A Tectonic Origin for the Largest Marsquake Observed by InSight

Abstract

The S1222a marsquake detected by InSight on 4 May 2022 was the largest of the mission, at 4.7. Given its resemblance to two other large seismic events (S1000a and S1094b), which were associated with the formation of fresh craters, we undertook a search for a fresh crater associated with S1222a. Such a crater would be expected to be ∼300 m in diameter and have a blast zone on the order of 180 km across. Orbital images were targeted and searched as part of an international, multi‐mission effort. Comprehensive analysis of the area using low‐ and medium‐resolution images reveals no relevant transient atmospheric phenomena and no fresh blast zone. High‐resolution coverage of the epicentral area from most spacecraft are more limited, but no fresh crater or other evidence of a new impact have been identified in those images either. We thus conclude that the S1222a event was highly likely of tectonic origin.

Marsquakes shake up views of the Red Planet’s deep interior

“…The strongest quake was a measly magnitude 4.7 ( 5 ), which wouldn’t faze the average Californian. Furthermore, only four other quakes reached or exceeded magnitude 4.…”

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“…Moreover, NASA suggests these findings may be indicative of life, noting the "possible detection of a molecule called dimethyl sulfide (DMS)," of which they state that "On Earth, this is only produced by life." Indeed, it is worth emphasizing just how rapidly our understanding of the cosmos is being challenged and revised by new technologies; for instance, just in October came evidence from the Keck Cosmic Web Imager of a "cosmic web" of "filaments connecting galaxies across vast distances" (Physics-Astronomy.com, 2023), from James Webb indications of free-floating Jupiter-sized "planets" unconnected to any star (Amos, 2023), as well as a study suggesting that a massive seismic tremor detected on Mars last year by NASA's Insight Mars lander was caused by plate tectonics, contradicting the assumption that it is geologically a "dead planet" (Fernando et al, 2023).…”

Repeated and Long‐Lasting Fault Activation on Amazonian Mars as Demonstrated by Tectonically Induced Landslides

“…The calculated displacement is far too large to result from a single event. The largest tectonic marsquake detected by InSight is M W 4.7 (S1222a; Fernando et al, 2023), assuming a displacement equivalent to the 2007 M W 4.7 Katanning earthquake (∼42 cm; Dawson et al, 2008), a 1.4 km displacement would require about 3300 M W 4.7 marsquakes. Even if (unrealistically) large marsquakes formed the shortening structure, it would still require 58 marsquakes-each equivalent to the 2011 M W 9.0 Tohoku-Oki earthquake (∼24 m maximum slip; Sato et al, 2011).…”