Alaska Volcano Observatory

News

April 19th - anniversary of Shishaldin 1999 and Pavlof 1986!
Posted: April 19, 2014

In this image, a lazy eruption column rises from Pavlof's summit; the jagged volcanic rocks of the Aghileen Pinnacles stretch towards the Bering Sea in the left-hand portion of the image

Shishaldin in eruption, April 23, 1999

Two of Alaska's most active volcanoes have eruption anniversaries today (April 19). Both are beautiful, symmetric stratocones that exemplify Aleutian volcanism.

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Ground-coupled airwaves and explosion signals at Shishaldin
Posted: April 10, 2014

seismic waveforms at Shishaldin

Over the past few weeks we've been seeing regular small explosions in the seismic record coming from Shishaldin's crater. Each explosion shows up as a low frequency seismic wave that travels through the ground, followed by a high frequency airwave pulse. The airwaves arrive later because energy from the explosion travels more slowly through the air than it does through the ground. While small explosions are often part of the background activity at Shishaldin, we haven't seen them showing up this clearly in the past 2 years. Elevated surface temperatures suggest there is fresh lava in the crater. Since the explosions were observed around the time that the lava was erupted into the crater, the two are probably closely related. We can't say whether the explosions are directly caused by the erupting lava, though, or whether they are just small puffs of gas coming from the crater floor.

Loss of Critical Volcano Monitoring Information in Alaska
Posted: February 10, 2014

The Alaska Volcano Observatory (AVO) has experienced numerous seismic station failures and our ability to monitor activity at some volcanoes has failed or is heavily impaired. For volcanoes with failed ground instrumentation networks, AVO is unable to (1) assess whether this volcano may be building towards an eruption and/or (2) quickly confirm or dismiss reports of activity. Because these volcanoes are no longer seismically monitored, they will move from volcano alert level Normal and Aviation Color Code Green to "unassigned". As at other volcanoes without real-time seismic networks, AVO will continue to use satellite and infrasound data, and reports from pilots and ground observers to detect signs of eruptive activity. We will update this news item with links to announcements of monitoring status changes as they occur.

Monitoring instruments at Aniakchak Volcano can no longer seismically monitor unrest at the volcano. The final Aniakchak station failure was confirmed on January 23. The Information Statement for Aniakchak is
here.

Monitoring instruments at Fourpeaked volcano can no longer seismically monitor unrest at the volcano. The Information Statement from February 7 that moved Fourpeaked to Unassigned is here.

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Last Activity Report

Get these reports emailed to you: USGS VNS

ALASKA VOLCANO OBSERVATORY DAILY UPDATESunday, April 20, 2014 11:36 AM AKDT (Sunday, April 20, 2014 19:36 UTC)

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

Weakly elevated surface temperature in the summit crater observed during clear periods over the past day. Web camera images mostly obscured by clouds. No significant changes observed in seismic data.

VENIAMINOF VOLCANO (VNUM #312070)
56°11'52" N 159°23'35" W, Summit Elevation 8225 ft (2507 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

Seismicity over the past day is slightly above background. Web camera images show typical steaming from the previously active cone. No activity observed in satellite images.

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

No activity observed in satellite images during clear periods over the past day.

FOLLOW AVO ON FACEBOOK: https://facebook.com/alaska.avo

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TELEPHONE RECORDING ON ALASKA VOLCANO STATUS (907) 786-7478

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.