Seismic Scattering and Absorption Properties of Mars Estimated Through Coda Analysis on a Long-Period Surface Wave of S1222a Marsquake

On 4 May 2022, the seismometer on Mars observed the largest marsquake (S1222a) during its operation. One of the most specific features of S1222a is the long event duration lasting more than 8 hr, in addition to the clear appearance of body and surface waves. As demonstrated on Earth, by modeling a long-lasting and scattered surface wave with the radiative transfer theory under the isotropic scattering condition, we estimated the scattering and intrinsic quality factors of Mars (Q(s) and Q(i)). This study especially focused on the frequency range between 0.05-0.09 Hz, where Q(s) and Q(i) have not been constrained yet. Our results revealed that Q(i) = 1,000-1,500 and Q(s) = 30-500. By summarizing the Martian Q(i) and Q(s) estimated so far and by comparing them with those of other celestial bodies, we found that, overall, the Martian scattering and absorption properties showed Earth-like values.

Automated summary

On 4 May 2022, the largest marsquake (S1222a) was observed by the seismometer on Mars, with a long event duration lasting over 8 hours and clear body and surface waves. Using the radiative transfer theory, the scattering and intrinsic quality factors of Mars (Q(s) and Q(i)) were estimated for the frequency range between 0.05-0.09 Hz, which had not been constrained previously. The results showed that Q(i) = 1,000-1,500 and Q(s) = 30-500, indicating Earth-like scattering and absorption properties on Mars when compared with other celestial bodies.