A volcano located on Umnak Island in the western Aleutians Islands erupted on Saturday, July 12, 2008, with little warning to the ranch family who shares the island or the Alaska Volcano Observatory, which monitors the state’s hazardous volcanoes.

The crater of the Okmok Volcano is about six miles wide and 1,600 feet deep. Seismologists maintain several monitoring stations on the crater, which last erupted in 1997 and was active for eight months. More than a dozen volcanic cones are contained in the crater, which was formed about 2,000 years ago Okmok is highly active, with about 16 eruptions occurring every 10 to 20 years since 1805. .

 The initial ash and gas cloud of the current eruption reached 50,000 feet above sea level and is drifting south over the North Pacific. It caused cancellations of some air travel.

In an Associated Press story, the rancher gives a firsthand account of being up-close when a volcano erupts. He, his family, and ranch workers were rescued by a fishing vessel. He describes a sound like huge rocks rolling and an ash cloud that shut out the daylight. A small Aleut village with about 40 people is located on the other side of Umnak Island and out of the southeasterly path of the ash cloud.

 You can keep up to date on Okmok activity at http://www.avo.alaska.edu/activity/Okmok.php with satellite pictures of the ash cloud and links to images of the volcano dating back to the 1940s.