Pavlof Volcano is a stratovolcano of the Aleutian Range on the Alaska Peninsula. It has been one of the most active in the United States since 1980. When the new eruption began it was sending an ash cloud to 37,000 feet above sea level, extending 400 miles NE. The volcano gave 25 minutes warning before the onset of the eruption. The alert level was raised to "Warning" and the aviation color code was raised to "Red", which indicates incoming eruption with high levels of ash.