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. GPlates can generate and export flowlines.

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:

icons/digitise_multipoint_35.png Point Geometries

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.

Note Flowlines can be created at any reconstruction time.


The next step is to allocate left and right plate ids - representing the plates on either side of the flowline - and times of appearance and disappearance.

Note Flowlines will only be generated between the feature’s time of appearance and time of disappearance.


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.


Finally assign your new flowline feature to a feature collection.


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.


3. Saving flowlines

Flowline feature collections can be saved in gpml format and loaded like other feature collections.

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.

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.


When exporting to GMT format, each reconstructed flowline point is output in the form (lon, lat, time).

Example of an exported flowline GMT file:
>reconstructionTime 0
>Flowline <identity>GPlates-a5e5b41c-089a-4d3f-a877-b5cc0088f43f</identity> <revision>GPlates-550e75b5-5d27-4146-b83d-93ccfa3be165</revision>
> Left plate: 802
> Right plate: 801
> Times: 0,5,10,15,20,25,30,35,40,45,50
> Seed point: Lat: -50.3407, Lon: 139.229
> Left-plate flowline
  139.229000      -50.340700       0.000000
  139.197261      -51.887165       5.000000
  139.325022      -53.317310      10.000000
  139.565701      -54.653181      15.000000
  139.856508      -55.970876      20.000000
  140.163463      -57.330579      25.000000
  140.449153      -58.889273      30.000000
  140.746852      -60.278992      35.000000
  141.049859      -61.184592      40.000000
  141.374462      -61.686198      45.000000
  141.655807      -62.007476      50.000000