Near-surface flow of volcanic gases on Io

Significant near-surface flow of gas several hundred kilometers from Pele (Plume 1) on Io is indicated by a series of bright, elongate albedo markings. Particles produced at small, local vents are apparently carried as much as 70 km farther “downwind” from Pele. The gas densities and velocities necessary to suspend 0.1 to 10 μm particles at such a distance imply mass flow rates of 10⁷ to 10⁹ g/sec. Such flow rates are consistent with other estimates of mass transport by the plume. The large flow rates so far from the source allow an estimate of the rate of resurfacing of Io by lava flows and pyroclastics that is independent of estimates based on meteorite flux or on the amount of solids carried within the plumes themselves.