AVO reported that unrest at Cleveland continued during 18-23 July, though nothing significant was detected in seismic or infrasound data. Weakly elevated surface temperatures were identified in satellite images during 18 and 23-24 July; meteorological cloud cover hindered views of the crater on most of the other days. A small deposit of blocks within the summit crater and just below the E crater rim observed only in satellite data suggested the occurrence of a very small explosion undetectable in seismic and pressure sensor data. 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)