ANCHORAGE, Alaska – Alaska's Cleveland Volcano is undergoing a continuous low-level eruption following an explosion early Saturday morning, scientists from the Alaska Volcano Observatory and the U.S. Geological Survey said.
Satellites and cameras suggest low-level emissions of gas, steam and ash, scientists said, and satellites detected highly elevated surface temperatures at the summit. A faint plume of ash extended eastward below 15,000 feet, but the Federal Aviation Administration said there were no flight restrictions as a result.
"Sudden explosions of blocks and ash are possible with little or no warning," scientists said. "Ash clouds, if produced, could exceed 20,000 feet above sea level."
The aviation alert level was raised from "yellow" to "orange." A major ash emission could threaten international flights.
The activity began with an explosion at 5 a.m. Saturday, followed by two others at 9:17 and 11:44 a.m. A nearby seismic network detected long-duration airwave signals that indicate a sustained eruption.
The volcano is in an isolated region of the Aleutian Islands, 940 miles southwest of Anchorage. Its most recent significant eruption began in February 2001 and featured three explosive events that sent ash clouds as high 39,000 feet above sea level. It also produced a rubbly lava flow and hot avalanche that reached the sea.
The most recent minor ash emissions were observed in November 2012.