Alaska
eklemetti | October 13, 2008
The eruption of Kasatochi was a bit of a surprise to volcanologists who study the Aleutians, to say the least. The volcano itself has been quiet for likely over 100 years, but with relatively little warning, the volcano erupted over the summer, blasting ash (and a large amount of sulfur dioxide) into the atmosphere. We finally have some images of the destruction wreaked upon the island, and from the looks of it, the island is blanketed in grey ash from the eruption(s). Biologist who have worked on the island prior to the eruption think a significant number of auklets may be buried in the ash…
eklemetti | October 4, 2008
Finally, after a rather quiet week, we have news that yet another Aleutian volcano is showing signs of potential activity. Redoubt Volcano was seen steaming away in a recent flight over the stratovolcano. When combined with reports of "booming noises" and the scent of sulfur it all points towards increased chance of eruption. However, AVO points out that they have not seen any increase in seismicity at Redoubt so far, making it difficult to predict exactly what the future will bring for the volcano. The volcano last erupted in 1990 and an eruption in 1989Â (above)Â produced a VEI 3 blast…
eklemetti | August 18, 2008
Sorry about the lack of update. Having no internet while moving will do that! I did see an email this morning that had some interesting information about the amount of sulfur dioxide emitted by Kasatochi (Alaska) during the current eruption (thanks to Simon Carn, UMBC):
"The August 7-8 eruption of Kasatochi volcano (Aleutian Islands)produced a very large stratospheric SO2 cloud - possibly the largest since the August 1991 eruption of Hudson (Chile). Preliminary SO2 mass calculations using Ozone Monitoring Instrument (OMI) data suggest a total SO2 burden of ~1.5 Tg. This figure will be…
eklemetti | August 14, 2008
This article sums up a lot of the events that led up to the Kasatochi (Alaska) eruption last week from the point of view of the biologists on the island itself right before it erupted. There are some great descriptions of the whole island shaking for 10 minutes, and they also offer some exciting new details such as this:
"Jeff Williams, a biologist for the maritime refuge, sailed by the island on the refuge boat the Tiglax and said the island has a new shape; what were steep cliffs rising from the ocean on the island's east and west sides now appear to be long, gradual slopes."
That would…
eklemetti | August 13, 2008
NASA posted a nice image of the ash plume from the current eruption at Kasatochi (Alaska) showing the brown/grey ash mixing with white clouds over the Pacific. Not much else to report on the eruption other than that AVOÂ reported that seismicity remained low from August 10-12.
eklemetti | August 11, 2008
The current eruption at Kasatochi is causing a lot of flight cancellations for flights from Alaska to points in the continental US. The ash is swirling its way around the Aleutians along flight lanes (see above), with the ash drifting southeast over the Alaska Panhandle and could hamper air travel in Alaska and Canada for days according to the USGS (although Alaska Air says it might start flying again later today). As for the eruption itself, not much new news beyond the initial impression that the volcano went from quiet to explosively erupting to produce at 35,000 foot (~10,000 meter) ash…
eklemetti | August 9, 2008
The folks up in Alaska have a lot to watch these days in the Aleutians, with three volcanoes erupting right now. Just a quick update on the current activity:
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Kasatochi: The eruption that started Thursday and produced 45,000 foot ash columns has quieted by Saturday, but there are still moderate (M=5) earthquakes being recorded near the island (above, before eruption).
Okmok: Ash from the month-long eruption is falling on islands near the caldera.
Cleveland: Activity at Cleveland has quieted to the point that no ash column was spotted on Saturday.
eklemetti | August 8, 2008
Just a quick update if you haven't been following the discussion: Kasatochi volcano in the Aleutians is now listed in "Red Alert" as it is erupting (see image above). Not many details beyond the typical description of ash columns, in this case reaching 45,000 feet, which is a pretty decent height. The Coast Guard warns of pumice rafts from the eruption, but it is hard to tell if it because they exist, or that it is just the generic warning for any eruption at sea. The two USFS biologists were evacuated before the eruption.
Edit 8/8/08: I'll add a link to the official USGS Press Release on…
eklemetti | August 7, 2008
The Okmok Caldera eruption is still going on, almost a month after it started. The latest USGS/SI Weekly Report states:Â
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Strong volcanic tremor on 2 August prompted AVO  to raise the Volcano Alert Level to Warning and the Aviation Color Code to Red. Cloudy conditions prevented satellite observations. Later that day, AVO geologists in the area reported that ash-and-steam plumes rose to minimum altitude of 6.1 km (20,000 ft) a.s.l. The seismicity decreased and the Volcano Alert Level was lowered to Watch and the Aviation Color Code was lowered to Orange. Observers in Ft. Glenn on Umnak…
eklemetti | August 7, 2008
Finally, in a very slow week for volcano news, we find a report from the Alaska Volcano Observatory about concerns of another eruption in the state. Currently, both Okmok and Cleveland are erupting, and now AVO has issued a warning about Kasatochi Volcano on the island of the same name (~100 kilometers east of Adak, roughly near 175W on the map above). The volcano is the island - more or less - and any people on the small island are being evacuated due to increased seismic activity underneath the volcano/island.
Not much is known about the eruptive activity at Kasatochi. The volcano does…
eklemetti | July 28, 2008
After raising the alert level at Okmok Caldera in Alaska to Red over the weekend, AVO has reduced it to Orange. Reports have the volcano producing ash columns of less than 20,000 feet versus the 35,000+ foot columns earlier in the weekend. At the same time, Cleveland Volcano is continuing to issue ash from the vent and signs are still there for a lava flow. Both of these volcanoes look like they should continuing erupting into the near future.
eklemetti | July 27, 2008
There haven't been any major developments volcano-wise over the weekend, just a few updates on some current rumblings:
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Soufriere Hills (Montserrat) coughed up more ash, producing ash columns to "thousands of feet" according to reports from the MVO. The eruptions/explosions were centered at the lava dome on the summit of the volcano, Seismicity has also increased, suggesting that a larger eruption might be in the works.
Chaiten continues to worry Chilean geologists. Although the eruption seems to have reduced in intensity over the weekend, the fear of a blockage that could lead to a…
eklemetti | July 25, 2008
The Alaska Volcano Observatory is reporting that both current eruptions in the Aleutians - at Okmok Caldera and Mount Cleveland - are showing signs of a lava extruding from the vent. Thermal anomalies have been imaged at the vents of both volcanoes, although no lava has been seen thus far. Both volcanoes continues to emit ash and steam.
The news that lava is erupting isn't really shocking (it is a volcano, you know). Many times, these eruptions begin with a "throat-clearing" phase of ash and volcanic debris being erupted from the vent. If the magma is still rising after these initial…
eklemetti | July 21, 2008
Just when you thought it was exciting enough in the Aleutians, word comes in that Cleveland Volcano is erupting as well. Cleveland is a very noisy volcano on Chuginadak Island, having last erupted in February (although it hasn't been updated on the GVP page). Aircraft have been warned about both eruptions in the Alaskan island chain. Along with the eruption of Okmok Caldera, the AVO has their hands full watching these volcanoes. The latest on Okmok has a 24,000 foot ash column continuing to be emitted from the new vent.
eklemetti | July 20, 2008
I'm back from my conference and will hopefully be getting back to a regular schedule!Â
In the meantime, the biggest news is still the eruption of Okmok Caldera in Alaska. The latest news has the eruption still going strong and the USGS predicting it will continues for potentially weeks to months. The eruption is apparently from a new vent on the caldera floor as well. Looks like the current eruption might be a VEI 4 (or thereabouts) eruption based on what I've heard from USGS scientists.Â
The largest hazard posed by Okmok right now is to air travel, this during a time when the Alaska…
eklemetti | July 15, 2008Here's a stunning shot of the current eruption at Okmok Caldera in Alaska (brought to us by National Geographic).
Personally, I think the best part is the fact that this was shot by an Alaska Airlines pilot! Talk about "to the right of the plane..." fodder.
eklemetti | July 14, 2008Sorry about the brevity of this update, but I'm exhausted.
From the Alaska Volcano Observatory (AVO):
At this time, based on AVO analysis of satellite data, ash is
continuing to erupt from a composite cinder and spatter cone called
Cone D in the eastern portion of the 6-mile wide caldera or crater of
Okmok. It appears that the eruption is very water-rich due to
interaction of rising magma with very shallow groundwater and
surficial water inside the caldera. We have few direct observations
into the caldera and details of the current event remain unknown.
The current activity differs in…
eklemetti | July 13, 2008
Sorry about the delay with updates, I am actually at a meeting filled with volcanologists (of all things), so updates might be a little sporadic.
A lot of news today about Okmok erupting in the Aleutians. The Alaska Volcano Observatory had this to say:
The eruption at Okmok continues based on high levels of seismicity and ash continues to be erupted as indicated in satellite observations. Seismicity reached a peak at about 2200 Z
(2:00 PM ADT) yesterday and has been gradually declining since. Reports from Unalaska indicate no ash fall in Unalaska/Dutch Harbor since last night. However,…
eklemetti | July 12, 2008
Okmok Caldera in Alaska's Aleutian Islands erupted today, sending an ash column to at least 30,000 feet. Very little news has been released about the eruption so far beyond this information about the eruption column and some bits about precursor seismicity. A number of flights to Unalaska Island were cancelled due to the eruption. I'll pass on more information when I get it.
Okmok is located near Dutch Harbor, Alaska and is a large shield volcano with two prominent calderas at the top. In fact, whenever I see pictures of the caldera, I am reminded of what Crater Lake (Oregon) might look…
greengabbro | July 11, 2008 Well, technically this is Friday tsunami blogging, but sometimes it's hard to tell the difference. Yesterday was the 50th anniversary of the 1958 Southeast Alaska earthquake and ensuing Lituya Bay megatsunami, a half-kilometer high wave which killed only a handful of people.
The earthquake happened on the Fairweather fault, a strike-slip fault which forms the main boundary between the Pacific and North American plates on the Alaska panhandle. Strike-slip earthquakes don't typically cause tsunamis directly - in a strike-slip event, the ground moves mostly horizontally, not vertically, so it…