Did ocean motion carve Enceladus's tiger stripes?

Saturn's moon Enceladus is enveloped by a thick ice shell containing a liquid water ocean. Four parallel fissures, known as the "tiger stripes," are found at the moon's south pole, each spewing water vapor and materials from the ocean into space. Previous theories suggest the stripes were formed primarily by ice shell processes, but a new study proposes ocean waves play a crucial role.

Researchers D. Y. Abdulah and colleagues, in a paper published in AGU Advances, used mathematical analysis and simulations to explore how waves in Enceladus' subsurface ocean could interact with the ice shell, leading to the stripes' formation. The moon's irregular orbit causes the ice shell to wobble relative to its ocean. The wobble creates uneven topography on the fissure's underside and generates waves that travel tens of kilometers through the ocean to the seafloor, then reflecting back up and breaking against an adjacent ice shell, releasing heat that melts the ice from below.

This process could lead to the formation of additional parallel fissures, approximately 35 kilometers apart, matching the spacing of the existing tiger stripes. If the mechanism is correct, it could provide insights into the ocean's density changes with depth. Further modeling and a potential future mission to Enceladus could help refine and test the proposed mechanism and its implications.