Performance of a broadband seismometer on Europa and implications for the detection of liquid water below its icy surface

Seismologically imaging the interior of icy satellites such as Europa can constrain the presence of liquid water layers within or below their frozen outer shells, and may inform us of the potential for these environments to harbor extraterrestrial life. Here, we consider a hypothetical lander mission to Europa that includes a single three component broadband seismometer and investigate how seismic data acquired from the mission could constrain properties of Europa's ice shell and subsurface ocean. We consider a 20 day instrument operational period and limit data collection to under 500 megabytes in order to simulate practical mission requirements. We use a tidally driven seismicity model to predict the frequency and magnitude of ice-cracking events, and calculate the seismic response by simulating wave propagation through thermodynamically self consistent models of Europa's interior at frequencies up to 1 Hz. We find that long period surface waves are likely to be globally detectable for events greater than Mw 3.5 and illustrate how ice shell thickness can be constrained by inverting Rayleigh-wave group velocity measurements. Our inversions explore how both environmental noise and instrument self-generated noise affect the ability to recover interior structure. Additionally, we explore the potential of conducting a high frequency active source reflection experiment to detect a liquid layer directly below the lander. Our results demonstrate the benefit of an onboard seismic instrument even in the unlikely event that Europa is seismically quiet.