ALASKA VOLCANO OBSERVATORY WEEKLY UPDATE
U.S. Geological Survey
Friday, February 23, 2018, 12:27 PM AKST (Friday, February 23, 2018, 21:27 UTC)
52°49'20" N 169°56'42" W,
Summit Elevation 5676 ft (1730 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
Low level unrest continues at Cleveland Volcano. A small explosion was detected in seismic and infrasound data yesterday (06:54 UTC 22 Feb). No ash cloud was detected from this event, yet several hours after the explosion (14:15 UTC 22 Feb), satellite data show moderately elevated surface temperatures extending about 2 km ESE from the summit, indicative of a warm deposit. No activity has been observed in seismic and infrasound data, and clouds have obscured satellite views of the volcano today. No other activity was observed this week.
Future explosive activity is likely, and may occur without warning. Previous explosions have produced hazardous conditions primarily near the summit crater, but occasionally they have been large enough to produce a drifting ash cloud.
Cleveland volcano is monitored with a limited real-time seismic network, which inhibits AVO's ability to detect precursory unrest that may lead to an explosive eruption. Rapid detection of an ash-producing eruption may be possible using a combination of seismic, infrasound, lightning, and satellite data.
Cleveland volcano forms the western portion of Chuginadak Island, a remote and uninhabited island in the east central Aleutians. The volcano is located about 75 km (45 mi) west of the community of Nikolski, and 1500 km (940 mi) southwest of Anchorage. The most recent significant period of eruption began in February, 2001 and produced 3 explosive events that generated ash clouds as high as 39,000 ft above sea level. The 2001 eruption also produced a lava flow and hot avalanche that reached the sea. Since then, Cleveland has been intermittently active producing small lava flows, often followed by explosions that generate small ash clouds generally below 20,000 ft above sea level. These explosions also launch debris onto the slopes of the cone producing hot pyroclastic avalanches and lahars that sometimes reach the coastline.
OTHER ALASKA VOLCANOES
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Aaron Wech, Acting Scientist-in-Charge, USGS
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Pavel Izbekiv, Acting Coordinating Scientist, UAFGI
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The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.