Preliminary Analysis of Horizontal to Vertical Spectral Ratio of InSight Seismic Data on Mars

Since February 2019, The InSight mission has obtained high-quality continuous seismic and meteorological data on Mars. This study analyzes the seismic data by the end of September 2019, which are mainly ambient noise, and also include the known Marsqaukes, dust devils and HP3 self-hammering signals. The horizontal to vertical spectral ratio method is adopted to calculate the H/V curves of Martian seismic data.

The H/V curves of short period (SP) data observed on the ground show obvious diurnal variation, and are affected by local meteorological conditions. The highest peak of H/V curves may reflect the wind-induced mechanical vibration of the lander as observed in the preliminary studies on Earth. Considering the H/V peak frequency band, the particle motion in local daytime is primarily linearity with a fixed azimuth on the horizontal plane, while the particle trace in local night time is close to ellipsoid. In addition to the highest peak, H/V peaks show minor peaks in the ranges of 1-5 Hz and 14-26 Hz. Finally, possible effects of the observed Marsquakes, dust devils and HP3 self-hammering signals on H/V curves of SP data are also discussed.