ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Thursday, November 13, 2014, 12:17 PM AKST (Thursday, November 13, 2014, 21:17 UTC)

PAVLOF VOLCANO (VNUM #312030)
55°25'2" N 161°53'37" W, Summit Elevation 8261 ft (2518 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Pavlof Volcano began a low-level eruptive event yesterday afternoon about 3:00 pm AKST (00:00 UTC on 13 November). The activity has been characterized by ash emissions to about 9000 feet (2.7 km) above sea level, lava fountaining from a vent just north of the summit, and flows of rock debris and ash descending the north flank of the volcano. Minor ash emissions were visible in the FAA-operated web camera in Cold Bay beginning around 4:50 pm AKST yesterday (1:50 UTC on 13 November). Observations from ground observers in Cold Bay coincided with a subtle but distinct increase in seismic activity, and the appearance of a thermal signal at the summit of Pavlof evident in satellite images at 5:40 pm AKST (02:40 UTC 13 November). Since these initial reports of activity, seismic activity has continued to increase gradually and the thermal signal at the summit remains evident in satellite data. Cloud cover has obscured the volcano and no new observations on ash emissions are available. However, the level of seismicity suggests that ash emission continues.

Past historical eruptions of Pavlof have been characterized by moderate amounts of ash emission, with ash plumes typically rising as high as high as 20,000 feet (6.1 km) above sea level, but occasionally higher. Near-vent accumulations of spatter produced by lava fountaining occasionally collapse and form hot rock avalanches that sweep down the flanks of the volcano. These hot rock avalanches run out over ice and snow and generate melt water, which leads to the development of sediment-water flows known as lahars. Lahars at Pavlof are capable of inundating the main drainages that head on the volcano, and these include the Leontovich and Cathedral Rivers on the north side of the volcano. At the present level of activity, lahars are not expected to be particularly large or hazardous, but streams on the north flank of the volcano could experience sudden increases in flow if or when eruptive activity intensifies. Hot rock avalanches will be limited to the flanks of the volcano and may extend 2-4 km (1.25-2.5 miles) from the vent. During other Pavlof eruptions, ash fallout has been greatest on the proximal flanks of the volcano, but occasionally trace amounts of ash reach nearby communities, including Cold Bay, Sand Point, Nelson Lagoon, and King Cove.

SHISHALDIN VOLCANO (VNUM #311360)
54°45'19" N 163°58'16" W, Summit Elevation 9373 ft (2857 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Low-level eruptive activity likely continues. Seismicity remains elevated and satellite and web camera observations were obscured by clouds over the past day.

CLEVELAND VOLCANO (VNUM #311240)
52°49'20" N 169°56'42" W, Summit Elevation 5676 ft (1730 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

Vigorous steaming from the summit crater was observed in web camera images yesterday, but clouds have obscured the view this morning. Steam emissions like these are routinely observed at Cleveland and do not necessarily indicate an increase in volcanic unrest. Satellite observations were mostly obscured by clouds and seismicity remains low.

OTHER ALASKA VOLCANOES

Other Alaska volcanoes show no signs of significant unrest: http://www.avo.alaska.edu/activity/

AVO scientists conduct daily checks of earthquake activity at all seismically-monitored volcanoes, examine web camera and satellite images for evidence of airborne ash and elevated surface temperatures, and consult other monitoring data as needed.

For definitions of Aviation Color Codes and Volcano Alert Levels, see: http://www.avo.alaska.edu/color_codes.php

FOR MORE INFORMATION ON ALASKA VOLCANOES: http://www.avo.alaska.edu

SUBSCRIBE TO VOLCANO ALERT MESSAGES by email: http://volcanoes.usgs.gov/vns/

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CONTACT INFORMATION:

John Power, Scientist-in-Charge, USGS
jpower@usgs.gov (907) 786-7497

Jeff Freymueller, Coordinating Scientist, UAFGI
jeff.freymueller@gi.alaska.edu (907) 322-4085

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.

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