A small explosion at Cleveland was recorded by the seismic network at 1155 on 8 December. A second small explosion with a higher peak amplitude was detected at 1153 on 12 December, prompting AVO to raise the Aviation Color Code to Orange and the Volcano Alert Level to Watch. No ash cloud was observed, though weather clouds obscured views of the volcano. Elevated surface temperatures were visible in satellite data on 15 December. A small explosion which occurred at 0737 on 16 December generated a minor ash cloud that drifted NE.

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)