Veniaminof volcano
© AVO/Tim Plucinski
Veniaminof volcano in 2006.
An Alaska Peninsula volcano that has long been a hotbed of seismic activity prompted a new alert from volcanologists Thursday, though no signs of an eruption have been seen so far.

According to a statement from the U.S. Geological Survey's Alaska Volcano Observatory, the alert level at Mount Veniaminof -- a volcanic peak about 480 miles southwest of Anchorage and 22 miles north of Perryville -- has been raised to "advisory," and the aviation color code has gone from green to yellow.

According to a USGS guide on volcano alert levels, Veniaminof's current aviation color code and alert level both indicate that it is "exhibiting signs of elevated unrest above known background level."

"Over the past day, seismicity at Veniaminof has increased and is ongoing in the form of volcanic tremor," staff at the observatory wrote. "No eruptive activity is observed in web camera or satellite views from today."

Veniaminof has seen numerous eruptions over the last century, including one that produced a 20,000-foot ash plume and ash falls over a 25-mile radius in 1939. Since the turn of the century, it has had at least six eruptions, including one in 2013 that generated lava and ash plumes.

John Power, the observatory's scientist in charge, said the recent activity seems to be "something new," with no significant activity preceding it in recent weeks.

"This seems to be what we have seen at Veniaminof numerous times in the past," Power said. "It's a very frequently active system, and this seems to be in keeping with prior eruptions."

While scientists don't have any predictions on whether the latest seismic event at Veniaminof will lead to a new eruption, Power said the volcano will remain under observation.

"We are watching the situation very closely," Power said.