AVO reported that during 12-19 June meteorological cloud cover often prevented satellite views of Cleveland. Elevated surface temperatures at the summit were detected using infrared imagery during 12-13 and 18-19 June. A pilot report, a web camera image, and infrasound data all indicated that an ash-producing explosion occurred around 1405 on 19 June. The pilot report suggested that the cloud altitude was 10 km (35,000 ft) a.s.l. and the infrasound data indicated that the eruption duration was short. The Volcano Alert Level was raised to Watch and the Aviation Color Code was raised to Orange.

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.

Source: US Geological Survey Alaska Volcano Observatory (AVO)