Long Period Seismology on Titan in the Presence of a Methane Clathrate Lid

Abstract

Previous 1-D spherically symmetric seismic modeling studies have shown that in the presence of a clathrate lid on Titan significant thermal profile differences result, particularly in comparison to a pure water ice shell. In turn, these thermal differences would lead to notable changes in the waveform amplitudes and seismic phase arrival times. In this study we investigate the feasibility of using surface waves dispersion to explore the structure of Titan's ice shell. We investigate the ability to measure and observe the frequency-dependent signals (0.003–0.100 Hz) and their utility in being able to detect existence of a methane-clathrate lid. We find that we are unlikely to resolve the clathrate-lid's existence using long-period techniques, and this could be a limitation for studying very thick ice shells ($>\approx$ 20 km) of icy ocean worlds. We did resolve the frequency range of flexural waves transitioning to a Stoneley wave (mode) in the fundamental mode, and see a Rayleigh wave in the first overtone for a 100 km ice shell on Titan for a simulated quake.