[Bass (OP)]

Redoubt Volcano, approximately 250 km southwest of Anchorage Alaska, has been placed on a volcano watch by the Alaska Volcano Observatory due to increased activity during the past week.  Scientists expect a possible large, ash-cloud eruption in the near future.

http://www.avo.alaska.edu/activity/Redoubt.php

[DoctorBeaver]

How dangerous is it liable to be & what size area would be affected?

[Bass (OP)]

The likely effect would be from ash-fall, which will affect Anchorage, the Cook Inlet and the Kenai Peninsula.  Probably shut down air traffic in the region for a few days and ash-fall may cause problems for several weeks.

Potential ash-fall projections based on the height of the ash clouds can be found here:
http://www.arl.noaa.gov/READY_traj_alaska.php

[DoctorBeaver]

Could be worse.

[Bass (OP)]

Hopefully won't affect the Valdez oil termainal

[DoctorBeaver]

Is that the Drift River terminal?

[JimBob]

Nein, Mein Gutten Herren,

The Valdez Terminal is on the upper east end of Prince William Sound. The Drift River terminal is near Kenai, on the Cook Inlet southwest of Anchorage.

Aufwiedersehn,

JimBob

[DoctorBeaver]

Thanks, Jim

[paul.fr]

You can follow this on twitter, if you want to.
http://twitter.com/alaska_avo

[LeeE]

I noticed a small swarm of earthquakes around McKinley just recently; there's a good USGS plugin for GoogleEarth that shows semi-real time updates (every five mins, iirc), but Redoubt looks relatively quiet.

There's been an M 4.6 quake about 31 km NNW of Seattle in the last hour though.

[LeeE]

I've not been able to get in to AVO for a few days, probably due to the alert, but I've just managed it and the alert still seems to be current.  GoogleEarth still shows little activity there though.

The M4.5 (revised) near Seattle seems to have been a one-off.

[LeeE]

Hmm... there's still an alert on Redoubt, but it still seems much quieter than McKinley.

There's been a bit of a swarm running along the NW axis between Cobb and Burned Mountains in NE Sonoma County, Calif for a while now.

[LeeE]

Looks like it's started.

[JimBob]

Yep ...

Alaska's Mount Redoubt volcano erupted again Monday morning, the fifth eruption since coming back to life, the U.S. Geological Survey reported.

 Darkness and snow obscured the eruptions, which started at 10:38 p.m. Sunday (2:38 a.m. ET Monday). Subsequent eruptions occurred at 11:02 p.m., 12:14 a.m., 1:39 a.m. and 4:37 a.m. local time.

Redoubt was last active in 1989, when eruptions lasted for five months, USGS geophysicist John Power said at an early morning news conference Monday.

"We would expect Redoubt to have some level of explosive activity for the next weeks or months," Power said.

The alert level went to red, the highest level, when the eruptions began, according to the Alaska Volcano Observatory web page.

The USGS estimated the height of the eruption cloud at 50,000 feet and warned that mudflows were possible on the Drift and Crescent Rivers and ashfall was likely downwind from the volcano.

 Aviation has been affected, Power said.

"I understand a number of commercial flights have been canceled coming in and out of Anchorage International Airport," Power said. "We could see disruptions to air travel to south central Alaska, and Alaska as a whole, for a period of weeks to months."

Ash from the volcano is expected to blow north and pass west of Anchorage, said Dave Schneider, a geophysicist with the Alaska Volcano Observatory. He described the ash as a trace -- meaning if some landed on a windshield, the driver could still see through it.

Power said the ash will be about the thickness of a penny or a dime but warned residents to take precautions.

"It does pose significant problems for mechanical systems, people with respiratory illnesses, and aircraft," he said, adding that residents should be prepared to stay indoors.

Those in range of the ashfall should seal their windows and doors, the National Weather Service said. It also advised that residents protect electronics, minimize driving and cover air intakes and open water supplies.

Early Sunday, researchers had raised the monitoring status for the volcano, which had been showing increased seismic activity. Officials had predicted an eruption was possible "within days to weeks."

Officials have been monitoring Redoubt since July, Power said, and raised the aviation threat level to yellow in November and orange in January. The threat level alternated between orange and yellow until March 21, when it was last raised to orange, Power said.

 Bill Burton, a USGS geologist, said there had been increases in seismic activity at Mount Redoubt since January followed by periods of quiet.

The 10,197-foot peak is about 100 miles southwest of Anchorage, the most populous city in Alaska

--- CNN

It seems the USGS Alaska Volcano Observatory is trying to analyze data - not much recent information except the times and cloud height.

Latest - "The eruption of Mt. Redoubt continues. The height of the eruption cloud is estimated to be 50,000 ft above sea level. Further reports will be issued as more information becomes available." - Sunday, March 22, 2009, 11:26 PM AKDT (20090322/0726Z)

---- http://www.avo.alaska.edu/activity/Redoubt.php

[paul.fr]

Alaskans deal with fallout from volcano ash
Interior secretary warns activity could continue for weeks or months

 [ Invalid Attachment ]

updated 10:53 a.m. ET March 24, 2009
WILLOW, Alaska - Rita Jackson said she was taking a sip of coffee when she tasted something funny on her lips — ash.

Alaska’s Mount Redoubt’s first cluster of eruptions in nearly 20 years — a total of six were detected between Sunday night and Monday night — sent a volcanic ash plume more than 9 miles into the air and down into nooks and crannies.

Ash missed the state’s largest city, but dusted small communities north of Anchorage. The National Weather Service had an ash advisory in effect until 5 a.m. Tuesday for the Susitna Valley. There were no reported injuries.


The wind took ash away from Anchorage, toward Willow and Talkeetna, near Mount McKinley, North America’s largest mountain.

Jackson, in Willow, was experiencing other effects, in addition to ruined coffee. “My eyes are itching really bad,” she said as she hurried to get out of a grocery store to drape protective blue tarps over a motorcycle, snowmobile and vehicles.

The Alaska Volcano Observatory reports that the sixth eruption came at 7:41 p.m. Monday. The five earlier eruptions came late Sunday night into Monday morning.

Pattern could last for months
"We expect the pattern of this event to be similar to the 1989 and 1990 eruptions, and the activity could continue along those lines for several weeks or several months," said U.S. Secretary of the Interior Ken Salazar on a telephone conference call from Washington D.C.

Alaskans had been warned of a pending eruption of the volcano about 100 miles southwest of Anchorage since it became restless in late January. People stocked up on masks, air filters and disaster supplies.

 
J. Bell / AP
Map locates the Redoubt volcano near Anchorage, Alaska
--------------------------------------------------------------------------------
 
Eight Australians on a backcountry tour holed up in Shell Lake Lodge near Skwentna, about 100 miles northwest of Anchorage, waiting for the ash to settle.

“It’s a good half inch, it’s a pretty heavy dusting,” Craig Saunders, a Palmer man leading the group on an eight-day snowmobile tour of the Alaska wilds, said Monday.

Ash from Alaska’s volcanoes is like a rock fragment with jagged edges and has been used as an industrial abrasive. It can injure skin, eyes and breathing passages.

The young, the elderly and people with respiratory problems are especially susceptible to ash-related health problems. Ash can also cause damage engines in planes, cars and other vehicles.

“Anyone with a pre-existing respiratory problem is advised to stay indoors until the ash settles. If you do need to go out, a mask is recommended,” said Dr. Jay Butler, chief medical officer for the state of Alaska.


Click for related content
Alaskans brace for volcanic eruption
Q&A on Mount Redoubt's volatility

Air traffic affected
Some flights were canceled, leaving some state senators unable to fly into Juneau, and delaying consideration of a resolution accepting federal stimulus funds. Elmendorf Air Force Base in Anchorage kept 60 planes, including fighter jets, cargo aircraft and a 747 commercial plane, in shelters.

Small planes also could be affected. Barry Stanley, owner of Denali Flying Service in Willow, canceled three flights flying supplies to the Finger Lake area west of Willow on Monday because of the ash.

 INTERACTIVE

 Dangerous volcanoes
Learn more about eight of the world’s most dangerous volcanoes.
 
“You can’t fly in this stuff,” he said. “Ash is too risky to risk damaging your equipment. I’m not making money if I ruin my stuff.”

Jackson, 56, got an unexpected day off when her employer told her to stay home. She said that if she had time to walk her 7-year-old dog, Lola, “I’ll put her motorcycle goggles on her.”

Some residents didn’t even notice the ash at first.

“I just thought it was snow,” said Pat Walsh, who moved to Trapper Creek near Talkeetna after retiring as a police officer in Tucson, Ariz.

Plane nearly crashed last time
The 10,200-foot Redoubt Volcano, roughly 100 miles southwest of Anchorage, last erupted during a four-month period from 1989-90.

In its last eruption, Redoubt sent ash 150 miles away into the path of a KLM jet and its four engines flamed out. The jet dropped more than 2 miles before the crew was able to restart all engines and land safely. The plane required $80 million in repairs.

The volcano became restless earlier this year. The observatory had warned in late January that an eruption could occur at any time.

Increased earthquake activity over the past 48 hours prompted scientists to raise the alert level for Mount Redoubt on Sunday.

On Sunday morning, 40 to 50 earthquakes were being recorded every hour.

A steam plume rising about 1,000 feet above the mountain peak was observed Saturday.

Three seismometers on the mountain were damaged in the eruption but seven others remained in place, said observatory geophysicist John Power.

Power said the history of past eruptions of Redoubt indicate the volcano could erupt again in the next few days or weeks.

"It's something we need to stay prepared for," he said.

http://www.msnbc.msn.com/id/29859859/

[JimBob]

Not to be outdone by Bass -

2009-03-27 13:04:43
Seismicity at Redoubt has decreased following the explosive eruption this morning at 8:40 AKDT. Small discrete earthquakes are occurring at a relatively low rate.

For ash fall information from recent events please refer to the National Weather Service Redoubt Coordination web page http://pafc.arh.noaa.gov/volcano.php

2009-03-27 11:40:29
Seismicity at Redoubt has decreased following the explosive eruption this morning at 8:40 AKDT. Small discrete earthquakes are occurring at a relatively low rate.

For ash fall information from recent events please refer to the National Weather Service Redoubt Coordination web page http://pafc.arh.noaa.gov/volcano.php

2009-03-27 08:59:59
The explosive event from this morning at 840 AKDT has ended and ash movement as seen in radar is to the north.

For ash fall information, refer to the National Weather Service Redoubt Coordination web page http://pafc.arh.noaa.gov/volcano.php

AVO is monitoring the situation closely, the observatory is staffed 24/7.

2009-03-27 08:46:03
An intense seismic signal indicates that another explosive event began at about 08:40 AM. The event is showing up on several networks. The ash plume is just showing up on radar. Cloud heights TBD since it is still climbing.

2009-03-27 07:33:53
Seismicity has become more continuous over the past 30 minutes. No ash visible on radar yet. We are watching this current event closely.

More ...
2009-03-27 06:12:35
A pulse of tremor that started about a half hour ago is currently diminishing. NWS saw nothing on radar associated with it.

Check the National Weather Service site for ash advisories:
http://pafc.arh.noaa.gov/volcano.php

2009-03-27 05:20:55
Seismicity associated with the explosions that began at 11:47 PM AKDT has tapered off to discrete events. We have not yet received any reports of ash fall associated with this event. The aviation color code remains at RED.

Check the National Weather Service site for ash advisories:
http://pafc.arh.noaa.gov/volcano.php

2009-03-27 04:05:00
Seismicity associated with the explosive series of eruptions that began at 11:47PM AKDT has tapered off to low-level tremor over the last three hours. The volcano remains restless and seismicity is still above background. The aviation color code remains at RED.

Check the National Weather Service site for ash advisories:
http://pafc.arh.noaa.gov/volcano.php

2009-03-27 03:01:22
Seismicity associated with the explosive series of eruptions that began at 11:47PM AKDT has tapered off to low-level tremor over the last two hours. The volcano remains restless and seismicity is still above background. The aviation color code remains at RED.

Check the National Weather Service site for ash advisories:
http://pafc.arh.noaa.gov/volcano.php

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.

Check the National Weather Service site for ash advisories:
http://pafc.arh.noaa.gov/volcano.php

2009-03-27 00:55:24
An explosive series of eruptions that began at 11:47PM AKDT continue.

Check the National Weather Service site for ash advisories:
http://pafc.arh.noaa.gov/volcano.php

2009-03-27 00:15:31
An eruption of Redoubt volcano began at about 11:47pm AKDT, March 26. National weather service radar indicates a cloud height of about 38,000 ft above sea level.

2009-03-26 23:44:58
An intense seismic signal indicates that another explosive event began at about 08:40 AM. The ash plume is just showing up on radar. Cloud heights TBD since it is still climbing.

2009-03-26 23:29:25
Seismicity continues to increase in intensity.

There has not been a large explosion of ash into the atmosphere since this morning's eruption at 9:24AM.

The observatory remains staffed 24 hours a day

[JimBob]

Anchorage airport remains closed today as a result of heavy ash fall from Redoubt volcano. Air quality is so bad that breathing masks are being worn by the residents to protect against silicosis. Ash clouds were blown over  50,000 feet into the atmosphere.

All pictures from Anchorage Daily News - http://www.adn.com/ (Front Page, March 28, '09) Views of the site after this date will not have any of the 100 of these pictures available, so I have selected 4 from yesterday's eruption that were published today, below.

Two spectacular pictures from last night - volcanic eruptions are quite often accompanied by lightning





Earlier in the day as eruption began:



Eruption has been under way for several hours

[LeeE]

Very good series of pics - thanks for posting.