Scientists warn of possible eruption at restless Alaska volcano

A “nuisance” volcano on a remote Alaska Aleutian island is showing signs of a potentially disruptive explosion in the coming days that could disrupt air traffic, scientists said on Wednesday.

Cleveland Volcano, a 5,676-foot (1,730-meter) peak about 950 miles (1,500 km) southwest of Anchorage, has been extruding lava from its crater – a sign of something more serious to come in the next days or possibly weeks, according to the Alaska Volcano Observatory.

The observatory, jointly operated by federal, state and University of Alaska scientists, has raised Cleveland’s alert code to “orange,” one level below the “red” status indicating an ongoing and major eruption that could affect aviation.

Cleveland is one of Alaska’s most restless volcanoes and has been trembling and belching bits of ash on and off for about the past 15 years.

“It’s sort of a little nuisance volcano,” said University of Alaska scientist Jeff Freymueller, coordinating scientist with the Alaska Volcano Observatory.

But the recent days’ formation of lava, if the volcano’s history is any guide, is a precursor to more powerful activity, Freymueller said. The lava acts like a cap on Cleveland’s vent, and there is a good chance of a powerful explosion to blow off that cap, he said.

A big Cleveland ash cloud could interfere with commercial air traffic. “Things that get to 30,000 feet, or even close to that, would start affecting trans-Pacific flights,” Freymueller said.

In 2001, the volcano produced such an explosion, sending ash as high as 40,000 feet (12,000 meters). Most of Cleveland’s recent ash clouds have risen to no more than half that height, according to the observatory’s records.

“The problem is we can never be sure it won’t do something bigger,” Freymueller said. That is the reason for the “orange” alert, he said. “We just have to keep watching and make sure we have the information out.”