A small explosive eruption of Cleveland on 2 October prompted AVO to raise the Volcano Alert Level to Watch and the Aviation Color Code to Orange. A detached ash cloud at estimated altitudes of 4.6-6.1 km (15,000-20,000 ft) a.s.l. was seen on satellite imagery; the cloud drifted about 600 km NE and dispersed over the Bering Sea. No further activity was reported. On 5 October, the Volcano Alert Level was lowered to Advisory and the Aviation Color Code was lowered to Yellow. No seismic information was available because Cleveland does not have a real-time seismic network.

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)