Response of InSight resonance modes to environmental factors on Mars

Abstract

The InSight (Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport) mission has recorded continuous ambient noise signals with many spectral peaks since its landing in 2018. The majority of these peaks are modes produced by instrumental vibrations and are associated with environmental factors, such as temperature and wind energy fluctuations. Understanding how these modes react under various conditions is crucial because it aids in identifying their origins. In this study, we analyzed the three-component spectra of InSight recordings from sols 184–738 and obtained the horizontal-to-vertical spectral ratio (HVSR, also known as H/V) curves for different time intervals. The primary modes, such as those at 3.3 and 4.1 Hz, exhibited different behaviors, suggesting diverse origins. Some modes were sensitive to low temperature and some were sensitive to high temperature. Additionally, we investigated the influence of wind and temperature on the H/V curve. The peak frequency was mainly affected by temperature, whereas the H/V value was not associated with the temperature or wind only. Characterizing these modes and elucidating their origins are significant for processing signals from InSight and can provide valuable guidance for designing future planetary seismometers.

Keywords

• mars
• insight
• spectral peaks
• h/v curve