  Ice-covered ocean worlds possess diverse energy sources and associated
mechanisms that are capable of driving significant seismic activity, but to
date no measurements of their seismic activity have been obtained. Such
investigations could probe their transport properties and radial structures,
with possibilities for locating and characterizing trapped liquids that may
host life and yielding critical constraints on redox fluxes, and thus on
habitability. Modeling efforts have examined seismic sources from tectonic
fracturing and impacts. Here, we describe other possible seismic sources, their
associations with science questions constraining habitability, and the
feasibility of implementing such investigations. We argue, by analogy with the
Moon, that detectable seismic activity on tidally flexed ocean worlds should
occur frequently. Their ices fracture more easily than rocks, and dissipate
more tidal energy than the <1 GW of the Moon and Mars. Icy ocean worlds also
should create less thermal noise for a due to their greater distance and
consequently smaller diurnal temperature variations. They also lack substantial
atmospheres (except in the case of Titan) that would create additional noise.
Thus, seismic experiments could be less complex and less susceptible to noise
than prior or planned planetary seismology investigations of the Moon or Mars.
