High‐Frequency Seismic Events on Mars Observed by InSight

Abstract

Since the InSight lander (Banerdt et al., 2013) successfully deployed its extremely sensitive seismometer (Lognonné et al., 2019) together with a complete geophysical observatory on the surface of Mars, an unprecedented continuous data stream has become available that has opened new avenues to understanding the red planet. The first results include new observations of atmospheric (Banfield et al., 2020) and magnetic phenomena (Johnson et al., 2020). Seismological data from the very broad band (VBB) instrument that is part of the Seismic Experiment for Interior Structure (SEIS) package (Lognonné et al., 2019) have demonstrated that Mars is seismically active (Banerdt et al., 2020; Giardini et al., 2020), and information

Extramartian forcing of Mars seismicity at Rieger periods

“…One of the few remaining undisputed such claims is by Bai and Cliver (1990), who suggested that the P Rg behavior could be simulated with a damped, periodically forced nonlinear oscillator, which exhibits both periodic and chaotic behavior. The generation of Mars seismicity tidally-resonantly is supported additionally by the facts that mechanical resonance can induce both small earthquakes (Ferrazzini and Aki, 1987) and small marsquakes (Suemoto et al, 2020;van Driel et al, 2021) and that both strong earthquakes (Omerbashich, 2020a) and strong moonquakes (Omerbashich, 2020b) occur at tidal resonance periods. Besides, externally forced variations in the planetary magnetic shielding can give rise to surges of currents in the crust, which in turn can trigger seismicity (Simpson, 1968).…”

“…To look into possible external drivers of the Martian planetary dynamics, I spectrally analyze the Marsquakes Catalog by van Driel et al (2021). As cataloged for the 2019-2020 time interval, the corrected InSight data reveal Martian planetary dynamics primarily characterized by temporally clustered rupturing and an annual (orbitally induced) variation in events frequency, Figure 1.…”

“…Both local and the background seismic noise on Mars are much lower than on Earth, without the constant tremor produced by mechanical resonances. (Ceylan et al, 2021;van Driel et al, 2021) In what follows, I use the InSight seismic data to spectrally examine the band of highest areophysical energies to determine if any external forcing contributes to the peculiarities of Martian seismicity.…”

“…Data used in this study were from the Marsquakes Catalog by van Driel et al (2021; their corrected Supplementary Table 2). The least-squares spectral analysis scientific software LSSA v.5.0, based on the rigorous method by Vaníček (1969Vaníček ( , 1971, was used to compute spectra.…”

“…Figure 2. GV spectrum (solid curve) of the Marsquakes Catalog byvan Driel et al (2021) in the 1-6 months band of strongest planetary energies. The B-C combined-quality time series turned out sufficient for extraction of dominant forcing.…”