SARYCHEV PEAK VOLCANO

Perfect timing.
On June 12th, just as Russia's Sarychev Peak volcano was erupting for the first time in 20 years, the International Space Station flew directly overhead.
Astronauts had their camera ready and snapped one of the most dramatic Earth-science photos ever taken from space:Sarychev Peak Volcano eruption, Kuril Islands, is featured in this image photographed by an Expedition 20 crew member on the International Space Station.
A fortuitous orbit of the International Space Station allowed the astronauts this striking view of Sarychev volcano (Russia's Kuril Islands, northeast of Japan) in an early stage of eruption on June 12, 2009. Sarychev Peak is one of the most active volcanoes in the Kuril Island chain and is located on the northwestern end of Matua Island.

Prior to June 12, the last explosive eruption had occurred in 1989 with eruptions in 1986, 1976, 1954, and 1946 also producing lava flows. Ash from the June 2009 eruption has been detected 2407 kilometers ESE and 926 kilometers WNW of the volcano, and commercial airline flights are being diverted away from the region to minimize the danger of engine failures from ash intake.

This detailed photograph is exciting to volcanologists because it captures several phenomena that occur during the earliest stages of an explosive volcanic eruption.

The main column is one of a series of plumes that rose above Matua Island (48.1 degrees north latitude and 153.2 degrees east longitude) on June 12.

The plume appears to be a combination of brown ash and white steam.

The vigorously rising plume gives the steam a bubble-like appearance; the surrounding atmosphere has been shoved up by the shock wave of the eruption.

The smooth white cloud on top may be water condensation that resulted from rapid rising and cooling of the air mass above the ash column, and is probably a transient feature (the eruption plume is starting to punch through). The structure also indicates that little to no shearing winds were present at the time to disrupt the plume.

Another series of images, acquired 2-3 days after the start of eruptive activity, illustrate the effect of shearing winds on extent of the ash plumes across the Pacific Ocean.

By contrast, a cloud of denser, gray ash -- most probably a pyroclastic flow -- appears to be hugging the ground, descending from the volcano summit.

The rising eruption plume casts a shadow to the northwest of the island (bottom center). Brown ash at a lower altitude of the atmosphere spreads out above the ground at upper right. Low-level stratus clouds approach Matua Island from the east, wrapping around the lower slopes of the volcano. Only about 1.5 kilometers of the coastline of Matua Island (upper center) can be seen beneath the clouds and ash.