Resonances and Lander Modes Observed by InSight on Mars (1–9 Hz)

• DOI: 10.1785/0120210056
• Publication Date: 2021-10-26T16:00:38Z
• Authors: Nikolaj L. Dahmen; Géraldine Zenhäusern; John F. Clinton; Domenico Giardini; Simon C. Stähler; Savas Ceylan; Constantinos Char...; Martin van Driel; Kenneth J. Hurst; Sharon Kedar; Philippe Lognonné; Naomi Murdoch; Robert Myhill; Mark P. Panning; William T. Pike; Martin Schimmel; Cédric Schmelzbach; John-Robert Scholz; Alexander E. Stott; Eleonore Stutzmann; William B. Banerdt
• Keywords: Seismometer; Seismic Noise; Ambient noise level

ABSTRACT The National Aeronautics and Space Administration’s (NASAs) Interior exploration using Seismic Investigations, Geodesy Heat Transport (InSight) lander successfully touched down on Mars in November 2018, and, for the first time, a seismometer was deployed surface of planet. seismic recordings reveal diurnal seasonal changes broadband noise level that are consistent with variations local atmospheric conditions. data include variety spectral peaks, which interpreted as wind-excited, mechanical resonances lander, subsurface, or artifacts produced measurement system. Understanding origin these signals is critical detection characterization marsquakes well studies investigating ambient noise. We identify major peaks up to 9 Hz, corresponding frequency range most relevant observed marsquakes. track frequency, amplitude, polarization over duration mission so far. majority can readily be classified (lander modes), latter have temperature-dependent peak wind-sensitive amplitude. Of particular interest prominent resonance at 2.4 used discriminate between events possibly by subsurface structure. In contrast modes, Hz has distinctly different features: (1) broad stable shape, slightly shifted each component; (2) predominantly vertical energy; (3) temperature-independent frequency; (4) comparatively weak amplification winds, though there slow change amplitude; (5) excitation during all excite this band. Based observations, we suggest only mode below could related ground