Data Repository for "Influence of Glacial Isostatic Adjustment on Intraplate Stress and Seismicity in Eastern North America in the Presence of Pre-existing Weak Zones"

Description

This repository contains the data necessary to reproduce the results in Hightower et al., (2025), Influence of Glacial Isostatic Adjustment on Intraplate Stress and Seismicity in Eastern North America in the Presence of Pre-existing Weak Zones, published in Geochemistry, Geophysics, Geosystems. 

It includes the CitcomSVE-3.0 code base used for the model runs (including pre- and post-processing scripts), model inputs, model outputs, supporting data sets needed for analysis or making figures, and the scripts used to generate the figures in the paper and in the supplementary material. 

The following is a description of the files contained in the repository. Also see the README file. 

CitcomSVE-3.0-G3-Aug25.tar 

This is the CitcomSVE code base, including all pre- and post-processing scripts used for the current work. Post-processing scripts are my own and not contained within the public CitcomSVE download (though there is a set of scripts that comes with it). Post-processing scripts for the stress data can be found under the subdirectory postprocessing. postprocess_stress.sh is main script that runs all of the post-processing sub-steps needed to compute various stress variables, such as Shmax, from the stress output. This script takes a lot of arguments, so it is typically run on the cluster within a batch script that stores all the input arguments. The batch scripts for both the post-processing and the model runs themselves are contained in the respective model output directories for each model. 

You can also download the most up to date version of CitcomSVE-3.0 and its full documentation from the GitHub page of Shijie Zhong: https://github.com/shjzhong/CitcomSVE .

Data.tar

This directory contains datasets external to our own results that are used in the analysis, such as stresses from the World Stress Map, polygons for plotting and constructing the weak zones in the CitcomSVE viscosity input, and other 1D viscosity profiles for plotting, as well as the Earth models (e.g. PREM) we provide to CitcomSVE for both the real Earth model runs (model.PREM.vm5a.wrtCrust) and the Cap Load synthetic test (model.PREM.Steffen2021.volAvg).

Scripts.tar

This folder contains various scripts used for calculations and plotting, though most of the heavy calculations are done on the cluster and are contained in the postprocessing directory discussed above. The scripts here include a general function for calculating the Coulomb failure stress (compute_CFS.py) that is called from calc_CFS_onFaults.sh to calculate the CFS on specific faults for the seismic zones explored in the paper. get_stress_profile.sh samples the stress magnitudes along a given profile using GMT. 

Figures.tar

This directory contains all the scripts needed to generate the Figures in the paper and copies of the figures themselves. They plot results using data contained in the other directories, like ModelOutputs_[modelname] and Data. Given how  the zip files were individually uploaded to the repository, some of the paths in the figure scripts may need to be updated for your local machine to function properly. Some figures also utilize data from the companion paper Hightower et al., 2024 (G-cubed, Influence of Farallon Slab Loading on…  https://doi.org/10.1029/ 2024GC011493), so any file paths that reference SIDataRepository.nosync can be found in the repository for that study at https://data.caltech.edu/records/wh6q5‐80b36. 

CitcomSVE_outputs

These include the model outputs for the models presented in the paper. The names in the repository are the official model names used in my record keeping for the CitcomSVE runs and are slightly different than the simplified ones given in the paper but are more-or-less self-explanatory. However, the key for which model is which is as follows, where the repository name is given first and the name used in the paper second:

• 6G_V1D_VM5a_3 : Model GIA_VM5a 
• 6Gd_V3D_A0_1: Model GIA_A0
• 6Gd_V3D_A1_1: Model GIA_A1
• 6Gd_V3D_A1b_1: Model GIA_A1b
• CapLoad_V1D_S21_1: Synthetic benchmark case presented in supplementary material

Each of these directories contains various datasets as follows:

• [modelname]_stress_data_3Dgrids
  These are 3D netCDF files with time on the record dimension for various stress variables (e.g. second invariant of deviatoric stress, etc.) computed from the original CitcomSVE output without the addition of tectonic background stress.
   
• [modelname]_stress_data_original
  This is the original GIA stress data, without any addition of tectonic background stress. The files are labeled as follows: [modelname].[data_set].z[layer].[timestep]. Layer refers to the layer in the Earth. Our analysis is performed at 10 km depth, which is layer 2, so only those files are contained therein. For the benchmark case, we show results at 5 km depth, which is layer 1, so those are z1. Output is only for select time steps in order to save file space. 
  
  data_set may refer to any of the following:
  
  visc_stress_tensor contains the raw original stress tensor components from CitcomSVE and the viscosity. The columns are lon, lat, depth, viscosity (normalized by 1e21 Pa s), 2nd invariant of deviatoric stress, sigma_xx, sigma_yy, sigma_zz, sigma_xy, sigma_xz, sigma_yz. Please note that in CitcomSVE the x-direction is North-South (positive downward as in colatitude), the y-direction is E-W (positive eastwards), and the vertical direction is positive outward with radius. These files are not used directly in the plotting of results, rather stress_tensor_ned should be used instead (see Supplementary Material with the paper). The raw outputs are here for archiving.
  
  stress_tensor_ned contains the full stress tensor components after rotation to a North-East-Down (NED) coordinate system and positive in compression convention. These are the components used to compute Shmax, Coulomb failure stress, and all other stress variables (except the 2nd invariant of deviatoric stress, which is invariant to the coordinate system anyway). Columns are given in the header line of the data file. 
  
  stress_vars contains the stress variables computed from the NED stress tensors, including Shmax direction, S_V (the vertical stress), the principal stresses, etc. Columns are given in the header line of the data file. 
  
  This directory also contains the Shmax orientations from only GIA stress at the locations of the WSM and their misfit to those data (ShmaxAziAndMisfit file). 
   
• [modelname]_stress_data_wTBS
  This directory contains the same data sets described above, except that the tectonic background stress tensor from the mantle flow models in Hightower et al., 2024 (for the corresponding viscosity structure) has been added to the GIA stress tensor. Thus, the full stress tensors are provided (i.e. for calculating CFS on faults), and the stress variables are computed with those full stress tensors. 
  
  This directory also contains the Shmax orientations from the total stress (GIA + TBS) at the locations of the WSM and their misfit to those data (ShmaxAziAndMisfit.TBS_fromModel_[TBS_modelname] file). 
   
• [modelname]_stress_input_output_data
  This directory contains the input parameter file and batch files needed to run CitcomSVE for the given model and the post-processing, as well as a text file storing the time steps and time info (in yr) for the stress output. See CitcomSVE documentation for details on the inputfile and parameters. If present, the vertical_mesh_config.txt gives details on the vertical mesh resolution and setup needed to be specified in the input file. 
   
• CFSdata
  This directory stores precomputed Coulomb failure stress values (calculated with compute_CFS.py via calc_CFS_on_Faults.sh in the Scripts directory) for specific faults in the different seismic zones for each time step of the model). 
   
• Files_for_Plots
  This folder just contains other files needed for plotting some of the figures, like profile path coordinates or cpt files. 

CitcomSVE Inputs

IceHistories.tar

This contains the both the ice load history for the synthetic Cap Load model and from ICE-6G_D. Files include the ice load files (lon, lat, ice thickness) and the ocean function files (lon, lat, ocean function), where ocean function is 0 for land and 1 for ocean. 

For the Cap Load model, no sea level equation is employed, so ocean function is 0 everywhere. This directory also contains the script (create_iceModel.ipynb) used to construct the synthetic ice load and to make Figures S1 and S2 in the supplementary material. 

See CitcomSVE documentation and the Yuan et al., 2025 CitcomSVE-3.0 methods paper for file formatting details and how the ocean function is pre-computed. 

3D Viscosity Models

The files for the three 3D viscosity models are Visc3DInput_GIA_A0.tar, Visc3DInput_GIA_A1.tar, and Visc3DInput_GIA_A1b.tar. Each contains the 3D netCDF file of the global viscosity grid, which can be used for plotting or other purposes, as well as the text file storing the viscosities in the format required by CitcomSVE (see CitcomSVE-3.0 documentation for details on that file format). There is also a script in the preprocessing directory in the CitcomSVE code base folder that will format the viscosity text file as needed from the 3D netCDF file (format_visc_for_CitcomSVE.py). Visc3DInput_GIA_A0.tar also contains figures showing maps for each depth slice in the in the viscosity grid for reference. At the global scale, models A1 and A1b look the same as A0. The only difference is the presence of weak zones in eastern North America. 

Files

Additional details