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Seasonal variations of subsurface seismic velocities monitored by the SEIS-InSight seismometer on Mars

Compaire, Nicolas and Margerin, L. and Monnereau, M. and Garcia, R. and Lange, L and Calvet, M. and Dahmen, N. and Stähler, S. and Mueller, N.T. and Grott, M. and Lognonné, P. and Spohn, T. and Banerdt, W.B. (2022) Seasonal variations of subsurface seismic velocities monitored by the SEIS-InSight seismometer on Mars. Geophysical Journal International, 229 (2), pp. 776-799. Oxford University Press. doi: 10.1093/gji/ggab499. ISSN 0956-540X.

[img] PDF - Postprint version (accepted manuscript)

Official URL: https://academic.oup.com/gji/article/229/2/776/6462906


The SEIS seismometer deployed at the surface of Mars in the framework of the NASA-InSight mission has been continuously recording the ground motion at Elysium Planitia for more than one martian year. In this work, we investigate the seasonal variation of the near surface properties using both background vibrations and a particular class of high-frequency seismic events. We present measurements of relative velocity changes over one martian year and show that they can be modeled by a thermoelastic response of the Martian regolith. Several families of high-frequency seismic multiplets have been observed at various periods of the martian year. These events exhibit complex, repeatable waveforms with an emergent character and a coda that is likely composed of scattered waves. Taking advantage of these properties, we use coda wave interferometry to measure relative travel-time changes as a function of the date of occurrence of the quakes. While in some families a stretching of the coda waveform is clearly observed, in other families we observe either no variation or a clear contraction of the waveform. These various behaviors correspond to different conditions of illumination at the InSight landing site, depending on the season. Measurements of velocity changes from the analysis of background vibrations above 5 Hz are consistent with the results from coda wave interferometry. We identify a frequency band structure in the power spectral density that can be tracked over hundreds of days. This band structure is the equivalent in the frequency domain of an autocorrelogram and can be efficiently used to measure relative travel-time changes as a function of frequency. We explain how the PSD analysis allows us to circumvent the contamination of the measurements by the Lander mode excitation which is inevitable in the time domain. The observed velocity changes can be adequately modeled by the thermoelastic response of the regolith to the time-dependent incident solar flux at the seasonal scale. In particular, the model captures the time delay between the surface temperature variations and the velocity changes in the subsurface. Our observations could serve as a basis for a joint inversion of the seismic and thermal properties in the first 20 meters below InSight.

Item URL in elib:https://elib.dlr.de/148054/
Document Type:Article
Title:Seasonal variations of subsurface seismic velocities monitored by the SEIS-InSight seismometer on Mars
AuthorsInstitution or Email of AuthorsAuthor's ORCID iDORCID Put Code
Compaire, NicolasInstitut Supérieur de l'Aéronautique et de l'Espace, Toulouse Cedex 04, FranceUNSPECIFIEDUNSPECIFIED
Margerin, L.Institut de Recherche en Astrophysique et PlanétologieUNSPECIFIEDUNSPECIFIED
Monnereau, M.Institut de Recherche en Astrophysique et Planétologie, Université Toulouse III Paul Sabatier, CNRS, CNES , 14 Av. E. Belin, 31400, Toulouse, FranceUNSPECIFIEDUNSPECIFIED
Garcia, R.ISAE-SUPAERO, Toulouse University, Toulouse, FranceUNSPECIFIEDUNSPECIFIED
Lange, LLaboratoire de Météorologie Dynamique/Institut Pierre Simon Laplace (LMD/IPSL), Sorbonne Université, CNRS, École Polytechnique, École Normale Supérieure (ENS) , Campus Pierre et Marie Curie BC99, Paris, FranceUNSPECIFIEDUNSPECIFIED
Calvet, M.Institut de Recherche en Astrophysique et Planétologie, Université Toulouse III Paul Sabatier, CNRS, CNES, Toulouse, FranceUNSPECIFIEDUNSPECIFIED
Dahmen, N.Institute of Geophysics, Department of Earth Sciences, ETH Zurich, Zurich, SwitzerlandUNSPECIFIEDUNSPECIFIED
Stähler, S.Institute of Geophysics, ETH Zurich, SwitzerlandUNSPECIFIEDUNSPECIFIED
Mueller, N.T.UNSPECIFIEDhttps://orcid.org/0000-0001-9229-8921UNSPECIFIED
Grott, M.UNSPECIFIEDhttps://orcid.org/0000-0002-8613-7096UNSPECIFIED
Lognonné, P.Département de Géophysique Spatiale et Planétaire, UMR7096, Institut de Physique du Globe de Paris, Saint-Maur, FranceUNSPECIFIEDUNSPECIFIED
Spohn, T.UNSPECIFIEDhttps://orcid.org/0000-0002-9322-6660UNSPECIFIED
Banerdt, W.B.Jet Propulsion Laboratory, California Institute of Technology, Pasadena, USAUNSPECIFIEDUNSPECIFIED
Date:May 2022
Journal or Publication Title:Geophysical Journal International
Refereed publication:Yes
Open Access:Yes
Gold Open Access:No
In ISI Web of Science:Yes
Page Range:pp. 776-799
Publisher:Oxford University Press
Keywords:Seismology, seasonality
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Space Exploration
DLR - Research area:Raumfahrt
DLR - Program:R EW - Space Exploration
DLR - Research theme (Project):R - Project InSight - HP3, R - Exploration of the Solar System
Location: Berlin-Adlershof
Institutes and Institutions:Institute of Planetary Research > Planetary Physics
Institute of Planetary Research > Leitungsbereich PF
Institute of Planetary Research > Planetary Sensor Systems
Deposited By: Müller, Nils
Deposited On:07 Jan 2022 12:26
Last Modified:23 Nov 2022 13:17

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