Do deep depressions on Enceladus originate from hydrothermal vents?

Introduction 

Icy moon Enceladus has been mostly studied for its South Polar region and geysers gushing out from a series of faults called Tiger Stripes. Less attention has been dedicated to several depressions, nearly 3.5-km-deep and 100-km-wide, scattered over the moon’s surface (1,2,3). Absence of fractures, no correlation with geological boundaries, and overall smooth profiles seemingly disprove an impact or a tectonic origin. Instead, they are thought to be associated with local thinning of the ice shell above hydrothermal vents from the moon’s porous core (4). However, this hypothesis has yet to be investigated. Here, we do so by modeling a response of a viscous ice shell to spatial variations in the heat flux coming from the subsurface ocean. In order to relate our results to Cassini mission observations, we evaluate the depth and the width of our modeled depressions, together with the stress in their vicinity.