"About midday on 10 December, pilot Tom Madsen (president, Aleutian Air) noted an anomalous 400+ m-high eruption column over Mt. Cleveland from the ground at Nikolski, Umnak Island (about 65 km ENE of the volcano). The top of the vertical column had drifted at least 0.5 km to the N. The white eruption cloud probably consisted principally of steam with only minor amounts of ash, if any. Based on observations by Madsen, Mt. Cleveland has been steaming fairly continuously since at least 1982, when he began flying regularly from Dutch Harbor (Unalaska Island) to Atka (Atka Island). Reeder has received several reports about steam-blast and phreatomagmatic eruptions at Mt. Cleveland over the last several years."

Geological Summary. The beautifully symmetrical Mount Cleveland stratovolcano is situated at the western end of the uninhabited Chuginadak Island. It lies SE across Carlisle Pass strait from Carlisle volcano and NE across Chuginadak Pass strait from Herbert volcano. Joined to the rest of Chuginadak Island by a low isthmus, Cleveland is the highest of the Islands of the Four Mountains group and is one of the most active of the Aleutian Islands. The native name, Chuginadak, refers to the Aleut goddess of fire, who was thought to reside on the volcano. Numerous large lava flows descend the steep-sided flanks. It is possible that some 18th-to-19th century eruptions attributed to Carlisle should be ascribed to Cleveland (Miller et al., 1998). In 1944 it produced the only known fatality from an Aleutian eruption. Recent eruptions have been characterized by short-lived explosive ash emissions, at times accompanied by lava fountaining and lava flows down the flanks.

Information Contacts: J. Reeder, Alaska Div. of Geol. and Geophys. Surveys.