chimera

A package to translate StagYY output to seismic velocities.

This project is developed in collaboration with the Centre for Advanced Research Computing, University College London.

About

This simple python package allows StagYY, StagPy, axiSEM, Perple_X talk to each other.

It uses StagPy to load the Pressure (P), Temperature (P), Compositional (C) and Density fields ouptut by the geodynamic modeling code StagYY. Then, these fields are interpolated on the finer AxiSEM grid. Then, it translates the P, T fields into thermoelastic properties for each composition (Adiabatic K, G moduli and Density). It does so based on Perple_X thermodynamic tables supplied for each composition (a modified version of the phempg is used to import the tab file). Then, the thermoelastic properties are averaged via a Voigt-Reuss-Hill scheme to create a geodynamically self-consistent seismic velocity model that can be later fed into AxiSEM as lateral heterogeneities.

Project Team

Matteo Desiderio (ucfbmde@ucl.ac.uk)

Research Software Engineering Contact

Centre for Advanced Research Computing, University College London (arc.collaborations@ucl.ac.uk)

Built With

• Framework 1
• Framework 2
• Framework 3

Getting Started

Prerequisites

chimera requires Python 3.10–3.12.

Installation

We recommend installing in a project specific virtual environment created using a environment management tool such as Conda. To install the latest development version of chimera using pip in the currently active environment run

sh pip install git+https://github.com/MatteoDesiderio/chimera.git

Alternatively create a local clone of the repository with

sh git clone https://github.com/MatteoDesiderio/chimera.git

and then install in editable mode by running

sh pip install -e .

Running Locally

How to run the application on your local system.

Running Tests

Tests can be run across all compatible Python versions in isolated environments using tox by running

sh tox

To run tests manually in a Python environment with pytest installed run

sh pytest tests

again from the root of the repository.

Building Documentation

The MkDocs HTML documentation can be built locally by running

sh tox -e docs

from the root of the repository. The built documentation will be written to site.

Alternatively to build and preview the documentation locally, in a Python environment with the optional docs dependencies installed, run

sh mkdocs serve

Roadmap

• [x] Initial Research
• [ ] Minimum viable product <-- You are Here
• [ ] Alpha Release
• [ ] Feature-Complete Release

References

• Tackley, P.J. (2008) 'Modelling compressible mantle convection with large viscosity contrasts in a three-dimensional spherical shell using the yin-yang grid', Physics of the Earth and Planetary Interiors, 171(1), pp. 7–18. Available at: https://doi.org/10.1016/j.pepi.2008.08.005.
• Connolly, J.A.D. (2005) 'Computation of phase equilibria by linear programming: A tool for geodynamic modeling and its application to subduction zone decarbonation', Earth and Planetary Science Letters, 236(1–2), pp. 524–541. Available at: https://doi.org/10.1016/j.epsl.2005.04.033.
• Morison, A.; Ulvrova, M.; Labrosse S. ; B4rsh; theofatou; tfrass49 (2022) 'StagPython/StagPy': Zenodo. Available at: https://doi.org/10.5281/ZENODO.6388133.
• Nissen-Meyer, T.; van Driel, M.; Stähler, S. C.; Hosseini, K.; Hempel, S.; Auer, L.; Colombi, A. and Fournier, A. (2014) 'AxiSEM: broadband 3-D seismic wavefields in axisymmetric media', Solid Earth, 5(1), pp. 425–445. Available at: https://doi.org/10.5194/se-5-425-2014.