U.S. officials issued a red aviation alert for the Shishaldin Volcano in Alaska after significant seismic activity was reported over the weekend.
The agency said the plume has shifted, becoming ashier, and is about 20,000 feet in height, officials said. They added that the cloud was moving to the east.
“The apparent increase in the vigor of the eruption and the increase ash production prompted the Alaska Volcano Observatory to increase the color code and alert level to RED/WARNING,” the observatory’s statement added.
During that eruption, the Volcano Observatory raised the alert level to a code red. Ash clouds initially obscured the volcano but satellite imagery confirmed the eruption, U.S. Geological Survey geophysicist Hans Schwaiger said at the time, according to The Associated Press.
The eruptions were confirmed by lighting and satellite data, the observatory said. More explosions could occur or activity could significantly decrease with little warning, according to the observatory.
The volcano is 679 miles southwest of Anchorage near the center of Unimak Island, the largest island in the Aleutians. False Pass, a village of 40 people, is on the island’s east side. Unless winds change, the cloud would move north of False Pass and would not pose a threat, Schwaiger said.
Before that, the volcano erupted in December and spewed ash 25,000 feet into the air.
Shishaldin is one of the most active volcanoes in the Aleutian volcanic arc, with at least 54 episodes of unrest including more than 24 confirmed eruptions since 1775, according to the observatory.
Alaska is located along the Pacific “Ring of Fire,” a seismically active region that encircles the Pacific Ocean.