2009-03-25 05:53:13 - VAN/VONA
A small explosion occurred at Redoubt volcano at 05:12 AKDT (1312 UTC). The cloud height is estimated to be about 15,000 ft and is drifting north to northwest of the volcano. The event lasted about 10 minutes.
A small explosive event occurred at 10:17 AKDT this morning. The plume from this event was not detected by radar, indicating that it did not rise above approximately 12,000 ft asl or contained very little ash. This explosion triggered a flowage event on the north flank of the volcano as indicated by seismicity.
This event was similar to or smaller than the explosion that occurred this morning at 5:12 AKDT.
2009-03-25 13:35:06 - VAN/VONA
Seismic activity at Redoubt Volcano has declined over the last 36 hours, although there have been several brief increases in seismicity associated with minor low-level ash emissions. The last known ash emission was at 5:12 AKDT this morning. The plume from this event did not extend above about 15,000 feet. Based on the level of seismic activity, AVO is lowering the aviation color code to ORANGE and the volcanic alert level to WATCH.
Current seismicity at Redoubt is at times suggestive of intermittent lava extrusion at the volcano's summit. However, the existence of a new lava dome has not been confirmed because of poor weather. Growth of lava domes is common at volcanoes like Redoubt and was observed several times throughout the last eruption of 1989-1990. As dome size increases, so does the possibility of dome collapse along with a return to a more explosive eruptive style. Though a distinct rise in seismicity often precedes dome failure, domes can fail with little or no warning and may result in a sudden explosion and ash emission.
Based on observations from the Redoubt eruption of 1989-1990, episodes of dome growth followed by explosive dome destruction is a likely but by no means certain, near-term scenario. Cycles of dome growth and failure could occur for several months. In the event of an escalation in seismic activity or confirmation of a significant ash producing eruption, AVO would accordingly raise the color code and alert level to Red/Warning.
It is possible that dome collapse events will initiate pyroclastic flows over Drift glacier that will result in meltwater generation and downstream mudflows and floods. Some of these floods could reach Cook Inlet within hours.
A new explosive event at Redoubt has just taken place at approximately 8:34 AKDT. The NWS has detected a cloud height of about 30,000 feet based on radar. The Aviation Color Code is being raised to Red and the Volcano Alert Level to Warning.
2009-03-26 08:56:56 - VAN/VONA
AVO is raising the aviation color code to Red and the alert level to Warning at Redoubt volcano. An explosive event beginning at roughly 08:34 AKDT has produced an eruption cloud to at least 30,000 ft. above sea level. The event continues.
A major explosive event occurred at 09:24 AKDT. Pilot reports the cloud height to be at least 65,000 ft above sea level.
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ANCHORAGE AK
905 AM AKDT THU MAR 26 2009
THE NATIONAL WEATHER SERVICE IN ANCHORAGE HAS ISSUED A
* FLASH FLOOD WARNING FOR...
* UNTIL 300 PM AKDT
* DUE TO THE ERUPTION OF REDOUBT VOLCANO.
THE ERUPTION OF REDOUBT VOLCANO CAN CAUSE MELTING SNOW AND ICE ON
THE MOUNTAIN AND RESULT IN HIGH WATER AND FLASH FLOODING ALONG
DRIFT RIVER DRAINING FROM THE MOUNTAIN.
A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
2009-03-26 12:33:56 - Status Report
A large eruption of Redoubt volcano occurred at 09:24 AKDT (17:24 UTC) this morning. National Weather Service reports the cloud height to be at least 65,000 ft above sea level and pilot reports indicated a plume height of 60,000 ft. Since this event, a few smaller events have occurred but these did not generate plumes above about 20,000 feet.
The eruption at 9:24 AKDT also produced a lahar in the Drift River valley that was detected by seismic instruments.
An ashfall advisory is in effect until 4 PM for the western Kenai Peninsula. High level ash (above 30,000 feet) is forecast to pass over Anchorage, but is not expected to produce ash fall. For more information refer to the NWS Redoubt Coordination web page (pafc.arh.noaa.gov...) for latest ash cloud information.
AVO is monitoring the situation closely, the observatory is staffed 24/7, and attempts to overfly the volcano will occur as soon as possible. More details on this mornings eruption also will be released on AVO's web page as soon as possible.
Video clip with audio eruptions/explosion of Redoubt volcano, occurred on 2009/03/26 at 16:24 and 17:24 UTC. Footage is from the official Hut webcam. Playing speed is 80x realtime, sound is obtained from converted digital seismic traces of REF, RDN, RDT, DFR, NCT seismic stations. Lahars, pyroclastic flows and steaming from heated snow can be seen. Towards the end of this video (about minute 3:40) weather conditions start to clear up and the summit of the volcano becomes partially visible, revealing a column of gray ash.
Sound from RDN and REF stations has been denoised.
For audio spatiality, each station (channel) has been placed respectively, from the left to the right, in this order: NCT, RDN, DFR, REF, RDT. This partially reproduces their actual physical location.
Official statement from AVO regarding the start of these events:
"2009-03-26 08:56:56 - VAN/VONA
AVO is raising the aviation color code to Red and the alert level to Warning at Redoubt volcano. An explosive event beginning at roughly 08:34 AKDT has produced an eruption cloud to at least 30,000 ft. above sea level. The event continues."
Alaska Volcano Observatory website for updates: