For horizontal and vertical intervals, we have (from the SubMachine paper):
The models were accessed in many different original parameterizations. Horizontally, these can be regular or irregular localized grids, or spherical harmonic basis functions; in the third dimension, regular or irregular depth layers, possibly interpolated by spline functions.
We have linearly interpolated each model on a regular horizontal grid of 0.5° × 0.5° using Generic Mapping Tools (GMT, version 5.3.1; Wessel et al., 2013). The highest lateral resolution in the original model parameterizations was 1° × 1°, hence, interpolation on a grid of 0.5° × 0.5° retains all original information and introduces no aliasing error, while keeping the computational effort for processing and plotting acceptable.
In the vertical dimension, we retain the exact, discrete depth layers specified by the original model parameterizations. This assures that all the depth-dependent complexities in tomography models are preserved, such as velocity changes in the lithosphere-asthenosphere boundary, transition zone, and core-mantle boundary regions. In case of irregular parameterization in depth (e.g., tetrahedral volume mesh), our interpolation extracted uniform depth increments of 50 km.
Moreover, for each discontinuity in the background model, two depths closely bracketing that discontinuity were extracted and stored in the dataset, e.g., depth slices at 650 and 670 km depth in case of a 660 km discontinuity. If a user requests data that do not coincide with points on this fine, precomputed grid, SubMachine interpolates linearly on the fly.
Depending on your model parameterization, a coarser depth interval might suffice. SubMachine linearly interpolates two bracketing depth profiles if the requested depth is not in the database. For instance, the SL2013sv model, we use the following depths:
[25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, 700]
This can of course extended for models that go down to the core mantle boundary.
Please send model files in the format below:
{MODELNAME}_{DEPTH}.txt
Example: SL2013sv_100.txt contains columns:
lon, lat, dv/v(%)Please send the model files to orfeus.submachine@gmail.com. We will process the models and upload them to the database after a short review process.