AVO reported that elevated surface temperatures were observed over Cleveland in satellite imagery during 17-18 April. An explosion on 19 April at 0438, detected by seismometers at Makushin and Okmok volcanoes, generated an ash cloud the rose 4-6 km (13,100-19,700 ft) a.s.l. and drifted S. Satellite images showed block-and-ash deposits extending for up to 1 km down the S flank. A possible weak thermal anomaly was detected in images during 20-21 April.

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)