Chaiten Volcano, Chile

After 9000 years of dormancy, Chaiten Volcano, in a remote part of southern Chile, has been in an eruptive phase since May 2008. NASA’s Earth Observatory posted these images of the 1/19/09 dome collapse yesterday:

chaiten1
Credit: NASA (Terra satellite)
NASA (Terra satellite)
Credit: NASA (Terra satellite)

These images above don’t do justice to the high resolution versions available at Earth Observatory:

NASA (Terra satellite)
Credit: NASA (Terra satellite). The river formerly went south of the town of Chaiten (meandering gray channel), but as the stream bed clogged with debris, it changed course and now goes right through the middle of the town.

In these false color images, the red areas are vegetation, and the gray areas are volcanic ash and mud.

A dome collapse is what it sounds like. Chaiten Volcano is similar to Mt. St. Helens in Washington, in that it produces viscous lava that piles up in a dome, as opposed to the fluid lava that is produced by basaltic volcanoes such as those in Hawaii. As the dome grows, it can become unstable and collapse, which is sort of like removing a cork from a bottle of champagne. The result is an eruption of ash, such as what you see in these images. (For a picture of the Chaiten dome before its collapse, click here).

This volcano is in an area with a low population density. The town of Chaiten has been evacuated since the volcano rumbled into activity eight months ago.

The Volcanism Blog gives regular updates on Chaiten Volcano.

Grace and Peace