Alaska - Mt Redoubt Volcano could erupt within days

A very big event occurred 5 minutes ago (20:13:30 UTC), but I'm not sure if it's a big earthquake or not. We'll know more in the next few minutes,

EDIT: it looks like a strong local earthquake to me. No eruption, but it could trigger further volcanic events.

EDIT2: it probably was this 4.7 magnitude earthquake located 20 miles north from Anchorage: earthquake.usgs.gov...

EDIT3: the earthquake probably triggered a very small rockfall at redoubt, nothing to be concerned about.

[edit on 2009/4/7 by Shirakawa]

yea it was, sounded like a freight train but only shook for a few seconds.. Thought it was going to be a biggy but wrong again, perhaps in the next week or so :-) (jk)..

This is interesting:

2009 Redoubt Eruption: Update and Prognosis, Saturday April 11, 2009
Link from AVO

RSO seismic station has finally been fixed. Now it's transmitting data properly. It's the best station among those near the summit of the volcano in my opinion!

Today's status report from AVO. It has not changed much since those of the last days:

2009-04-16 11:48:26 - Status Report
The eruption of Redoubt volcano continues. Seismic data over the past day is indicative of continued lava dome growth. Clear views in today's web camera show a vigorous steam and gas plume emanating from the vent area.

AVO has a field crew en route to the volcano to make observations and do maintenance on equipment. Airborne gas measurements also will be made on a separate mission later today.

Additional significant explosive events with accompanying ash clouds, ash fall, and mudflows are possible and can occur with little or no warning. AVO will maintain 24/7 operations in order to quickly detect renewed significant explosive activity and other hazardous phenomena.

Please see the National Weather Service Redoubt coordination page pafc.arh.noaa.gov... for the latest ash fall information.

[edit on 2009/4/16 by Shirakawa]

A new Hut webcam has been installed!
Check out here

2009-04-16 15:43:10
The 2009 eruption of Redoubt continues. Clear weather allows web cameras and satellites to view a vigorous steam plume, possibly containing minor ash, and rising up to 16,000 feet according to pilot reports. Low-level seismicity continues and a lava dome is growing in the vent. Plume conditions this afternoon allow views of the base of the north side of the dome. NOTE: NEW WEBCAM IMAGE AVAILABLE--SEE BELOW.

The volcano remains at aviation color code ORANGE and alert level WATCH. The potential for renewed explosive activity is high and may resume with little warning, likely generating an ash plume and a lahar.

AVO has a field crew working at the volcano today to make observations and do maintenance on equipment. Airborne gas measurements are being made concurrently. NEW WEBCAM. A field crew installed a new camera with zoom capability at the Hut site north of the volcano. At present the image is at maximum zoom and it shows a nice view of the blocky, growing lava dome perched at the head of the canyon below the crater.

I have selected a few pictures from the new Hut webcam to show the growth of the blocky lava dome over time at Redoubt. Missing days are when the view was obscured by clouds:

April 16: i42.tinypic.com...
April 20: i44.tinypic.com...
April 21: i43.tinypic.com...
April 22: i44.tinypic.com...



[edit on 2009/4/23 by Shirakawa]

Weekly update from AVO:

2009-04-24 16:02:23 - Weekly Update
The 2009 eruption of Redoubt Volcano continues. During the past week, growth of the lava dome within the summit crater has slowed based on observations of little change in dome shape. Using a Radarsat2 image from April 20 and thermal images obtained on April 16, the current dome is estimated to be about 500 m (1640 ft) by 700 m (2297 ft) and 150 m (500 ft) thick. Emissions of volcanic gases and minor amounts of ash continues. A probable rockfall from the lava dome generated a very localized dusting of ash early today. The aviation color code remains ORANGE and the alert level WATCH. AVO continues to monitor the situation closely and the observatory is staffed 24/7.

The last explosive event during the current eruption occurred on the morning of April 4 (05:55 AKDT). Since then, seismicity has remained elevated above background reflecting the ongoing process of dome growth and occasional rock falls. The nearly constant vapor and gas cloud rising above the volcano has remained mostly below 15,000 feet above sea level. Satellite images show thermal anomalies at the summit as well as the low -level plumes and sulfur dioxide clouds drifting away from the volcano. Airborne gas measurements on April 20 indicate that emission of sulfur dioxide and carbon dioxide has increased since the previous measurement on April 16.

On Tuesday, April 21, an AVO field crew repaired a GPS station at the research hut (webcam location) that had been damaged in the March 23 explosion. In addition, they retrieved data cards from other GPS stations and the Dumbbell Hills time lapse camera. AVO geologists sampled material from the last explosive event and lahar deposits in the Drift River Valley. Additionally, high-water marks were measured from the flow down Drift River on April 4. The flow averaged about 10 m (33 ft) in depth at mid-valley.

The current Redoubt eruption is expected to continue for weeks to months. During this time, a cycle of relatively quiet periods of lava dome growth followed by explosive episodes of dome destruction will likely take place. Future explosions pose an ongoing threat of lahars in the Drift River Valley, trace to minor ash fall throughout south-central Alaska, and ash-related impacts to aviation.

Heavily ice-mantled Redoubt volcano is located on the western side of Cook Inlet, 170 km (106 mi) southwest of Anchorage and 82 km (51 mi) west of Kenai, within Lake Clark National Park. Redoubt is a stratovolcano which rises to 10,197 feet above sea level. Recent eruptions occurred in 1902, 1966-68, and 1989-90. The 1989-90 eruption produced mudflows, or lahars, that traveled down the Drift River and partially flooded the Drift River Oil Terminal facility. The ash plumes produced by the 1989-90 eruption affected aviation and resulted in minor or trace amounts of ash in the city of Anchorage and other nearby communities.

Weekly update from AVO

2009-05-01 14:50:15 - Weekly Update
The 2009 eruption of Redoubt Volcano continues. During the past week, growth of the lava dome within the summit crater was confirmed by changes in the shape and size of the dome. Seismic activity remains elevated above background levels reflecting the ongoing process of dome growth and occasional rock falls and avalanches of hot blocks. Satellite images show persistent thermal anomalies, consistent with an actively growing lava dome in the summit crater. Occasional small rock avalanches from the lava dome have produced minor ash emissions in the immediate vicinity of the volcano. Such rock fall events have been observed in the Hut web camera and one was observed directly yesterday, by an AVO field crew, while at the camera station.

Clear web camera views this week have also shown a consistent gas and steam plume rising to about the summit of the volcano. Airborne gas measurements on April 28 indicate that emission of sulfur dioxide and carbon dioxide remain elevated and similar to previous measurements.

On Thursday April 30, AVO geologists sampled ash-fall deposits and worked on lahar deposits in the mid and lower Drift River Valley. Dome temperature measurements were made using a forward looking infrared (FLIR) camera and those data are being processed. In addition, the field crew retrieved and replaced data cards from three GPS stations.


The current Redoubt eruption is expected to continue for weeks to months. During this time, a cycle of relatively quiet periods of lava dome growth followed by explosive episodes of dome destruction will likely take place. Future explosions pose an ongoing threat of lahars in the Drift River Valley, trace to minor ash fall throughout south-central Alaska, and ash-related impacts to aviation. AVO is maintaining 24/7 operations in order to quickly detect renewed significant explosive activity and other hazardous phenomena.

I made a timelapse video of the growth and change over two weeks of time of the lava dome on the summit of Redoubt Volcano. HD version available if you click on the video:

Long and detailed information statement from AVO:

2009-05-02 09:48:22 - Information Statement
2009 Redoubt Eruption: Update and Prognosis, Saturday, May 2, 2009

Summary

The 2009 eruption of Redoubt Volcano continues. The last major explosion at Redoubt occurred at 05:55 AKDT April 4. Since then, a lava dome has been growing in the northern part of the summit crater. The shape of the dome when viewed from above is elliptical, with the long axis oriented approximately north-south. A tongue of lava that forms the northern tip of the dome has advanced about 550 yards (500 m) down the Drift Glacier Gorge. The volume of the dome as of early May is approximately 25 - 30 million cubic meters. Renewed explosive activity remains a possibility, and could occur with little or no warning. Such activity would likely result in ash plumes exceeding 30,000 feet (9000 m) above sea level, lahars down the Drift River Valley, and trace to minor ash fall on communities near Redoubt. [...]

Full text here

Personal (not official from AVO) observation:

In the last few hours there has been a slight increase of activity in the form of a multitude of similar small repeating signals, denoting extrusion of lava from the growing dome at a rate higher than in past days, but not unprecedented in this 2009 eruption.

This change of activity is visible from RSO and REF (slightly) webicorders.

[edit on 2009/5/3 by Shirakawa]

Latest Volcano Activity Notification (VAN) from AVO:

2009-05-05 06:59:43 - VAN/VONA
Current activity at Redoubt volcano suggests that a significant explosive event is likely, though not certain, in the coming days. This event could occur at any time with little or no warning. Since about May 2 shallow earthquake activity beneath the actively growing lava dome of Redoubt volcano has been slowly increasing. The growing lava dome is becoming increasingly unstable.

Should a significant explosion occur, the event will likely produce high altitude (>30,000 ft ASL) ash plumes, trace to minor ash fall in parts of south-central Alaska, lahars in the Drift River Valley, and pyroclastic flows in the immediate vicinity of the volcano.

AVO continues 24/7 operations and is monitoring the situation closely. AVO will provide frequent updates of the volcano's status and the earliest possible warning of significant explosive activity and other hazardous phenomena.

Almost about to erupt again:

Update from AVO

2009-05-05 22:31:11
Since about 9:58PM AKDT this evening, seismicity at Redoubt has changed from discrete, repeating events, to continuous tremor. Small ash bursts are sending ash to less than 12,000 feet above sea level. Winds are carrying the low-level ash and steam plume towards the east. We will continue to monitor this evolving situation closely.

[edit on 2009/5/6 by Shirakawa]

Weekly update:

2009-05-08 15:17:14 - Weekly Update
Growth of the lava dome continued this past week and is now roughly equivalent in size to the largest dome that was emplaced during the 1989-90 eruption. As the dome grows larger it is increasingly unstable with a growing likelihood of a complete or partial dome failure. Currently AVO considers renewed explosive activity and dome destruction as the most likely outcome of the current episode of dome growth. The return to explosive behavior may occur with little or no advanced warning and would produce a significant ash cloud and lahars and/or flooding in the Drift River valley. There is also a possibility that the current episode of dome growth will slowly diminish and no further explosive activity will occur. Based on our knowledge of past eruptions at Redoubt AVO considers this outcome to be less likely.

Seismicity has varied in its frequency, magnitude, and source characteristics over the past week, but remains consistent with continued dome growth. Numerous rock falls off the unstable north flank of the dome have been observed in seismic and web camera images this week, and have produced minor ash plumes that have reached heights of 12,000 ft above sea level (several thousand feet above the volcano). Vigorous venting of steam and other volcanic gases has been observed, and broad regions of sulfur dioxide gas have been detected by airborne gas measurement flights and in satellite images extending for hundreds of miles from the volcano. Thermal anomalies related to dome growth were observed in satellite data throughout the week.

AVO is monitoring the situation closely and the observatory is staffed 24/7. AVO will provide frequent updates of the volcano's status and the earliest possible warning of significant explosive activity and other hazardous phenomena.

Weekly update from AVO:

2009-05-15 14:19:15 - Weekly Update
The 2009 eruption of Redoubt continues and is characterized by slow growth of the lava dome in the summit crater, continued high gas output, and elevated seismicity. Seismic activity over the past week has declined from the levels seen from May 2-7, but remains above background levels. Small rock avalanches, discrete earthquakes and minor volcanic tremor have been evident in seismic data throughout the week. The lava dome continues to grow as new magma reaches the surface. Incandescence at the dome has been observed in nighttime images from the hut web camera, and thermal anomalies have been persistent in mostly clear satellite views of the summit most of the week. The lava dome is now about 30 to 60 million cubic meters (about 40 to 80 million cubic yards) in volume, and is extending slightly down the upper Drift glacier canyon. The dome has been visible in web camera images throughout the week, and typically shows a robust steam plume rising from the southern part of the dome base. Rock avalanches also have been observed in web camera images. The avalanches typically generate small diffuse ash plumes that linger in the vicinity of the summit crater, but otherwise are not detected in radar or satellite data. Growing lava domes associated with steep terrain may become gravitationally unstable and can collapse with little or no precursory seismicity. If the lava dome in the summit crater does collapse, or is removed by a sudden explosive event, significant ash emissions, possibly to more than 30,000 feet above sea level, and trace to minor ash fall on communities in south-central Alaska are likely. Pyroclastic flows associated with dome collapse or removal also may develop, and if they sweep across snow and ice on and around Drift glacier, they could initiate lahars and floods in the Drift River valley.

Although the level of unrest has not changed significantly over the past week, the apparent lull in activity does not indicate that the eruption is ending. Gas emissions remain very high, and effusion of lava and slow growth of the lava dome continue. Explosive activity could resume before the level of unrest declines and the eruption ends.

AVO is monitoring Redoubt volcano closely and the observatory is staffed 24/7. AVO will provide frequent updates of the volcano's status and the earliest possible warning of significant explosive activity and other hazardous phenomena.

New information statement from AVO. Long but interesting and explains in detail the recent volcano developments!

2009-05-26 11:22:42 - Information Statement
Summary

The 2009 eruption of Redoubt Volcano has entered its 10th week. Lava continues to erupt from a vent in the summit crater feeding a blocky, rubbly lava dome that extends out of the summit crater and more than 500 m (1640 ft) down the north flank of the volcano. Although volcanic seismicity has declined somewhat in the last few weeks, it remains elevated above pre-eruption background. Volcanic gas emissions also remain elevated. The growing lava dome is potentially unstable and the possibility of a full or partial collapse remains high. Such a collapse would likely be accompanied by a large ash plume and lahars in the Drift River Valley. This event could occur with little or no warning. Consequently, AVO continues to monitor the volcano 24 hours per day and the aviation color code remains ORANGE and the alert level WATCH.

Recent Observations

The current lava dome is estimated to be roughly 40 million cubic meters in volume based on analyses of thermal and satellite images and aerial photographs. This amount of material would fill approximately 11 Louisiana Superdomes. Using measurements from a Worldview satellite image on May 17, the dome and tongue of lava that extends to the north is about 950 m (3115 ft) long (north-to-south), 460 m (1510 ft) wide (east-to-west), and 200 m (655 ft) tall. Over time, the dome is growing in size primarily to the north but to the east and west as well. There is a slight overhang developing at the very front (northernmost part) of the lava tongue in the upper Drift gorge.

Nighttime images from the AVO webcam continue to show occasional incandescence or glow as rockfalls expose hot interior dome rock. Thermal images obtained during helicopter overflights indicate portions of the surface of the lava dome exceed 350 degrees C. This value reflects the temperature of the cooling crust and is not a direct measurement of actual lava temperature as it emerges from the vent. Temperatures of fresh lava of this composition should be considerably higher (~850 to 950 degrees C).

Seismic activity at Mount Redoubt remains elevated with numerous small volcanic earthquakes and signals from small rock avalanches recorded on the stations closest to the volcano. Many of these small rock falls generate minor ash plumes that may rise several thousand feet above the crater rim and produce localized fallout.

Airborne gas measurements over the past several weeks indicate that Redoubt's emissions remain high. For the month of May, preliminary calculations indicate that average emissions are in excess of 8,000 tonnes/day of SO2 and 15,000 tonnes/day of CO2 . These values are similar to the range of values measured during the early dome building phase of the 1989-90 Redoubt eruption and are consistent with strong degassing expected during active lava extrusion.

Reviewing data on erupted lava composition, seismicity, and deformation (as measured by high-precision GPS measurements made in the vicinity of the volcano), AVO scientists infer that magmas feeding the lava dome are rising from at least two main staging locations at 3 to 5 km (2-3 mi) depth below the surface and 8 to more than 15 km (5-9 mi) depth. The processes of magma ascent and eruption have produced a variety of mixed andesitic magmas sampled by AVO since the start of the eruption in March.

Prognosis and Ongoing Hazards

The last explosive event of the current eruption occurred on the morning of April 4 destroying the lava dome that had grown in the summit crater in late March and early April. The current lava dome has now been growing for 53 days and is similar in size to the larger domes emplaced during the 1989-90 eruption. During the 1989-90 eruption, the longest period of dome growth between explosions was 36 days. Based on the size of the current lava dome and the likelihood of increasing instability as it extends down the steep upper Drift gorge, AVO expects it will most likely be destroyed either through gravitational collapse or an explosion from within the shallow vent system.

The Redoubt eruption is expected to continue for additional weeks to months. During this time, a cycle of relatively quiet periods of lava dome growth followed by brief explosive episodes of dome destruction will likely take place. Future explosions pose an ongoing threat of lahars in the Drift River Valley, trace to minor ash fall throughout south-central Alaska, and ash-related impacts to aviation. However, the possibility remains that the lava dome growth rate may slowly diminish and the dome itself will stabilize and no further explosive activity will occur.

For more information and recent photographs including animations of dome growth, please see our web site: www.avo.alaska.edu...

Weekly update from AVO

2009-05-29 14:41:44 - Weekly Update
The 2009 Redoubt eruption continues. Small discrete earthquakes and rockfall signals in the summit region have been recorded steadily over the course of the past week. Poor weather has obscured frequent views of the summit since Monday and it is difficult to evaluate the degree of change at the dome this week. Gas emissions measured on Monday showed a steep decline since last measured on May 14. Additional measurements are scheduled for early next week.

Since the last explosion at Redoubt on April 4, the lava dome has extended slowly down the steep north slope of the volcano. Additional explosions are still possible. In addition, this large mass of hot lava could fail in an avalanche with little or no warning. Either event could send ash over 30,000 feet above sea level, produce lahars in the Drift River valley, and deposit trace to minor amounts of ash on communities in south-central Alaska.

AVO continues to monitor Redoubt volcano closely and the operations center in Anchorage is staffed 24/7. AVO will provide frequent updates of the volcano's status and the earliest possible warning of significant explosive activity and other hazardous phenomena.

[edit on 2009/5/29 by Shirakawa]

Weekly update from AVO

2009-06-05 13:35:29 - Weekly Update
The 2009 eruption of Redoubt volcano continues. Seismic activity this week has remained low, and is comprised of small, discrete events associated with the growing lava dome. The extended dome now reaches more than 950 meters down the north flank of the volcano. This large mass of fresh lava remains unstable and could fail with little or no warning, leading to significant ash emissions and possible lahars in the Drift River valley. Rockfall activity continues from the edges of the dome, resulting in occasional minor ash deposits in the summit region.

Conditions at the volcano have been mostly cloudy during the week, obscuring satellite and webcam views. The occasional clear webcam view showed continued steaming from the summit. No ash signals have been observed in satellite or radar imagery.

Field crews made three trips to Redoubt this week to collect gas samples, make dome observations, and investigate debris flow deposits in the Drift River valley. Gas emission data are still being processed.

AVO continues to monitor Redoubt's activity 24/7. AVO will provide frequent updates of the volcano's status and the earliest possible warning of significant explosive activity and other hazardous phenomena.

Weekly update from AVO:

2009-06-12 14:30:42 - Weekly Update
The 2009 eruption of Redoubt volcano continues. Seismicity has been low during the past week, but remains above background level. Seismicity is primarily comprised of small, discrete events associated with continued growth and instability of the lava dome.

The lava dome is now approximately 1000 m in length, 460 m in width, and 200 m tall. Recent data suggest that the rate of dome growth may be slowing. This large mass of fresh lava remains unstable and could fail with little or no warning, leading to significant ash production and possible lahars in the Drift River valley.

Clear webcam images earlier this week showed continued steam and gas emissions from the volcano. Current cloudy weather at the summit obscures webcam views. No ash signals have been observed in satellite or radar imagery.

Significant field work was carried out at Redoubt this week, including four flights to measure volcanic gas emissions, three days of deformation related field measurements, maintenance of Redoubt's seismic network, aerial photography and thermal imagery of the dome.

AVO continues to monitor Redoubt's activity 24/7. AVO will provide frequent updates of the volcano's status and the earliest possible warning of significant explosive activity and other hazards.

Weekly update:

2009-06-19 12:28:40 - Weekly Update
The 2009 eruption of Redoubt volcano continues. Seismicity has been low during the past week, but remains above background level. Seismicity is primarily comprised of small, discrete events associated with continued growth and instability of the lava dome.

Cloudy conditions have obscured most webcam and satellite images this week. Mostly clear webcam images today show continued steam and gas emissions from the dome. No ash signals have been observed in satellite or radar imagery.

Poor weather conditions throughout the week limited field work opportunities. One field crew was able to measure gas emissions from the plume and briefly observe the dome on Monday, June 15. The lava dome is now approximately 1,000 m in length, 460 m in width, and 200 m tall. Data suggest that the rate of dome growth may be slowing. This large mass of fresh lava remains unstable and could fail with little or no warning, leading to significant ash production and possible lahars in the Drift River valley.

AVO continues to monitor Redoubt's activity 24/7. AVO will provide frequent updates of the volcano's status and the earliest possible warning of significant explosive activity and other hazards.