The Source Parameter of S1222a Marsquake obtained from Spectral Analyses
using Empirical Green's Function
NASA InSight mission revealed that Mars is seismically active today and
identified a region with high activity called Cerberus Fossae. Since
then, the origin of marsquakes has been an important question in Mars
seismology. On 2022/05/04, InSight seismometer detected the largest
marsquake during the mission, named S1222a. The source was estimated to
be outside the Cerberus Fossae and it would be important to constrain
the source parameters of this remarkable event. In this study, we
estimate the source parameters of S1222a through spectral analyses.
Since we found that seismic spectra of S1222a are heavily contaminated,
we performed Empirical Green’s Function analyses. We found that the
corner frequencies are 0.34-0.54 Hz for the P wave and 0.17-0.24 Hz for
the S wave. These values are slightly higher than those of seismic
events at Cerberus Fossae, which implies a faster rupture at the source
and different origin for S1222a.