Alaska - Mt Redoubt Volcano could erupt within days

reply to post by jrod


I'd wait a few more days before saying that an eruption is not imminent anymore, or at least while the volcano status is still orange/watch.
Activity has seemed to stop a couple times in the past 45 days. This is a chart of seismic activity I posted earlier in this thread. Look between the dates 01/25 and 02/08:



[edit on 2009/3/2 by Shirakawa]

From AVO:

Redoubt volcano has not erupted. Seismicity is low, but above background levels and consists mainly of small discrete earthquakes.

Clear webcam images this afternoon/evening show nicely-formed, changing cloud over the summit which appears to be atmospheric. Otherwise we see no changes at the volcano.

AVO continues to monitor Redoubt closely and the observatory is staffed 24 hours a day.

This is the cloud:

Weekly update from AVO:

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

Redoubt Volcano remains in a restless state. The level of seismic activity has declined somewhat this week but is still above background levels. Seismic activity consists of small discrete earthquakes, and little to no volcanic tremor. There have been no significant earthquake swarms over the past week, and no new hydrologic or glaciologic events related to ice melt have occurred. Clouds have obscured views of the volcano by web camera and satellite most of the week.

AVO continues to monitor Redoubt closely and the observatory will be staffed 24 hours per day while the volcano is at an elevated level of unrest.

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.

Redoubt Aviation Code lowered to YELLOW:

From AVO:

2009-03-10 09:56:59 - VAN/VONA
The Alaska Volcano Observatory is lowering the Aviation Color Code to YELLOW and the Alert Level to Advisory for Mount Redoubt. The new magma beneath the volcano does not show any signs of upward movement at this time. The volcano remains restless with abnormally high gas emission rates and melting of the summit glacier still evident. It is still quite possible, though far from certain, that the current volcanic unrest at Mount Redoubt could result in an eruption. Also, this unrest could persist for many months to a year or more and not lead to an eruption. During this unrest, it is possible for unrest at the volcano to change rapidly, advancing from relatively low levels 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.

[edit on 2009/3/10 by Shirakawa]

Down to yellow, huh?

Well it hasn't lived up to my thread title! They did keep saying within hours, then weeks, then minutes ... back to weeks, then months .. now a year? They also evacuated elmondorf AFB, wonder if they returned to base?

Thanks for all your updates.

[edit on 11-3-2009 by violet]

I think they don't really know if Redoubt will erupt or not.
They say the unrest could escalate to an eruption in as little as 24 hours, to as long as one year, but also settle back to background activity without erupting anymore. They couldn't be more generic than this!

Despite the Aviation color code lowered to yellow, seismic activity at redoubt has become very interesting during the last two hours. It seems to me that tremors started again, and at least from what I hear in the audio files converted from seismic traces, I don't think I have ever heard anything like this in the last few weeks.

EDIT: forget that, all back to normal, it seems, at least for now.

[edit on 2009/3/11 by Shirakawa]

Originally posted by Shirakawa
Despite the Aviation color code lowered to yellow, seismic activity at redoubt has become very interesting during the last two hours. It seems to me that tremors started again, and at least from what I hear in the audio files converted from seismic traces, I don't think I have ever heard anything like this in the last few weeks.

EDIT: forget that, all back to normal, it seems, at least for now.

[edit on 2009/3/11 by Shirakawa]

could you please provide a link to that audio files for redout thanks....

yeah im bored

Well its seems Kīlauea has been quite busy if anyone wants to see some action.

And on the more boring sides, seems Helen went completely asleep.

Here's the file:

Download link

(1.8 MB, 80x speed)
This section is from 17:30-20:30 UTC

Background tremors slowly grow like something boiling up to minute 1:50, when a few strange little earthquakes occur in fast sequence and, after being followed by another one, they suddenly go back to the previous low levels of past days.

Extra: as I'm writing, a deep (86 Km) 3.3 magnitude earthquake occurred 45 kilometers away from Redoubt volcano, maybe it could be related.

acording to gee redout just had three quakes in the last 30 min from 2.4 to 3.0

Bad visibility atm for both of the webcams too...

Redoubt Hut Webcam

Redoubt CI Webcam

Too bad it's not visible in the obscured webcams and that now that Redoubt is on Yellow color code, updates are only daily and not every two hours, but judging by the activity occurred during the last hour, I think a mudflow is ongoing.

That 3.0 was 21 miles WNW of Clam Gulch. That is not Redoubt. That puts it in the water NW of Redoubt about 20 miles I think.

The sensor at the peak does look pretty active however. Those darn Seismo's are probably at Chilkoot Charlies getting drunk. Or they are at The Bush Company doing lord knows what.

Hear this other sudden event (in my opinion probably another mudflow) which started today at 12:50 UTC:

Download link
(80x speed)

[edit on 2009/3/12 by Shirakawa]

Information Statement from AVO. This is very detailed!

Current Status
On the basis of declining seismicity, a possible decrease in heat flux, and no apparent change in gas emission, the likelihood of an eruption of Mount Redoubt within days to weeks has diminished. Accordingly, AVO lowered the alert level to YELLOW/ADVISORY on Tuesday, March 10, 2009, and ceased round the clock staffing of the AVO operations center. The volcano remains on a heightened monitoring schedule, and AVO scientists will continue to evaluate conditions at the volcano regularly. The volcano remains restless and it is still possible, though far from certain, that the current episode of volcanic unrest at Mount Redoubt could result in an eruption.

Over the past two weeks the overall level of seismic activity has decreased, and the periods of sustained volcanic tremor, common during late January and most of February, have been largely absent. Discrete earthquakes are still occurring, but they are typically small and their observed rate is similar to that detected prior to this period of unrest. Volcanic gas emissions are still well above background levels, and melting of the upper Drift glacier in the vicinity of the 1989-90 eruption vent is continuing. These conditions could persist for many months and do not indicate that an eruption is imminent. It remains possible for conditions at the volcano to change rapidly, advancing from relatively low levels of unrest to eruption in time periods as short as 24 hours. If this happens, seismic activity should increase markedly providing some advance warning. At the present time, the overall trend is one of declining unrest and a much lower probability of an eruption in the near term.

Continues here.

More from the latest Information Statement

Analysis of Unrest
The current episode of unrest is most likely a result of intrusion of new magma beneath the volcano. The main evidence for an influx of new magma is: (1) measurement of significant amounts of magmatic gas, including CO2, SO2, and H2S from fumaroles in the vicinity of the 1989-90 vent; (2) increased heat flux causing ice/snow melt of the upper Drift glacier (about 4-5 million cubic meters through March 10, 2009), and fluctuating water discharge from streams draining the lower Drift glacier, (3) elevated seismicity since January 23, 2009, including hour-long periods of continuous volcanic tremor that is consistent with the movement of fluids (including heated ground water) and gases within the volcano. The influx of magma and rise of hot magmatic gases resulted in a reinvigoration of the volcano's hydrothermal system and this activity was likely the cause of some of the shallow seismicity. The increased heat output caused melting and disruption of snow and ice on Drift glacier and this led to greater than normal water outflow and at least one sediment-water outburst flood on Drift glacier.

Although we do not know how much new magma has intruded beneath Mount Redoubt, we estimate that most of the new magma is probably at depths greater than about 5 km (about 3 miles). It is possible that a small amount of the magma may have risen to shallower depths in late January-February when seismicity, degassing, and melting intensified. There is no evidence indicating a large volume of magma is present at shallow depths (within 2 km, or about a mile, of the surface).

On the basis of reduced seismic activity, it appears that the new magma intruded beneath the volcano is no longer moving toward the surface, or is doing so at a greatly reduced rate. Thus the probability of an eruption of Mount Redoubt within days to weeks is low. The volcano remains in a restless condition and it is still plausible that the unrest observed thus far will lead to an eruption on a longer time scale. We expect that elevated levels of volcanic gas emission and additional melting of the upper Drift glacier will continue for some time, perhaps many months.

Potential Future Activity
Redoubt is an active volcano and future eruptions are a certainty. The 1989-90 eruption was seismically monitored, but little was known about the seismic behavior of the volcano prior to that eruption. It is uncertain if future activity will be more or less like that of 1989-90. In 1989, seismic activity escalated rapidly, and explosive events occurred after only about 24 hours of precursory seismicity. During the current unrest, the sudden onset of strong volcanic tremor on January 25, 2009 was preceded by about two days of elevated seismicity, and the tremor indicated an eruption of Redoubt appeared likely. The activity observed thus far is distinctly unlike the activity that preceded the 1989-90 eruption, and has implications for future unrest and possible eruptive behavior.

Based on our observations and understanding of Redoubt Volcano to date, AVO considers the following scenarios as possible outcomes of the current period of unrest.

Gradual decline in earthquake activity, gas emission, and heat output, and return to normal background conditions. Occasional periods of slightly elevated activity that abates. Period of unrest ends, no eruption occurs.
After a period of relative quiescence, lasting some weeks to months, seismic activity increases, possibly rapidly, and the possibility of an eruption becomes more likely. The increase in seismicity likely would be accompanied by increasing volcanic gas emission, snow and ice melt, and increased melt-water runoff. If this situation arises, the following outcomes are plausible:

a. Hydrothermal system becomes invigorated, and this increases the possibility of phreatic activity (water related steam emissions or steam explosions), or explosive phreatic eruption. This could lead to magmatic involvement and an explosive magmatic or phreatomagmatic eruption.

b. Explosive eruption occurs, associated with rapid assent of magma to shallow levels. Activity could be similar to that of 1989-90 and may occur after a brief period of precursory seismicity, possibly as short as 24 hours.

c. Hydrothermal system becomes invigorated as it did in January-February, 2009, but again does not culminate in eruptive activity.

At present, AVO regards both scenarios 1 and 2 as about equally likely, and gives equal relative probability to scenarios 2a, 2b, and 2c should conditions evolve toward scenario 2. There are several examples worldwide of an explosive eruption occurring many months to more than a year following the onset of increased heat output. In fact, the 1966 eruptions of Redoubt occurred a year following the onset of increased steaming observed at the summit.

Ongoing Hazards at Current Level of Unrest
Heat and volcanic gas output could gradually decline over the coming months. However, parts of upper Drift glacier were disturbed by melting, and readjustment of the glacier will occur over time. Rapid settling of the ice could initiate sudden onset, fast moving and potentially hazardous outflows of water and sediment in the drainages adjacent to and downstream of Drift glacier. It is possible that settling of the ice may also initiate ice and rock avalanches, or unusual water flow on the surface of Drift glacier. These flows of water and or ice would be hazardous to anyone on Drift glacier or along its outflow streams.

If the hydrothermal system remains active for some time, additional melting, ice collapse, and minor downstream flooding should be expected. It is also possible that stream-driven (phreatic) explosions may occur without warning and it is possible for such explosions to produce plumes (possibly containing fine rock fragments) that could rise well above the summit of the volcano. Volcanic gas emissions are likely to continue for some months, and sulfur odors could be noted by people in the region. The output of volcanic gas will likely decline, but emission rates could be variable. During low wind conditions, potentially hazardous levels of gas could accumulate in low lying areas in the Drift glacier drainage.

Redoubt appears to be steaming more than I have ever seen during the last three months:



[edit on 2009/3/12 by Shirakawa]

Weekly update from AVO

ALASKA VOLCANO OBSERVATORY WEEKLY UPDATE
Friday, March 13, 2009 2:09 PM AKDT (Friday, March 13, 2009 22:09 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 Tuesday, March 10, 2009, AVO lowered the color code and alert level to yellow/advisory on the basis of declining seismcity, heat output, and no significant change in gas emission. An information statement describing the current status of the volcano and potential for future activity was released yesterday.

Seismic activity at Redoubt has been low over the past week but remains above background levels. The seismicity consists of occasional short periods of low amplitude volcanic tremor and small discrete earthquakes interspersed between periods of no seismic activity.

It has been cloudy over the volcano most of the week and only a few clear views were possible by satellite and web camera, and these showed nothing unusual. Yesterday afternoon, a steam plume rising just above the summit of the volcano was visible by web camera.

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.

Originally posted by Shirakawa
Weekly update from AVO

ALASKA VOLCANO OBSERVATORY WEEKLY UPDATE
Friday, March 13, 2009 2:09 PM AKDT (Friday, March 13, 2009 22:09 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 Tuesday, March 10, 2009, AVO lowered the color code and alert level to yellow/advisory on the basis of declining seismcity, heat output, and no significant change in gas emission. An information statement describing the current status of the volcano and potential for future activity was released yesterday.

Seismic activity at Redoubt has been low over the past week but remains above background levels. The seismicity consists of occasional short periods of low amplitude volcanic tremor and small discrete earthquakes interspersed between periods of no seismic activity.

It has been cloudy over the volcano most of the week and only a few clear views were possible by satellite and web camera, and these showed nothing unusual. Yesterday afternoon, a steam plume rising just above the summit of the volcano was visible by web camera.

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.

OMG WTf they just contridicted themselfs , AVO is no longer staffed 247 but there is somebody there 24 7 if anything changes .
yeah