Scientists have raised Pavlof Volcano's alert level, after the volcano began showing signs of restlessness.
The Alaska Volcano Observatory issued an "advisory" for Pavlof on Monday following an ongoing tremor at the volcano, located 36 miles northeast of Cold Bay.
No eruptive activity or emissions from the summit have been observed in cloud satellite and web camera views, according to the AVO. However, the seismic activity represents an increase from background levels and scientists are thus increasing the aviation color code to "yellow" and alert level to "advisory."
The AVO said this does not mean that an eruption is likely or imminent. However, past eruptions of Pavlof occurred with little or no warning.
Pavlof's last major eruption was in 2016. According to the AVO, ash plumes as high as 40,000 feet above sea level were generated and the ash was tracked in satellite data as distant as eastern Canada. With over 40 historic eruptions, Pavlof is one of the most consistently active volcanoes in the Aleutian arc.