Benchmarking Single-station Focal Mechanism Inversion to Characterize Martian Crustal Anisotropy
Description:
On the surface of Mars, only one 3-component sensor was installed as part of the Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport (InSight) mission. Estimating the location and focal mechanisms of detected Marsquakes has thus been challenging, and yet approximations have been made to obtain these source parameters. Namely, studies of focal mechanism determination have tended to assume a purely double-couple (DC) source to simplify the grid search for the optimal fault parameters. However, this ignores the effects of deformation represented in the Compensated Linear Vector Dipole (CLVD) component. This has led to ambiguity in the obtained mechanisms for events such as S0173a and S0173ab. DC and CLVD-containing mechanisms have been used to characterize seismic anisotropy in terrestrial subducting slabs. Consequently, there is a need to explore the non-DC components of these events to reduce ambiguity and estimate crustal Martian anisotropy. In this study, we tested the ability of single-station Bayesian and grid-search techniques to reproduce the DC and CLVD components of known terrestrial focal mechanisms. Comparing the results of each method, we found that an approach combining grid search and Bayesian techniques works best at reproducing known terrestrial mechanisms. To quantify the uncertainty in using single-station-determined mechanisms in an anisotropy inversion, we inverted a terrestrial focal mechanism catalog to compare with known anisotropy results. With our terrestrial benchmark complete, we can proceed with applying our focal mechanism inversion to Marsquakes and invert for Martian crustal anisotropy.
Session: Planetary and Gravitational Wave Seismology [Poster]
Type: Poster
Date: 4/15/2026
Presentation Time: 08:00 AM (local time)
Presenting Author: Saeed Mohanna
Student Presenter: Yes
Invited Presentation:
Poster Number: 138
Authors
Saeed Mohanna Presenting Author saeedmohanna@g.ucla.edu University of California, Los Angeles |
Nayaab Singh singhnayaab.c@gmail.com University of California, Los Angeles |
Lingsen Meng Corresponding Author lsmeng@g.ucla.edu University of California, Los Angeles |
Jiaqi Li lijiaqi315@pku.edu.cn Peking University |
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Benchmarking Single-station Focal Mechanism Inversion to Characterize Martian Crustal Anisotropy
Category
Planetary and Gravitational Wave Seismology