2013-06-01: Note: page needs updating – some links have changed. For the AVO’s excellent site, follow the observatory link in the text below.

NOTE: January 5/10: Due to reduced seismic activity, alert levels are reduced to green again.

NOTE: The Alaska Volcano Observatory has issued an alert upgrade to yellow due to increased seismic activity at the volcano…
See monitors below (all monitors now up…)

2009-12-28 12:37:19 – Status Report:
Earlier this morning, AVO elevated the Aviation Color Code to YELLOW and the Volcano Alert Level to ADVISORY at Redoubt Volcano. Beginning about 4:00 pm AKDT on December 27 (0100 December 28 UTC), small repetitive earthquakes began to occur in the vicinity of the volcano’s summit. Activity is continuing this morning; these earthquakes are very small and have decreased in frequency overnight. These earthquakes represent a departure from seismicity at the volcano over the past five months. (See http://www.avo.alaska.edu/webicorders/Redoubt/RSO_EHZ_AV.php). Clouds currently obscure web camera and satellite views of the volcano.

These earthquakes could be precursory to renewed eruptive activity at the volcano and increased instability of the lava dome. Whether this will result in explosive activity or collapse of the lava dome is unknown at this time. However, there is a heightened possibility of volcanic activity that would produce a volcanic ash cloud and associated ash fall, pyroclastic avalanches, and lahars and flooding down the Drift River.

AVO is monitoring the situation closely and will attempt to overfly the volcano when weather allows.

NOTE: October 1/09: The Alaska Volcano Observatory has lowered the status of Mt. Reodubt to green-normal, indicating that the volcano has returned to its pre-eruptive state. The AVO will continue to monitor Mt. Redoubt for activity. Ephemerata Weather Radar will keep the active monitoring link open, as the seismic webcorders are maintained and EWR monitors them in real-time in the blog page.

NOTE: July 1/09: The Alaska Volcano Observatory has lowered the status of Mt. Reduobt to yellow-advisory. While seismic activity remains above background, dome growth has slowed substantially, and while there still remains a risk, its believed at this time to be much lower. Check with the AVO site linked below.

NOTE: May 5/09: The seismic stations are showing increased low level activity. The dome is growing and there remains concern that it may explosively erupt. The AVO reports that the seismic signature is similar to that which preceded the March and April eruptions.

NOTE: Apr 19/09: Webicorder REF appears to be back online, but so too is RSO, so I’ve swapped in RSO. Webicorder RSO, closest to the volcano, was damaged in one of the first eruptions, but has been recently serviced. RDN is believed to be buried in snow, and has a poor trace. Rather than noting changes each time, I’ll simply update the trace info below according to which is running well. All are presently accessible in any case. Redoubt is still condition “Orange-Watch” and dome-building continues. EWRadar is offline while things are quiet.

NOTE: Apr 17/09: Webicorder REF is still having difficulty, so I’ve swapped it out with NCD (AVO has crews in the field today – perhaps REF is being messed with). NCD is not quite as sensitive, but is giving a steady trace. Both are still available in the text line below the display.
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Redoubt Volcano is approximately 109 miles east of Anchorage, Alaska, on the north shore of Cook Inlet, and about 135 miles east of Wasilla. It lies at the head of the Drift River Glacier. The Drift River oil terminus is at the inlet at the outflow of the Drift River Valley. Lahar flows (icy ash flows) have reached the oil terminal buildings, and pose a threat to the terminal facilities. Plans are being made to off -load a quantity of the oil currently in storage at the facility.

The small, shallow repeating volcanic earthquakes indicative of lava dome growth that continued at the rate of 3-4/minute the last few days, subsided, then resulted in a strong eruption this morning at 6am AKDT (1400UTC). as can be seen on station REF.

The webcams HUT and DFR below and the station REF seismic trace following, are continuously updated from the Alaska Volcano Observatory site. The radar scan is assembled from NWS data by Ephemerata Weather Radar – refresh browser as desired for most current information. The seismic trace will give an indication of possible impending eruptions by its increased activity.
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A sunrise view of the Apr 04/09 eruption from the Hut webcam is immediately below. A composite reflectivity radar time-lapse scan, annotated, is here: April 4th eruption. There are several images below the active monitors and a link to the AVO image gallery.

Sunrise on the Apr 04/09 eruption of Mt. Redoubt, from the Hut webcam

Sunrise on the Apr 04/09 eruption of Mt. Redoubt, from the Hut webcam


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Hut Webcam (Online):

Webcam is presently offline from AVO
(Refresh for most recent webcam image. Sunrise is +/- 8am AKDT, 12Noon EDT, 16UTC, sunset 12 hours later).

DFR Webcam (Online):

Webcam DFR is presently offline from AVO
DFR webcam is 12.2 km NE of Redoubt, and takes a picture approximately every 2 hours.

RSO_EHZ_AV Webicorder* (Online):

Webicorder update is presently offline from AVO
Webicorder RSO_EHZ_AV 24hr. (refresh for webicorder update – Active trace is the very bottom one).

NCT_EHZ_AV Webicorder* (Online):

Webicorder update is presently offline from AVO
Webicorder NCT_EHZ_AV 24hr. (refresh for webicorder update – Active trace is the very bottom one).

RDN_EHZ_AV Webicorder* (Online):

Webicorder update is presently offline from AVO
Webicorder RDN_EHZ_AV 24hr. (refresh for webicorder update – Active trace is the very bottom one).

REF_EHZ_AV Webicorder* (Online):

Webicorder update is presently offline from AVO
Webicorder REF_EHZ_AV 24hr. (refresh for webicorder update – Active trace is the very bottom one).

( Alternate webicorders are Webicorder NCT_EHZ_AV, Webicorder RDN_EHZ_AV and Webicorder REF_EHZ_AV . Webicorder updates and Hut views courtesy of AVO/USGS. )

Its important to note that the seismic instruments also detect earthquakes and other tremors not directly associated with Redoubt eruptions. In some cases, it takes a bit of work for AVO and USGS staff to determine if a seismic signature signals an impending volcanic event, or whether it is a collateral signal from a different event. Earthquakes are common in the Pacific rim Ring of Fire zone.

  • A webicorder is a software interface for a modern digital seismic instrument that produces a visual “chart trace” like those produced by the original drum chart pen recorders. Seismic instruments measure the vibration in the ground from tremors, earthquakes, eruptions, etc. They may also be influenced by vehicles, wind, and, in Alaska, passing bears and Democrats.

EWradar scan: (Offline) (Redoubt Volcano is centered in the blue circle across Cook inlet from the Kenai radar station. For scale,the circle has a diameter of 12 miles, the distance from the volcano to Kenai is 38 mi.):

Radar scan is presently offline from Ephemerata Weather Radar
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These are some of the many spectacular images of Mt. Redoubt in the Alaska Volcano Observatory image gallery.

Redoubt, as seen on the morning of April 16, 2009, from Cape Starichkof (~ 5 mi north of Anchor Point), Kenai Peninsula. April 16, 2009 08:18:00 ADT. Photograph courtesy of Dennis Anderson.

Some context - Redoubt, as seen northerly across Cook Inlet on the morning of April 16, 2009, from Cape Starichkof (~ 5 mi north of Anchor Point), Kenai Peninsula. April 16, 2009 08:18:00 ADT. Photograph courtesy of Dennis Anderson.

Photograph of Redoubt Volcano in eruption taken during observation and gas data collection flight on March 30, 2009. View is to the east. Continuous emission of volcanic gas, water vapor, and ash is producing a plume rising to about 10,000 to 15,000 feet above sea level. AVO scientists observed ash falling up to 25 miles downwind, and Anchorage has received a light dusting. Game McGimsey, Image courtesy of AVO/USGS.

Photograph of Redoubt Volcano in eruption taken during observation and gas data collection flight on March 31, 2009. View is to the east. Continuous emission of volcanic gas, water vapor, and ash is producing a plume rising to about 10,000 to 15,000 feet above sea level. AVO scientists observed ash falling up to 25 miles downwind, and Anchorage has received a light dusting. Game McGimsey, Image courtesy of AVO/USGS.

 View to the northwest of ash deposits on the upper Drift River valley and surrounding terrain from recent eruptions of Redoubt volcano. Game McGimsey, Image courtesy of AVO/USGS.

View to the northwest of ash deposits on the upper Drift River valley and surrounding terrain from recent eruptions of Redoubt volcano. Game McGimsey, Image courtesy of AVO/USGS.


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Nice bit of video assembled by Bretwood Higman from March 27. It consists of 15 sec stills framed up. The large explosion is the 7:25 (AKDT) eruption.

Redoubt Eruption March 27 2009 from Bretwood Higman on Vimeo.

Redoubts 1:40 pm, March 28 eruption, as captured by Dennis Anderson

Redoubt 15:29 eruption, 3/28/2009., courtesy Rick Monyahan

Lightning from Redoubt 11:20 pm, March 27, eruption, courtesy Bretwood Higman.

Lightning from Redoubt, 11:20 pm, March 27, eruption, courtesy of Bretwood Higman.

Redoubt volcano from the south over the ash-covered Crescent River Valley.

Redoubt volcano viewed from the south over the ash-covered Crescent River Valley.

March 26, 2009. Game McGimsey, Image courtesy AVO/USGS.

Some past events:

The April 4, 2009 eruption was one of the more dramatic eruptive events. This EWR composite shows the eruption as it appeared on radar:

“2009-03-27 01:59:09
Seismicity associated with the explosive series of eruptions that began at 11:47PM AKDT has tapered off to low-level tremor. The volcano remains restless and seismicity is still above background. The aviation color code remains at RED.” Alaska Volcano Observatory

ahg_20090327_0832_net

This scan from 08:32UTC shows Redoubt erupting. Echo Tops reports altitude to at least 45,000 feet (red). Ash cloud is moving eastward towards Kenai in subsequent scans: (09:33UTC):

ahg_20090327_0933_net

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