AVO reported that an ash cloud from Cleveland rose to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted 80 km ESE on 29 December. AVO raised the Volcano Alert Level to Watch and the Aviation Color Code to Orange. During 30 December-3 January there were no new signs of explosive activity; the Volcano Alert Level was lowered to Advisory and the Aviation Color Code to Yellow on 30 December. No current 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)