Constraints on the shallow elastic and anelastic structure of Mars from InSight seismic data
Philippe Lognonné, W. B. Banerdt, W. T. Pike, Domenico Giardini, Ulrich R. Christensen, R. García, Taïchi Kawamura, S. Kedar, Brigitte Knapmeyer‐Endrun, Ludovic Margerin, F. Nimmo, M. P. Panning, Benoît Tauzin, John‐Robert Scholz, Daniele Antonangeli, Salma Barkaoui, É. Beucler, Felix Bissig, Nienke Brinkman, Marie Calvet, Savas Ceylan, Constantinos Charalambous, Paul M. Davis, Martin van Driel, M. Drilleau, Lucile Fayon, Rakshit Joshi, B. Kenda, Amir Khan, Martin Knapmeyer, V. Lekić, John McClean, D. Mimoun, Naomi Murdoch, Lu Pan, Clément Perrin, Baptiste Pinot, L. Pou, Sabrina Ménina, S. Rodríguez, Cédric Schmelzbach, N. C. Schmerr, David Sollberger, Aymeric Spiga, Simon C. Stähler, Alexander Stott, É. Stutzmann, Saikiran Tharimena, Rudolf Widmer‐Schnidrig, Фредрик Андерссон, V. Ansan, Caroline Beghein, Maren Böse, E. Bozdağ, John Clinton, I. J. Daubar, Pierre Delage, Nobuaki Fuji, M. P. Golombek, Matthias Grott, Anna Horleston, K. Hurst, J. C. E. Irving, A. W. B. Jacob, J. Knollenberg, Sanford Krasner, C. Krause, R. D. Lorenz, Chloé Michaut, Robert Myhill, Tarje Nissen‐Meyer, Jan ten Pierick, Ana‐Catalina Plesa, Cathy Quantin‐Nataf, Johan O. A. Robertsson, L. Rochas, Martín Schimmel, S. E. Smrekar, Tilman Spohn, N. A. Teanby, Jeroen Tromp, Julien Vallade, Nicolas Verdier, Christos Vrettos, R. C. Weber, D. Banfield, Elizabeth Ann Barrett, M. Bierwirth, S. B. Calcutt, Nicolas Compaire, C. L. Johnson, D. Mance, F. Euchner, L. Kerjean, G. Mainsant, A. Mocquet, J. A. Rodríguez‐Manfredi, G. Pont, Ph. Laudet, T. Nebut
Abstract
Mars’s seismic activity and noise have been monitored since January 2019 by the seismometer of the InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) lander. At night, Mars is extremely quiet; seismic noise is about 500 times lower than Earth’s microseismic noise at periods between 4 s and 30 s. The recorded seismic noise increases during the day due to ground deformations induced by convective atmospheric vortices and ground-transferred wind-generated lander noise. Here we constrain properties of the crust beneath InSight, using signals from atmospheric vortices and from the hammering of InSight’s Heat Flow and Physical Properties (HP3) instrument, as well as the three largest Marsquakes detected as of September 2019. From receiver function analysis, we infer that the uppermost 8–11 km of the crust is highly altered and/or fractured. We measure the crustal diffusivity and intrinsic attenuation using multiscattering analysis and find that seismic attenuation is about three times larger than on the Moon, which suggests that the crust contains small amounts of volatiles. The crust beneath the InSight lander on Mars is altered or fractured to 8–11 km depth and may bear volatiles, according to an analysis of seismic noise and wave scattering recorded by InSight’s seismometer.