Stratovolcano
eklemetti | March 27, 2009
Image courtesy of AVO/USGS by Game McGimsey
Following the provided script, Redoubt erupted again last night, producing a 32,000 foot / 10,000 meter ash column that prompted a new ash fall warning for the Kenai Peninsula area. Thus far, though, there have been few reports of major damage being caused by the ash fall. Alaska Air has yet to resume flights to Anchorage due to the ash, but will be reassessing as the day goes on. Since then, the seismicity has settled and we can wait for the next explosion. 2 PM Alaska time? Sounds good to me.
I want to point everyone to the great video montage…
eklemetti | March 25, 2009
Image courtesy of AVO/USGS. Taken by Cyrus Read
Based on the current levels of seismicity over the past 36 hours, AVO has returned Redoubt to Orange/Watch status from Red/Warning. This doesn't mean that the eruption is over, just that things have settled down a bit. Flights to and from Anchorage have resumed as well. You can read the full statement here, but the take-home messages are:
AVO expects this to be like the 1989-1990 dome-building eruptions, although no new dome magma has been seen yet (mostly thanks to poor weather).
Dome collapse will likely generate pyroclastic flows with…
eklemetti | March 25, 2009Redoubt seems to be setting its pattern for this part of the new eruptive period. There was another small explosion this morning that produced at 15,000 foot / 5,000 meter ash column that moved to the NNW. The seismicity has settled down since the early morning eruption today (3/25) as well.
These types of explosions producing plinian and subplinian eruption clouds that will likely lead to dome building - the same pattern seen at Mt. Saint Helens in 2004-2008 and the previous Redoubt eruptions in 1989-1990. These explosions, producing ash columns that reach tens of thousands feet, will likely…
eklemetti | March 24, 2009
Image by AVO/USGS/Game McGimsey, March 23, 2009
Redoubt has simmered down some today with no new eruptions since yesterday evening. AVO's field crew not only fixed the Hut webcam, but also spotted massive lahar deposits (see above) in the Drift River valley that traveled 35 kilometers downstream and have officials on local and national levels worried about the Drift River Oil Terminal. Funny, it sounds so familiar somehow? As usual, an ounce of planning and thought about locating an oil terminal at the foot of an active volcano would have prevented about 10 tons of problems now.
AVO will be…
eklemetti | March 24, 2009
Image courtesy of AVO/USGS
AVO has posted a series of images taken around Redoubt and around the Cook Inlet since the new eruptions started the night of March 22nd. You can begin to see the extent of the ash fall, what the explosions have done to the Drift Glacier and the new deposits in the Drift River valley. Most of the images show a lot of meltwater mudflows and tephra deposits on the slopes of the volcano. They've also added images from satellite and radar sources that show the initial dispersal of ash from the eruptions throughout the area north of Redoubt.
Eruptions reader Akira…
eklemetti | March 23, 2009The Hut webcam at Redoubt that has a great view of the hydrothermal vents near the 1989-90 domes - and the area where the current eruption is likely to be sourced - is back online. So far, we can see what looks like lahar deposits on the lower left-hand flanks of the volcano in the stream channels (likely formed by the melting of the Drift Glacier) and ash deposits all over the snow. Also, depending on the light and clouds, you can definitely see an ash column coming from the volcano.
Also, AVO is reporting that at 7:41 PM (Alaska time), a new ash column was spotted on radar reaching 60,000…
eklemetti | March 23, 2009
The Anchorage Daily News has a report that 16 Alaskan representatives got stuck in Anchorage after the eruption started. They were headed to Juneau to vote on Alaska accepting stimulus money ("volcano monitoring" anyone?), but they were on one of the many flights canceled by Alaska Airlines today due to the ash. ADN also have reports of an "ash out" in the coastal town of Skwentna.
AVO is currently reporting that ash doesn't appear on the current radar maps in the Cook Inlet and there are no reports of new ash fall. This suggests that the ash is either staying below 13,000 feet / 4,000…
eklemetti | March 23, 2009
Redoubt on 3/15/2009, from Eagle River overlooking Anchorage. Photo courtesy of Calvin Hall
I'm breaking this out of the comments of the "Redoubt Erupts!" post just to keep things up-to-date.
As of now, we know:
At least 5 explosions have occurred as part of the eruption
Ash has drifted to the NNE and W - both as seen on radar and as reports of ash falling in Skwentna and the Chuitna area - and so far missing populated areas (see above)
The ash cloud is believe to have reached as high as 50,000 feet/15,000 meters - prompting an aviation warning/restrictions and cancellation of flights out…
eklemetti | March 23, 2009
Mt. Redoubt in March 2009, prior to erupting
At ~10:30 PM (Alaskan Time) last night, Mt. Redoubt erupted. AVO and the Anchorage VAAC issued a Red Alert for ash as high as 50,000 feet (15,000 meters) around the volcano. Information is scarce about the exact nature of the ash cloud because of the fact that the volcano erupted at night. The eruption has contained at least 5 large explosion and at least one of the seismometers at the volcano has stopped reported (RSO). An ashfall advisory has been issued by the Weather Service, with ash predicted to fall throughout the Susitna Valley (which…
eklemetti | March 18, 2009
Image from AVO Hut webcam for Redoubt
After an exciting few days ... well, OK ... after an exciting few hours on Sunday, AVO has decided to lower the alert level at Redoubt in Alaska to Yellow/Advisory. The alert level was lowered last week after seismicity at the volcano returned to normal after weeks of rumbling (at Orange/Watch status), but then we are all caught by surprise when a phreatic explosion occurred (and AVO returned the volcano to Orange). However, this didn't lead to a new period of heightened seismicity, so back to Yellow we go (even with elevated gas emissions and a nice…
eklemetti | March 17, 2009
Now that Redoubt has decided that Yellow/Advisory is not to its likely and has returned to an Orange/Watch status, I'll continue bringing new updates of the volcano has events unfold.
And nothing much has unfolded since the phreatic explosion that occurred on Sunday. The current state of the volcano, according to AVO, is minor seismic unrest and that is about it. They do offer some more details of the events on Sunday:
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…
eklemetti | March 4, 2009
Folks have been suggesting that life on Earth started near volcanic vents for a long time now (and of course, some people don't buy it). Whether or not life sprung forth near hydrothermal vents, undersea black smokers or from the head of Zeus, it doesn't really change the fact that we find organisms living in these places today, expanding what we might consider "habitable" by leaps and bounds. Case and point, researchers from CU-Boulder have recently found a community of micro-organisms happily living near the summit of Volcán Socompa (above) in Chile in the hydrothermal vents. Now, having…
eklemetti | March 3, 2009
Count this as your mini-update for Redoubt, with the news being no news. Even AVO seems a little bored with Redoubt lately (not to say they aren't watching it as vigilantly as ever) as their last three updates have been exactly the same:
Redoubt volcano has not erupted. Seismicity is low, but above background levels and consists mainly of small discrete earthquakes. Night has fallen and no image is visible in the webcam.
However, down the road (arc-wise) in the Aleutians, AVO has raised the alert level at Okmok Caldera. New volcanic tremors were felt yesterday at Okmok, averaging about one…
eklemetti | February 28, 2009As there has been a lot of chatter about the goings-on at Redoubt, I thought I'd post the latest AVO update (3:35 PM):
Redoubt volcano has not erupted. Seismicity is dominated by small discrete earthquakes and tremor remains at the diminished levels of the past two days. Webcam images are now clear and show no change in the volcano.
Nothing doing. In fact, seems quieter than it has been in the last few weeks.
eklemetti | February 26, 2009The Redoubt watch is now been going for well over a month and this is how quickly things can change when monitoring volcanoes. The headline in my volcano RSS, when I saw it said:
"Redoubt quiets after weeks of activity, though eruption still possible"
By the time I clicked on the link, the headline for the KTUU TV article became:
"Redoubt steaming at strongest level, seismic activity calms"
The seismic event refered to happened yesterday afternoon (Alaska time) and the volcano rumbled for about an hour, getting picked up by seismometers all around the Cook Inlet. They also mention that steam…
eklemetti | February 24, 2009Not much new to report with Redoubt except that folks in Alaska are getting, well, a little punchy.
AVO currently reports (7:12 AM):
Volcanic tremor and occasional discrete earthquakes continue at Redoubt. Since 00:00 local time on 2/24, tremor amplitude at nearby stations has gradually increased, and the number of small earthquakes on nearby stations has increased slightly.
Redoubt isn't exactly making us volcanologists look too good lately. That is the nature of the beast, I suppose.
eklemetti | February 18, 2009
I found this little press release that doesn't have a huge amount of information, but is interesting nevertheless. The Coordinating Committee for Prediction of Volcanic Eruptions of Japan (nice name) is putting seven volcanoes on "24/7" monitoring. That sounds like we might see a lot of eruptions in Japan soon ... except that their rationale was that these volcanoes "are likely to affect public life by erupting or becoming active in the coming 100 years". That is quite the window of eruptive opportunity! The question is what exactly "24/7" monitoring - does this mean that someone/something…
eklemetti | February 18, 2009Not much to add to the Redoubt Watch this week. The volcano continuing to experience increased seismicity and AVO is watching it closely. Sounds like we'll be doing the same for the time being.
eklemetti | February 15, 2009
UPDATE 2/15/2009 20:30 PM: Marta Calvache of INGEOMINAS says that seismicity has all but stopped at Galeras after the eruption Saturday night, however the area will be kept on alert for more potential activity. However, even with the eruption, apparently there are very few people in the evacuation centers - never a good sign if something really big were to happen at the restless Colombian volcano. Â
Last night, Galeras, near Pasto in Colombia, erupted, prompting an evacuation of nearly 7,000 people living near the volcano. The first CNN article linked above, for some reason, says that…
eklemetti | February 13, 2009We've now had three weeks of waiting for Redoubt, and all we have to show for it is steam, seismicity and lots and lots of press. As of today, Redoubt continues with the same: elevated seismicity, constant monitoring, think it will erupt.
Current status from AVO:
Redoubt Volcano has not erupted. Elevated seismicity is continuing, dominated by ongoing volcanic tremor and occasional small earthquakes. A storm system is moving across the Redoubt area at present, which will make for poor viewing conditions today. Associated winds are causing a small increase in seismic amplitudes on some seismic…