AVO reported that during 29 July-4 August satellite images detected strongly elevated surface temperatures at Cleveland's summit consistent with growth of a new lava dome. A field crew working in the area on 1 August reported frequent rockfalls on the volcano. A weak infrasound signal was much smaller than the explosion detected on 21 July; the signal may have been related to gas emissions, also consistent with lava-dome effusion. A very small gas plume was visible in webcam images during 2-3 August, and steam emissions were observed on 4 August. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

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)