Not many were surprised when the Alaskan volcano Augustine erupted this week following weeks of warning signs.

Closely watched by ground-monitoring equipment, Augustine displayed seismic activity earlier this month and lead authorities to raise its alert status to yellow, or “restless.”

Augustine, which sits in the Gulf of Alaska and is known as the most active volcano in the eastern Aleutian arc, erupted on Dec. 12, 2005. Ash and steam can be seen stretching across 50 miles (80 kilometers) in this image taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite.

The biggest eruption to spew forth from Augustine occurred in 1883, when the volcano’s dome collapsed. Over time, the dome has grown to its pre-1883 eruption. Augustine also erupted in 1986, sending forth a cascade of ash, rock fragments and gas, though its history dates back farther than records cover. Its oldest volcanic rocks are more than 40,000 years old.

Researchers at the Alaska Volcano Observatory have made a live view of Augustine available by clicking here.

-- SPACE.com Staff

Credit: Jesse Allen/Earth Observatory/MODIS Rapid Response Team.