule.gpml''):
  
 +{{ :tectonicwaters:2013:graticule_europe.png |Graticule lines feature collection showing a 1-degree graticule covering most of Europe. Note that all lines are individual features.}}
 +
 +Once you load plate polygons into GPlates along with the graticule lines, you can use the cookie-cutting functionality in GPlates to cut the lines and assign individual plate IDs along with an "age of appearance" (set to 0 Ma by the script). It should then somehow look like this:
 +
 +{{ :tectonicwaters:2013:graticulecookiecut.png |A global graticule (using the default settings) cookie-cut and age-assigned along with plate polygons.}}
 +
 +Once you have cookie-cut and age-assigned the graticule lines, you can reconstruct them like any other feature in GPlates. Note that areas without plate ID and changed ages of appearance will not display once you step back beyond 0 Ma (present day). Here's another screenshot:
 +
 +{{ :tectonicwaters:2013:graticulereconstructed.png |Graticule lines as reconstructable features - cookie cut to plate polygons and rotated back to 100 Ma.}}
 +
 +If you now export your reconstruction as set of GMT files, you can now use GMT's psxy to plot a graticule mesh on top of your reconstruction maps using various line styles. A last example from my South Atlantic maps:
 +
 +{{ :tectonicwaters:2013:graticule_example_satl.png |An example of the application of the reconstructed graticules here as thin gray dashed lines (Heine et al., 2013)}}
  
 +Similarly, this will also work when using GPlates' SVG export. You can of course also export your graticule file in GPlates to different formats - such as ESRI Shapefile or OGR GMT plain text format ("Save as" functionality in GPlates' feature manager).
  
 +Happy map making. For bug reports and improvement suggestions please use the [[hhttps://code.paleoearthlabs.org/gptools/reportlist|issue tracker]] or the commenting functionality here.
  
 ~~DISCUSSION~~ ~~DISCUSSION~~