Alaska - Mt Redoubt Volcano could erupt within days

A few pics:
[atsimg]http://files.abovetopsecret.com/images/member/91c5fe5c4b0a
[atsimg]http://files.abovetopsecret.com/images/member/badc04c0d609.jpg[/atsimg]
[atsimg]http://files.abovetopsecret.com/images/member/f646ffa512c4.jpg[/atsimg]

and another:

[atsimg]http://files.abovetopsecret.com/images/member/363efb63fb29.jpg[/atsimg]

[edit on 16-3-2009 by Elostone]

[edit on 16-3-2009 by Elostone]

[edit on 16-3-2009 by Elostone]

[edit on 16-3-2009 by Elostone]

New information statement from AVO:

Current Status and Observations
Seismic activity at Mount Redoubt increased at about 1:05 AKDT Sunday afternoon (March 15, 2009) and approximately 4 hours of continuous volcanic tremor ensued. The onset of the tremor was associated with a small explosion that produced a plume of gas and ash that rose to about 15,000 feet above sea level and deposited a trace amount of ash over the summit-crater floor and down the south flank of the volcano to about 3,000 feet. AVO responded to this increase in activity by raising the color code and alert level to ORANGE/WATCH at 2:50 PM AKDT. At this time it does not appear that the increase in activity heralds a significant eruption in the short term, but conditions may evolve rapidly.

An AVO overflight Sunday witnessed activity from 11:30 AM until about 3:00 PM and was able to document ash emission from a new vent, just south of the 1990 lava dome and west of the prominent ice collapse feature near the north edge of the summit crater. Although ash emission was short lived, it represents the first documented ash fall during the current episode of unrest at Mount Redoubt.

About twenty minutes after the initial steam and ash burst, a sediment-laden flow occurred from a small area in the ice at about 7000 feet on upper Drift glacier. This flow descended about 1500 feet and produced a distinctive seismic signature seen across the Redoubt network.

Although the intent of the overflight was make airborne gas measurements, only a few such measurements were possible due to the uncertain nature of the activity and potential for further ash emission. The measurements that were made indicated at least a qualitative increase in SO2 emission relative to levels measured previously. The gas data are currently being processed and will be available soon.

Interpretation of New Activity and Possible Outcomes
Although preliminary, it is likely that the plume observed just after 1:00 PM AKDT on Sunday, March 15, 2009 was produced by a steam explosion in the shallow hydrothermal system of the volcano. Without examination of the ash we cannot say with certainty if the ash represents new magma or if it is merely pulverized old material from the surface of the volcano.

Steam-driven explosions are not unexpected events at Redoubt given the amount of heat that is being released at the surface. It is possible that more such explosions can occur with little or no warning. It is possible that these plumes can reach above 20,000 feet, and may contain minor amounts of fine ash.

Relatively rapid increases in seismic activity, and an overall waxing and waning pattern to the seismicity at Redoubt may persist for weeks to months. Increases in seismicity may or may not be associated with other volcanic phenomena, such as minor ash emission, and vigorous steaming. The burst of activity at Redoubt on March 15, 2009 indicates that the volcano is still in a restless condition.

AVO plans to visit Redoubt later this week to attempt collection of ash samples, retrieve GPS data and do some routine maintenance of seismic and other equipment.

AVO has resumed 24 hour per day staffing of the AVO operations center in Anchorage.

I was right then when I said that the seismic signature of the new burst of activity was in my opinion similar to that of a mud/debris flow. There has been one, but on a flank of the volcano unseen from webcams (Drift Glacier).

[edit on 2009/3/16 by Shirakawa]

reply to post by Shirakawa


I thought they took it down pretty hasitly. A few days of quietness and they took it down. Considering there is a volcanoe erupting for a hundred years, a few days break is only a milisecond in geological time.

I have a feeling it is gonna get quite busy here soon.

[atsimg]http://files.abovetopsecret.com/images/member/821f6da647d0.jpg[/atsimg]

North face of Redoubt Volcano about 35 minutes after the ash burst of March 15, 2009. Dark ash stripe on crater floor visible behind ongoing vigorous vapor and gas plume emanating through the glacial ice. The dark stripe in foreground is a watery debris flow that emerged from beneath the ice about 20 minutes after the ash event.
Picture Date: March 15, 2009 13:39:36 AKST


Image Creator: Neal, Christina; Bleick, Heather;


Image courtesy of AVO/USGS.

Redoubt alert color code lowered to YELLOW:

2009-03-18 09:41:36 - VAN/VONA
The Alaska Volcano Observatory is lowering the Aviation Color Code to YELLOW and the Alert Level to Advisory for Mount Redoubt. Following the steam and ash emission on Sunday, March 15, seismicity has declined to levels prior to that event, and no additional emissions have been observed in web camera or satellite images. The new magma beneath the volcano does not show signs of upward movement at this time. The volcano remains restless with abnormally high rates of gas emission and continued melting of the summit glacier. It is still possible for the current period of unrest to result in an eruption. However, the type of unrest we have observed so far could persist for many months to a year or more and not lead to an eruption. It is possible for conditions at the volcano to change rapidly, advancing from relatively low levels of activity to eruption in time periods as short as 24 hours or less.

AVO will continue to monitor Redoubt closely, but will no longer be formally staffed 24 hours per day.

Originally posted by Shirakawa
Redoubt alert color code lowered to YELLOW:

2009-03-18 09:41:36 - VAN/VONA
The Alaska Volcano Observatory is lowering the Aviation Color Code to YELLOW and the Alert Level to Advisory for Mount Redoubt. Following the steam and ash emission on Sunday, March 15, seismicity has declined to levels prior to that event, and no additional emissions have been observed in web camera or satellite images. The new magma beneath the volcano does not show signs of upward movement at this time. The volcano remains restless with abnormally high rates of gas emission and continued melting of the summit glacier. It is still possible for the current period of unrest to result in an eruption. However, the type of unrest we have observed so far could persist for many months to a year or more and not lead to an eruption. It is possible for conditions at the volcano to change rapidly, advancing from relatively low levels of activity to eruption in time periods as short as 24 hours or less.

AVO will continue to monitor Redoubt closely, but will no longer be formally staffed



24 hours per day.

unhuh okes

In the last 30 minutes seismicity at Redoubt increased very slightly, and judging by the trace spectrum from RSO seismic station, I'd say that at the moment a small debris flow or stronger than before steam/ash emission is in progress.
Too bad that webcams are obscured for the night.

Originally posted by Shirakawa
In the last 30 minutes seismicity at Redoubt increased very slightly, and judging by the trace spectrum from RSO seismic station, I'd say that at the moment a small debris flow or stronger than before steam/ash emission is in progress.
Too bad that webcams are obscured for the night.

so in your opinion them lowing it to yellow again is a mistake?

That depends.

In my opinion, at the moment sismicity is higher than when AVO lowered the aviation color code to Yellow earlier this month, and it looks like it's slowly increasing over time. Steam emission from the summit of the volcano also seems stronger than in past months, with a higher and denser plume than before.

My guess is that they're forced by internal protocols/policies to lower the aviation color code if the volcano doesn't show clear signs of potentially hazardous unrest. I'm sure they're still monitoring it 24/7, though, and will raise alert codes if proper conditions occur.

On the RSOE map there is an earthquake symbol right over the Volcano one but the preliminary report says there isn't a volcano within 100km. Where is Kokhanok in relation to Mt Redoubt?

EDIS Number EQ-20090318-145173-US
Common Alerting Protocol Magnitude 3.1 (Minor)
Date-Time [UTC] 18 March, 2009 at 21:04:13 UTC
Local Date/Time Thursday, March 19, 2009 at 12:04 in the moorning at epicenter Location 59.5808 -154.7344 Depth 7.10 km (4.41 miles)
Listing volcanos in 100 km of radius: There is not a volcano in 100 km of radius.

LINK

reply to post by Maya00a


Redoubt is 158 Km (about 99 miles) far from Kokhanok.
There are a few other surrounding historically active volcanoes.

[atsimg]http://files.abovetopsecret.com/files/4064e3741e29d9ae.jpg[/atsimg]

[edit on 2009/3/19 by Shirakawa]

reply to post by Shirakawa


you could be right, which is prob the smae reason no one in their right mind would evr rasie YS color code from green its too frighting. but i t hink YS should always been on yellow. but thats just my opinion.

Have you seen the webcams?
It isn't very clear as at the moment the volcano is covered with clouds, but it seems to me that the steam plume is much higher than ever. I'll try to make a slideshow later to be sure of this, if the weather will clear a bit.

EDIT: seismicity has also increased a little, maybe the heightened plume is a direct effect.

[edit on 2009/3/19 by Shirakawa]

What I think was a phreatic (steam) explosion occurred at 10:18 UTC and was felt by multiple seismic stations around Redoubt volcano.

Weekly update from AVO:

ALASKA VOLCANO OBSERVATORY WEEKLY UPDATE
Friday, March 20, 2009 12:02 PM AKDT (Friday, March 20, 2009 20:02 UTC)


REDOUBT VOLCANO (CAVW #1103-03-)
60°29'7" N 152°44'38" W, Summit Elevation 10197 ft (3108 m)
Current Aviation Color Code: YELLOW
Current Volcano Alert Level: ADVISORY

On Sunday, March 15, 2009, AVO raised the color code and alert level to ORANGE/Warning during an abrupt increase in seismicity and following a burst of steam and ash that was observed by airborne AVO staff. High volcanic gas emissions were measured during the event. After several hours, seismicity and steam emissions declined, and remained low for the next several days. The color code and alert level was subsequently reduced to YELLOW/Advisory on March 18, 2009.

Seismic activity at Redoubt has been low over the remainder of the week but remains above background levels. The seismicity consists of occasional short periods of low amplitude volcanic tremor and small discrete earthquakes. A burst of several dozen larger events occurred Friday morning.

Mostly clear weather at the volcano this week has provided good satellite and web camera images, and these showed nothing unusual. A steam plume rising just above the summit of the volcano has been visible most of the week.

It is still possible for unrest at the volcano to change rapidly, and seismic activity or other signs of unrest could escalate over time periods as short as 24 hours or less. AVO continues to monitor Redoubt closely, but the AVO operations center in Anchorage is no longer formally staffed 24 hours per day, although someone is on duty 24 hours per day and can be contacted by calling 907-786-7497.

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 international air traffic and resulted in minor or trace amounts of ash in the city of Anchorage and other nearby communities.

Gettin' pretty bumpy tonight at Redoubt... RSO Webicorder

New magma flowing? Cracking rocks? Seems like they really need to keep Redoubt at Orange due to its erradict behavior. I'm sure their budgets aren't fitting in too much time for it nowadays.

reply to post by SpadeofAces


To me it looks like new magma is rising to the summit of the volcano:
- Frequent shallow earthquakes of amplitude greater than in past days
- Marked increase of earthquakes having a certain spectrum trace (I asked the AVO staff more details on this and they said they're investigating as they're not sure if it's volcanic or due to instrumentation problem)
- Chaotic tremor appears to have changed to (very) low amplitude harmonic tremor during the last hours, though this is only my suggestion
- Seeing the RSAM charts, seismicity is increasing slowly over time
- As webcams have showed these days, steaming from vents on the summit of the volcano is dense and continuous

[edit on 2009/3/21 by Shirakawa]

New information statement from AVO:

2009-03-21 08:50:16 - Information Statement
Shallow earthquake activity under the volcano that began yesterday continues, at times approaching one event per minute. Activity is primarily seen on the stations nearest the summit, though some events are also recorded at farther-out stations. A steam plume rising approximately a thousand feet above the volcano is visible on the Cook Inlet Redoubt web camera, but no explosive or ash activity such as occured last Sunday has been identified. AVO is watching the activity closely but remaining at Yellow/Advisory at this time.

It is still possible for unrest at the volcano to change rapidly, and seismic activity or other signs of unrest could escalate over time periods as short as 24 hours or less. Minor explosive activity such as was seen March 15 could occur with little or no warning.

A field crew is scheduled to install another seismometer at the volcano today.

reply to post by Shirakawa


The thing about the steam plumes is I am gonna guess that a lot could be atmospheric. The colder it is, the larger they are. Much like when you breathe on a cold day and can see your breath.