An Alaska volcano that has been intermittently oozing lava and releasing small bursts of ash and steam since June erupted with new ferocity on Friday, sending clouds of ash more than 3 miles (4.8 km) into the sky, scientists said.
The latest eruptions from the 8,225-foot (2,507-metre) Veniaminof Volcano, on the Alaska Peninsula nearly 500 miles (805 km) southwest of Anchorage, marked some of the strongest unrest detected at the site this summer and may intensify, the Alaska Volcano Observatory warned.
But the eruptions were not believed to be linked to a large, 7.0-magnitude earthquake that struck Friday in waters off the remote Alaska island of Adak, nearly 800 miles southwest of Veniaminof in the Aleutians chain, said John Power, the observatory's scientist in charge.
"The plate tectonics are the same, but there's no direct relationship between the volcano and the earthquake," he said.
The quake was felt strongly on Adak, a former U.S. Navy station now home to a commercial fishing and maritime service center, and was followed by numerous aftershocks, the city manager said.
Shaking also was felt in Atka, a tiny native Aleut village 65 miles northeast of the quake's center. But there were no initial reports of injuries or severe damage.
Large quakes and volcanic eruptions are fairly common in southwestern Alaska and the Aleutian Islands, which lie in one of the most seismically active parts of the United States.
Ash spewed from Veniaminof has already dusted the nearby village of Perryville, a fishing town with 112 residents, and light ash was expected to fall in other communities, according to the volcano observatory, jointly run by the state and federal governments and the University of Alaska, at Fairbanks.
The new ash clouds, rising 15,000 to 20,000 feet into air, were higher than those produced earlier this summer, but air traffic was not reported to have been affected, said Allen Kenitzer, a Federal Aviation Administration spokesman.
Veniaminof, one of three Alaska volcanoes that have been restless this summer, began its latest eruptive episode in mid-June. But until now, ash clouds have been very small, mostly limited to the area around the peak's summit. Since June, hot gas and lava have melting the snow and ice at the volcano's upper reaches, leaving bare rock exposed.
Earlier this year, eruptions at another volcano in the same region, Pavlof, disrupted regional air flights, but scientists determined in early August that its eruptive phase had ended.