Volcanic Ash in Alaska, February 19, 2001

AVO detected a volcanic ash cloud emanating from Cleveland Volcano in satellite imagery that began 1500 Z (0600 AST) in the Islands of the Four Mountains. The first Sigmet for ash was issued by the Alaska Aviation Weather Unit at 19/1835Z (9:35 am Monday) in response to a call from Alaska Vsolcano Observatory in Fairbanks. The first public warning for ash was issued within 25 minutes of the SIGMET. Ash cloud was drifting southeast of Cleveland and reached about 17,000 feet asl. Another higher ash cloud extended to the north about 60 miles and reached an estimated altitude of 30,000+ ft asl.Ashl was reported in Nikolski. The ash cloud purportedly grew to more than 100 miles long as it was blown eastward. Mt. Cleveland forms the western half of Chuginadak Island, a remote and uninhabited island in the east central Aleutians. It is located 25 miles west of Umnak Island and 40 miles west of the community of Nikolski. A distinctively symmetrical sratovolcano, Cleveland has erupted 11 times since 1893. Its most recent eruption on May 25, 1994 sent a short-lived ash plume to about 35,000 ft altitude. Ash fall from this eruption impacted the north and east flanks of the volcano, and small debris flows may have formed on the southwest flank. On October 20, 1994, AVO identified a possible ash plume on satellite imagery, however, no eruption was confirmed.