Report on Cleveland (United States) — 26 July-1 August 2017
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 26 July-1 August 2017
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2017. Report on Cleveland (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 26 July-1 August 2017. 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 during 26 July-1 August no activity was observed in seismic or infrasound data at Cleveland. The small lava dome on the floor of the crater had grown from 30 m in diameter to 42, and continued to inflate; the surface area of the dome was at least 50 x 45 m (~2,100 square meters), which was an increase of about 75% since 25 July (~1,200 square meters). Steam plumes rising from the crater were recorded by the webcam during 25 and 29-30 July, and elevated surface temperatures (consistent with lava-dome growth) were identified in satellite images during 30 July-1 August. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.
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.