The volcano, one of the largest and most active in the region, is located halfway between Port Heiden and Port Moller on the Alaska Peninsula.

It has erupted 12 times in the last 200 years, and last erupted in 1995.

Tom Murray, the leading scientist for the observatory, said scientists recorded tremors beneath the volcano on Sept. 10, including an earthquake two miles beneath the surface.

Satellite photos could not detect steaming or surface changes, however.

"Typically these things just die back down," Murray said. "That doesn't mean that it can't still escalate quickly. But we see nothing that indicates that yet."

The Alaska Volcano Observatory puts out weekly reports on the activity levels of the volcanoes in Alaska. They can be found on the Web at www.avo.alaska.edu.

--The Associated Press