Alaska Officials Lower Pavlof Volcano Threat Risk

Scientists have downgraded the threat level of Alaska's Pavlof Volcano to "yellow."

The Alaska Volcano Observatory has announced it lowered the advisory level for Pavlof today from orange to yellow, because activity has decreased significantly but continues to be closely monitored.

That means the volcano is still producing some rumbling beneath the surface with a few small explosions periodically.

Located about 625 miles southwest of Anchorage, the volcano began erupting May 13, with reported plumes of steam, gas and ash reaching as high as 22,000 feet and visible on satellite images, not to mention nearby communities. The uptick is volcanic activity coincided with an elevated level of seismic movement in the area.

The observatory said the 8,262-foot volcano has subsided over the last three days --- but that doesn't the eruption is over.

Rick Wessels, a geophysicist at the Alaska Volcano Observatory, indicated researchers finally acquired clear satellite images of Pavlof last Friday, which showed considerably less ash than was being produce mere days before.

In human terms, that means Aleutian communities such as Sand Point and Nelson Lagoon, which were dusted by ash before, likely don't have to worry about that again for a while.  

"The plume seemed to be pretty low-level - beneath 15,000 feet. Pretty short," Wessels said. "It wasn't nearly the intensity that we saw a week ago."

At this point, the continuing activity is "basically a low level of what we call volcanic tremor, which just means as fluids and lava are moving through the volcano. It just is kind of a continuous, low-level subsonic hum," he said. "And then there's still discrete little explosions we can see on the seismic and infrasound networks. So we are able to hear these little pops once in a while, where things get pushed out a little more energetically."

Wessels said he and other scientists are now in the process of going through the records of past eruptions trying to figure out what phase of the eruption process Pavlof is in.

"We're not sure if this is a respite from bigger activity or if this is the weaning stages of the end of activity," said Wessels. "Really, the only we can tell is just watch it for a few more days and see what it does."