Alaska Dispatch

Starting Sunday afternoon, a series of small earthquakes began repeating near Mount Redoubt's summit, prompting the Alaska Volcanco Observatory to raise the volcano alert level to yellow.

Tina Neal, a geologist at the U.S. Geological Survey, said AVO officials haven't seen activity like this since spring when the volcano was in active eruption. There are several different outcomes that could result from this new activity, she said.

"It could slowly die off and go back to sleep, or this could be reflecting new lava and gas coming out of the volcano, which could lead to an eruption," she said.

Another possibility, Neal said, is that the lava dome could become unstable and fail. That would cause an avalanche down the north slope of the volcano and produce a big ash cloud.

When Mount Redoubt has erupted in the past, it threatened the Drift River Oil Terminal and its storage tanks of crude oil. The tanks were emptied after Redoubt began erupting in March.

A Chevron spokeswoman, Margaret Cooper, said in an email that the Cook Inlet Pipe Line Company, which is operated by Chevron, has contingency plans in place and is monitoring the situation at Mount Redoubt closely.

Volcano Cam 1

Here are links to stories from January and February, when Redoubt was last threatening to blow its lid: