Marsquake

Illustration of the shadow zone of a P-wave for Earth. S-waves don't penetrate the outer core

A marsquake is a quake which, much like an earthquake, is a shaking of the surface or interior of the planet. Such quakes may occur with a shift in the planet's interior, such as the result of plate tectonics, from which most quakes on Earth originate, or possibly from hotspots such as Olympus Mons or the Tharsis Montes. The detection and analysis of marsquakes are informative to probing the interior structure of Mars, as well as potentially identifying whether any of Mars's many volcanoes continue to be volcanically active.[1]

Quakes have been observed and well-documented on the Moon, and there is evidence of past quakes on Venus. Marsquakes were first detected but not confirmed by the Viking mission in 1976.[2] Marsquakes were detected and confirmed by the InSight mission in 2019.[3] Using InSight data and analysis, the Viking marsquakes were confirmed in 2023.[4] Compelling evidence has been found that Mars has in the past been seismically more active, with clear magnetic striping over a large region of southern Mars. Magnetic striping on Earth is often a sign of a region of particularly thin crust splitting and spreading, forming new land in the slowly separating rifts; a prime example of this being the Mid-Atlantic Ridge. However, no clear spreading ridge has been found in this region, suggesting that another, possibly non-seismic explanation may be needed.

The 4,000 km (2,500 mi) long canyon system, Valles Marineris, has been suggested to be the remnant of an ancient Martian strike-slip fault.[5] The first confirmed seismic event emanating from Valles Marineris, a quake with a magnitude of 4.2, was detected by InSight on 25 August 2021, proving it to be an active fault.[6]

  1. ^ Kornei, Katherine (22 January 2022). "Bouncing Boulders Point to Quakes on Mars – A preponderance of boulder tracks on the red planet may be evidence of recent seismic activity". The New York Times. Retrieved 22 January 2022.
  2. ^ Anderson, Don L.; Miller, W. F.; Latham, G. V.; Nakamura, Y.; Toksoz, M. N.; Dainty, M. N.; Duennebier, F. K.; Lazarewicz, A. R.; Kovach, R. L.; Knight, T. C. D. (September 30, 1977). "Seismology on Mars". Journal of Geophysical Research. 82 (28): 22. doi:10.1029/JS082i028p04524 – via American Geophysical Union.
  3. ^ Greicius, Tony (2021-04-01). "NASA's InSight Detects Two Sizable Quakes on Mars". NASA. Retrieved 2021-07-24.
  4. ^ Lazarewicz, Andrew R. (10 July 2023). "Viking Marsquakes 1976 -- Seismic Archaeology". Journal of Geophysical Research: Planets. 128 (e2022JE007660): 20. doi:10.1029/2022JE007660. S2CID 259927674 – via American Geophysical Union.
  5. ^ Yin, A. (4 June 2012). "Structural analysis of the Valles Marineris fault zone: Possible evidence for large-scale strike-slip faulting on Mars". Lithosphere. 4 (4): 286–330. Bibcode:2012Lsphe...4..286Y. doi:10.1130/L192.1.
  6. ^ "Two Largest Marsquakes To Date Recorded From Planet's Far Side". Seismological Society of America (Press release). SpaceRef. 26 April 2022. Retrieved 26 April 2022.