USGS Volcano Hazards Program Volcano Update


AVO update page and observatory web site


The eruption of Mount Veniaminof volcano which began on June 13 continues. Satellite images showed intense elevated surface temperatures consistent with lava effusion at the cinder cone inside the caldera throughout the week. Seismic tremor continued throughout the week. On June 18, small, short lived ash bursts rising to less than 15,000 ft were seen in clear images from the FAA web camera in Perryville. On June 19, residents in Sandy River reported seeing ash bursts from the volcano rising to 10,000-15,000 ASL and blowing to the northeast. The volcano was obscured by weather in web camera images for the rest of the week and it is possible that ash bursts continue and are undetected. Refer to the NWS Alaska Aviation Weather Unit (http://aawu.arh.noaa.gov/) for updates on SIGMETs related to ash emissions.

Recent satellite images continue to show intense elevated surface temperatures at the cinder cone inside the caldera and seismic tremor continues. The seismic network at Veniaminof is not fully functional compared to that operating during the last eruption (2005), so the accuracy with which we can interpret ongoing seismicity is diminished.

Technical problems temporarily disabled the real-time seismic data feeds from Veniaminof on Wednesday, June 19, and were resolved within a few hours, restoring the data stream.

Recent eruptions of Veniaminof volcano have all occurred from vents located on the cinder cone inside the caldera and were characterized by brief bursts of ash emission and small explosions. Ash plumes associated with this type of activity are typically diffuse and generally do not reach more than 20,000 feet above sea level. Ash fallout is typically limited to the flanks of the volcano. Minor emissions of steam and ash may persist for for weeks to months. The current lava flow is expected to remain within the confines of the caldera. There is a possibility that activity at the volcano could increase with little to no warning.

Mount Veniaminof volcano is an andesitic stratovolcano with an ice-filled 10-km diameter summit caldera located on the Alaska Peninsula, 775 km (480 mi) southwest of Anchorage and 35 km (22 mi) north of Perryville. Veniaminof is one of the largest (~ 300 km3) and most active volcanic centers in the Aleutian Arc and has erupted at least 13 times in the past 200 years. Recent significant eruptions of the volcano occurred in 1993-95 and 2005. Both were moderate Strombolian eruptions producing intermittent low-level jets of incandescent lava fragments, and low-level emissions of steam and ash from the main intracaldera cone. During the 1993-95 activity, a small lava flow was extruded into the summit caldera ice field producing an ice pit. Minor ash-producing explosions occurred in 2002, 2004, early 2005, November 2006, and February 2008. Previous historical eruptions have produced ash plumes that reached 6,000 m (20,000 ft) above sea level and ash fallout that blanketed areas within about 40 km (25 mi) of the volcano.

Update in Common Alerting Protocol (CAP) format