Aeolian sediment transport on Io from lava-frost interactions

TL;DR

This study suggests that wind-driven sediment transport, facilitated by lava-frost interactions and sublimation vapor flows, may significantly modify Io's surface, adding a new mechanism to its geological processes.

Contribution

It introduces the concept that sublimation-driven saltation from lava-frost interactions can influence Io's surface modification, a novel mechanism not previously considered.

Findings

Saltation possible if frost > 155 K

Linear features resemble dunes on other planets

Aeolian processes may shape Io's landscape

Abstract

Surface modification on Jupiter's volcanically active moon, Io, has to date been attributed almost exclusively to lava emplacement and volcanic plume deposits. Here we demonstrate that wind-blown transport of sediment may also be altering the Ionian surface. Specifically, shallow subsurface interactions between lava and Io's widespread sulfur dioxide (SO$_2$) frost can produce localized sublimation vapor flows with sufficient gas densities to enable particle saltation. We calculate anticipated outgassing velocities from lava-SO$_2$ frost interactions, and compare these to the saltation thresholds predicted when accounting for the tenuous nature of the sublimated vapor. We find that saltation may occur if frost temperatures surpass 155 K. Finally we make the first measurements of the dimensions of linear features in images from the Galileo probe, previously termed "ridges", which demonstrate certain similarities to dunes on other planetary bodies. Io joins a growing list of bodies with tenuous and transient atmospheres where aeolian sediment transport may be an important control on the landscape.