Report on Cleveland (United States) — 31 August-6 September 2011
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 31 August-6 September 2011
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2011. Report on Cleveland (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 31 August-6 September 2011. Smithsonian Institution and US Geological Survey.
52.825°N, 169.944°W; summit elev. 1730 m
All times are local (unless otherwise noted)
On 30 August, AVO reported that satellite observations during the previous two weeks indicated that lava-dome growth at Cleveland had paused. AVO lowered the Volcano Alert Level to Advisory and the Aviation Color Code to Yellow. During 31 August-2 September cloud cover prevented views of the summit crater, but a thermal anomaly at the summit was observed during 3-5 September. Observations on 6 September indicated that the lava dome had resumed growth, reaching 120 m in diameter and filling the floor of the crater. AVO raised the Volcano Alert Level to Watch and the Aviation Color Code to Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.
Geologic Background. 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.