Last update at 1 p.m. on Sunday, April 17

The Alaska Volcano Observatory says sensors show the Cleveland Volcano has quieted down after Saturday’s eruption.

“Seismicity tapered to background levels within an hour of yesterday’s explosion, and no unusual seismicity has since been detected,” seismologists said on the AVO website.

Cloud coverage in the area at 30,000 feet has continued to prevent AVO from viewing the volcano via satellite, but no ash cloud has been detected above the clouds.

The color code for the volcano was still orange Sunday afternoon, and the the aviation alert level was at “watch.”

Original Story

Seismologists are watching the Cleveland Volcano along the Aleutian chain after sensors showed an explosion, according to the Alaska Volcano Observatory (AVO).

The explosion was recorded just before 11 a.m., AVO said in a statement.

“We detected an explosion using infrasound equipment, which basically senses air pressure and it can detect explosions from really far away, like in remote volcanoes like Cleveland,” said Jessica Larsen, with the University of Alaska Fairbanks Geophysical Institute. “And then it also showed up on the seismic data. So we would classify that as an eruption. Usually these eruptions from Cleveland can be short duration explosions and then some variable amount of time might pass before we see another one.”

Larsen said there was no evidence of increased activity at the volcano in the days leading up to the eruption.

AVO was not able to get an immediate look at the volcano, as cloud coverage in the area prevented satellite viewing. So far no ash cloud has been reported and Larsen said no aviation warnings have been issued.

The volcano’s color code status was upgraded to orange while the alert level is at “watch,” currently.

The Cleveland Volcano is located on the western side of Chuginadak Island, an uninhabited island in the eastern Aleutian Islands. The Tana Volcano is also on the island, but Larsen said it is less active than Cleveland.

“We typically monitor Cleveland because it’s frequently active,” she said.

The last significant activity exhibited by the Cleveland Volcano occurred in 2001, according to AVO, when “three explosive events” created an ash cloud that went as high as 39,000 feet, as well as a lava flow and “hot avalanche” that reached the water.