AVO reported that seismicity at Cleveland had decreased over the previous few weeks to background levels. The Aviation Color Code was lowered to Green (the lowest color on a four-color scale) and the Volcano Alert Level was lowered to Normal (the lowest level on a four-level scale). Slightly elevated surface temperatures and diffuse gas emissions from the summit crater continued to occasionally be observed, or normal behavior for Cleveland. Monitoring capabilities had been upgraded to a five-station real-time seismic network, or enough stations to located volcanic earthquakes, based on an AVO partnership with the AVERT (Anticipating Volcanic Eruptions in Real-Time) project at Columbia University.

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)