New seismic activity at Mount Redoubt, 100 miles southwest of Anchorage, has increased significantly and may be the prelude to an eruption, "perhaps within hours to days," the Alaska Volcano Observatory reported Sunday.
Geologists there upgraded the aviation color code for Redoubt from yellow to orange, indicating that an eruption may be imminent.
The 10,197-foot peak -- located about 50 miles west of Kenai and 100 miles southwest of Anchorage -- last erupted during a five-month period from December 1989 through April 1990.
Scientists keep a close eye on ground monitors on Redoubt to detect any movement.
Never miss a local story.
"Around 1 o'clock (Sunday) morning the seismic activity really started to pick up," said AVO volcanologist Dave Schneider. The shaking quieted about five hours later, but it still remains well above normal "background" tremor levels, Schneider said.
Read the full story at adn.com