NASA ISS photo of Raikoke in eruption taken June 22. Active plume with water vapor collar at the base. Water vapor collar at the base may be due to ambient air sucked upwards with the plume. Alternately, it may be due to interaction of pyroclastic flows with surrounding sea water. Image courtesy NASA Earth Observatory.
ISS astronaut photo of Sarychev Peak eruptive plume June 12, 2009. 3 pyroclastic flows are visible at the base of the plume. Brown flow to the left toward the shoreline. Grey – white flow toward the bottom of the photo. Finally, a third dark brown flow to the right toward the opposite shoreline. Image originally courtesy NASA. https://en.wikipedia.org/wiki/Sarychev_Peak