Report on Cleveland (United States) — 15 August-21 August 2012
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 15 August-21 August 2012
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2012. Report on Cleveland (United States) (Sennert, S, ed.). Weekly Volcanic Activity Report, 15 August-21 August 2012. Smithsonian Institution and US Geological Survey.
52.825°N, 169.944°W; summit elev. 1730 m
All times are local (unless otherwise noted)
AVO reported that nothing unusual was observed at Cleveland in cloudy to partly cloudy satellite images during 15-16, 18, and 20-21 August. A small explosion was detected on 17 August by seismic and infrasound instruments on neighboring volcanoes. No evidence of an ash cloud was visible in satellite images following the event. Another small explosion on 19 August produced a low-level ash cloud, observed in satellite imagery, that drifted SE. Retrospective analysis of ground-coupled airwaves in seismic data further confirmed the explosion. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.
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.