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Researchers have raised the alert status at Mount Redoubt, a volcano in southern Alaska, after another increase in seismic activity.

"Shallow earthquake activity under the volcano has been as high as 26 events per 10-minute period," officials at the Alaska Volcano Observatory said Sunday in a statement announcing that the alert level was raised to "watch" status.

Although no eruption has occurred, the scientists said the increase in seismic activity "likely represents either the upward movement of magma or pressurization of the system." Read full article »

All About Geology • Alaska • Anchorage • U.S. Geological Survey