Pavlof Volcano, located on the Aleutian Islands, is one of the most active in the region. A volcano on a remote Alaskan island has "abruptly erupted" - sending plumes of ash more than 20,000ft into the air and triggering a flight warning. The Pavlof Volcano, located on the Aleutian Islands, began erupting on Sunday afternoon, according to the Alaska Volcano Observatory. CNN said that a volcano alert warning remained in effect on Monday morning, and the aviation warning colour code remained red, its highest level.