volcanic hazards
eklemetti | March 31, 2009
Photo courtesy of Calvin Hall. Taken from March 28, 2009, 50 miles from Redoubt.
Redoubt continues to huff and puff, with an almost constant ash plume of ~15,000 feet / 5,000 meters. This after ~4 PM (Alaska Time), an explosion produced a 25,000 foot / 8,000 meter ash column that disrupted flights in and out of Anchorage again. Also, the air in the Kenai Peninsula area is beginning to feel the effects of the eruption, as AVO notes:
Satellite images from this morning show a broad layer of volcanic haze extending east of the volcano over the Kenai Peninsula, the Anchorage Bowl, and the…
eklemetti | March 31, 2009Yellowstone Lake eruption, April 1, 2009
Well, after all the seismicity and uplift at Yellowstone caldera over the last few years, something finally happened. Early this morning, without much warning, an eruption occurred in Yellowstone Lake (see above) and sent steam and ash up 50,000 feet above the park. Luckily, no one was injured or killed in the event as we're well ahead tourist season, but it is unknown how this might affect access to the park for this summer.
Now, whether this eruption is really just the caldera "letting off steam" so to speak, possibly in the form of a phreatic…
eklemetti | March 30, 2009Image courtesy of the Southern California Earthquake Center
I have to admit, I've only been perpherially following the earthquake swarm currently going on in Southern California, near the end of one of the strands of the San Andreas fault out below the Salton Sea (see the bottom of the map above). The "Bombay Beach" swarm (as I'll call it ... beats me what most people are calling it) is being closely monitored by the USGS. However, from what I had heard from a friend of mine with a more structure/tectonics background, looked like tectonic quakes with "beachball focal mechanism solutions" that…
eklemetti | March 30, 2009Goma after the 2002 Eruption of Nyiragongo
The activity at Redoubt has captivated a lot of us, but in the grand scheme of things, its eruption are more likely to caused inconvenience and property damage rather than dramatically loss of life (unless something huge and unexpected occurs). However, the same cannot be said if Nyiragongo and/or Nyamuragira (a.k.a. Nyamulagira) in the Congo were to erupt. These volcanoes are close to the city of Goma, a city of nearly 600,000, not including refugees from the fighting in the region. Eruptions of Nyiragongo in 2002 prompted the displacement of 400,…
eklemetti | March 30, 2009Image courtesy of AVO/USGS by Tricia Joy Sadler. Taken 3/28/2009 at 3:29 PM
Redoubt did not stray from its pattern of explosive eruptions producing >20,000 foot / 10,000 meter ash columns over the weekend. However, what did change was the wind, and because of that, Anchorage began to feel the effects of the volcano. Ash prompted the closure of Ted Stevens International Airport in Anchorage for 22 hours on Saturday and Sunday. The airports near Redoubt are still experiencing delays and closure due to ash - remember, remobilized ash can be a problem as well, but many have reopened after ash…
eklemetti | March 27, 2009Image courtesy of AVO/USGS by Ron Beck. Shows an ash plume from Redoubt (tan) on March 26 from a Landsat 5 satellite.
I'll be "off the grid" for the weekend at a wedding, so I thought I'd leave this open for any Redoubt news Eruptions readers hear over the weekend. Feel free to leave comments about the developments up in Alaska.
Currently, AVO reports that seismicity is lower since the eruptions this morning. They indicate that eruptions will likely occur without warning from here on in.
There are also some new articles on how the eruption is affecting air travel, including cancellations of…
eklemetti | March 27, 2009Image 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 26, 2009Image courtesy of AVO/USGS, taken 3/23/09
I don't have many details, but the largest eruption so far in this eruptive stage at Redoubt occurred at 9:24 AM (Alaska Time), producing a 65,000 foot / 20,000 meter ash column! Yes, you read that right, a 20-km ash column! This is by far the largest ash column so far and AVO has returned Redoubt to Red/Warning status after this and a small explosion that occurred 30 minutes before the big one. Depending on the winds at various elevations, this sort of large ash column could threaten to coat Anchorage with ash - check the latest NOAA warnings here…
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, 2009Its been a busy week for volcanoes between the headline capturing Tongan and Alaska eruptions. Catch up on what you might have missed with the latest SI/USGS Weekly Volcano Report (for 3/18-3/24). Highlights (beyond Hunga Tonga Hunga Ha'apai and Redoubt) include:
Galeras, Colombia has settled down a bit
More block-and-ash flows from the two dome complexes growing at Chaiten, Chile
Strombolian eruptions at Mt. Etna, Italy
Plumes of steam and minor ash were reported from Popocatépetl, Mexico
A small lahar was seen at Tungurahua, Ecuador
Ash plumes and incandescent tephra explosions were…
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, 2009Mauna Loa fire fountains in 1984
For those of you looking for some non-Redoubt-related volcano news, you can take a look at the 25th anniversary of the last eruption at Mauna Loa (there is some nice video footage provided by KHNL if you follow the link). By no means is this volcano "dormant", but rather this is a typical lull in activity at the Hawaiian shield volcano. Its neighbor, Kilauea, has been erupting for decades, but the last major eruption at Mauna Loa was in 1984, when the volcano sent lava downslope with 3,000 feet of Hilo, moving 15 miles in a few days. Monitoring at Mauna Loa…
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 20, 2009
So, as I am apt to do from time to time, I was wandering the interweb and stumbled across the FEMA (Federal Emergency Management Agency) for Kids website. Naturally, I thought, what do they have to say about, oh, I don't know, volcanoes. Well, was I in for a doozy!
FEMA, in its infinite wisdom, has this to say about volcanoes (for kids, mind you):
[A] volcano is a mountain that opens downward to a pool of molten rock below the surface of the earth.
Oh. My. Word ... but wait, there's more!
The ash can cause damage to the lungs of older people, babies and people with respiratory problems.
Yes…