Alaska
eklemetti | March 25, 2009Image 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 little…
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, 2009Image 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, 2009Image 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, 2009Mt. 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 22, 2009Seismicity has increased dramatically at Redoubt in Alaska over the last 24 hours, so AVO has put the volcano back on Orange/ Watch status. They say the tremors being felt now could be signs to an impending eruption (days to weeks), especially after the other events of the past week. Stay tuned! (Pardon the briefness, I'm posting from my iPod.)
eklemetti | March 18, 2009Image 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 14, 2009I missed this the first time, but Click & Clack from NPR's Car Talk answered a question about how to volcano-proof your car.
If you want to hear it, click here. As usual, the guys in Cambridge (our fair city) do an excellent job with the information and the humor.
{Hat tip to Jen Glass at Arizona State}
eklemetti | March 14, 2009Photo: The north flank of Mount Redoubt in early February 2009. Credit: Chris Waythomas / Alaska Volcano Observatory/U.S. Geological Survey
I've been following the waxing and waning of activity at Mt. Redoubt in Alaska for the past two months like many of you have. For a time there, the volcano had the nation's attention, both from the threat of a eruption near major shipping and oil hubs and from some questionable comments made by a certain Republican governor. However, nature sometimes doesn't play well with others, so after weeks of the Alaska Volcano Observatory's warnings that the…
sb admin | March 12, 2009
Welcome to version 2.0 of Eruptions, the blog on volcanic eruptions and volcano research in general. I've been writing this blog (starting over on Wordpress) over the last year or so, but now it has found a new home here at ScienceBlogs. If you're wondering what to expect if you're new to Eruptions, I'll be bringing news of volcanoes that are erupting worldwide, distilling the scientific jargon, dispelling the misinformation and commenting on what the effects of the eruption(s) might be. I'll also try to bring in any volcanoes in the popular media that gets my attention (alas, it has been…
eklemetti | March 10, 2009
AVO has officially downgraded the status at Redoubt from "Watch" (orange) to "Advisory" (yellow). The seismicity at the volcano has dropped off for the last couple weeks and signs that an eruption was imminent have waned. This, again, shows the difficulty in trying to predict the behavior of a volcano. All the signs were there at Redoubt - increased seismicity, increased heat flow at the summit (seen as melting ice and increased fumarolic output), increased volcanic gases (CO2 and SO2) - but as of right now, it seems like these signs only pointed to magma moving up the system, but not out of…
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 23, 2009Nothing much to report on the Redoubt front except more of the same. The latest report from AVO says (6:44 AM):
Redoubt Volcano has not erupted. Volcanic tremor and intermittent discrete earthquakes continue. Data for the past few hours (since 00:00 AST on 2/23) has consisted almost entirely of low-level tremor, with few discrete earthquakes.
So, it seems that Redoubt continues on its holding pattern. In other fronts, the Anchorage Daily News is running a good synopsis of the monitoring AVO does on volcanoes in the Aleutian chain in Alaska. More updates as seen fit.
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.