@article{7b9b1ae3cf4e44ea9349807ba9b2801a,
title = "Crustal Anisotropy in the Martian Lowlands From Surface Waves",
abstract = "The largest seismic event ever recorded on Mars, with a moment magnitude of 4.7 ± 0.2, is the first event to produce both Love and Rayleigh wave signals. We measured their group velocity dispersion between about 15 and 40 s period and found that no isotropic depth-dependent velocity model could explain the two types of waves wave simultaneously, likely indicating the presence of seismic anisotropy. Inversions of Love and Rayleigh waves yielded velocity models with horizontally polarized shear waves traveling faster than vertically polarized shear waves in the top 10–25 km. We discuss the possible origins of this signal, including the preferred orientation of anisotropic crystals due to shear deformation, alignment of cracks, layered intrusions due to an impact, horizontal layering due to the presence of a large-scale sediment layer on top of the crust, and alternation of sedimentation and basalt layers deposits due to large volcanic eruptions.",
keywords = "Mars, crust, inversion, seismic anisotropy, seismic waves, surface waves",
author = "C. Beghein and J. Li and E. Weidner and R. Maguire and J. Wookey and V. Leki{\'c} and P. Lognonn{\'e} and W. Banerdt",
note = "Funding Information: We thank Dr. Caroline Eakin and Dr. Joshua Russell for their constructive reviews of our manuscript. C.B. also wishes to thank Dr. Jeremy W. Boyce for the discussions that helped with the interpretation of our results. We acknowledge NASA, CNES, their partner agencies and Institutions (UKSA, SSO, DLR, JPL, IPGP-CNRS, ETHZ, IC, MPS-MPG) and the flight operations team at JPL, SISMOC, MSDS, IRIS-DMC and PDS for providing SEED SEIS data. This is ICN 271. This research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). C. B., J. L., and E. W. were funded by NASA InSight PSP Grant 80NSSC18K1679. J.W. was funded by UKSA Aurora Grant ST/T002972/1. PL is funded by the french space agency, CNES and by Agence Nationale de la recherche (ANR-19-CE31-0008-08 and ANR-18-IDEX-0001). Funding Information: We thank Dr. Caroline Eakin and Dr. Joshua Russell for their constructive reviews of our manuscript. C.B. also wishes to thank Dr. Jeremy W. Boyce for the discussions that helped with the interpretation of our results. We acknowledge NASA, CNES, their partner agencies and Institutions (UKSA, SSO, DLR, JPL, IPGP‐CNRS, ETHZ, IC, MPS‐MPG) and the flight operations team at JPL, SISMOC, MSDS, IRIS‐DMC and PDS for providing SEED SEIS data. This is ICN 271. This research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). C. B., J. L., and E. W. were funded by NASA InSight PSP Grant 80NSSC18K1679. J.W. was funded by UKSA Aurora Grant ST/T002972/1. PL is funded by the french space agency, CNES and by Agence Nationale de la recherche (ANR‐19‐CE31‐0008‐08 and ANR‐18‐IDEX‐0001). Publisher Copyright: {\textcopyright} 2022. The Authors.",
year = "2022",
month = dec,
day = "28",
doi = "10.1029/2022GL101508",
language = "English (US)",
volume = "49",
journal = "Geophysical Research Letters",
issn = "0094-8276",
publisher = "American Geophysical Union",
number = "24",
}