remote sensing
eklemetti | April 5, 2009Image courtesy of AVO/USGS by Cindy Koplin showing the ash fall in Homer, AK on 4/4/09
Not much new to report about the eruption at Redoubt beyond the fact that it continues. AVO has kept the warning level at Red/Warning after briefly dropping it to Orange/Watch on Friday night. The 15,000 foot / 5 km-tall plume on Sunday was mostly water and volcanic gases. Eagle-eyed observers also noticed a plume on the lower flanks on the north side of the volcano that is believed to be steam generated by block & ash flows interacting with snow or water. These flow block & ash flows are coming…
eklemetti | April 4, 2009Today looks to be a doubleheader of volcano news:
RedoubtImage courtesy of AVO/USGS, taken by Rick Wessels. An infrared image of the north slope of Redoubt showing the hot, new dome material and hot block & ash flows confined to the valley.
At 11:30 AM yesterday, AVO put Redoubt back to Orange/Watch alert status after the volcano seem to settle down to small steam/ash plumes. Less than 12 hours later (at ~6:30 AM Alaska time), the volcano produced another large explosive eruption, sending an ash column up ~50,000 feet / 15 km and producing what seems to be a significant lahar that…
eklemetti | April 2, 2009
Image courtesy of Calvin Hall. Taken 3/28/2009 during an eruption at 10:59 AM3:28 PM.
UPDATE 4/2/2009 at 11 AM Pacific: I'm moving this up from the comments, but Eruptions reader Doug Cole pointed out (and I have no idea how I missed this) that Redoubt has a new webcam! This one is at the DFR seismic station, ~8 miles / 12 km northeast of the volcano. Great views on it today showing the extent of the ash around Redoubt and the steam/ash plume. This view will also be excellent if we get any dome collapse pyroclastic flows (see below).
After a week of explosions and ash fall, Redoubt seems to…
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 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 19, 2009Mixing volcanoes and oceans seem to always produce exciting results. Whether it is something as simple as the ocean entry of a lava to something as impressive as a new island emerging, formed by volcanic eruption. Back in the 1960s, a previous unknown undersea volcano off the coast of Iceland erupted to form the island of Surtsey. The signs of the impending eruption were captured from start to finish, with Icelandic fisherman noticing "boiling seas", then steam explosions, then ash eruptions and finally volcanic tephra that formed the island itself. This was followed by lava flows and…
eklemetti | March 17, 2009Image from keizo/weblog
Hunga Tonga-Hunga Ha'apai (how's that for a name?), a shallow seamount in Tonga, appears to have erupted. An air passenger snapped some pictures of an eruption occurring in the ocean between the Tongatapu and Vava'u and pilots in the area report that (unsurprisingly), the feature is new.
Hunga Tonga-Hunga Ha'apai - at least the part above water (look in the bottom of the image, the islands are marked in green) - is made of two small islands that cap the main seamount and ring the volcano's caldera. The last known eruption from the volcano was in 1988 - over twenty…
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 11, 2009The NASA Earth Observatory website posted this great image of Redoubt taken from Landsat images in 2000.
You can see a few neat things. The main thing I notice is that the Drift River Oil Terminal is in about the worst place you could put an oil terminal near a volcano like Redoubt. All the material from recent eruptions at Redoubt get focused down into the Drift River, which then heads off into the Cook Inlet via the Drift River flood plain (upper right hand side of the image). When this image was taken, the Drift River is still grey with volcanigenic material even 10 years after the last…
eklemetti | December 10, 2008
The latest eruption of Sourfriere was captured from space, and NASA has just released the MODIS picture of the volcano in action. The image (above and linked) was taken 2 days after the first explosion of this unanticipated and unexpected eruption - December 4. You definitely get the idea of how much of the island of Montserrat is taken up by the volcano itself (pretty much all of it). Not much else to report on Soufriere Hills beyond the update from MVO (via SI/USGS) for the end of last week:
On 3, 4, and 5 December small, relatively slow moving pyroclastic flows traveled no more than 3.2…
eklemetti | November 17, 2008
So, I get a steady diet of email messages here at the Eruptions HQ, so I thought I could try a little roundup of the great information/links that you readers are sending (and I apologize for taking so long for some of these). Enjoy!
- Tim Stone tells us about GeoEye pictures of volcanoes. GeoEye is the new satellite launched to add to the Google Earth images of the planet. There are some quite striking images of volcanoes included in the collection.
- Richard Roscoe sends us to some updated images of the on-going volcanic activity on Montserrat. As usual, there is an abundance of excellent…
eklemetti | November 17, 2008
Redoubt Volcano, in Alaska, is one of the more troublesome volcanoes in the state. Not only is it relatively close to population centers, but it also lies directly within the aircraft corridors above the Aleutians for planes headed to Asia and beyond. This means that USGS and AVO geologists have to be especially vigilant in watching Redoubt's every move.
Currently, the volcano has been recently changed to a yellow (elevated) alert, due to increased steam/volcanic gas emissions (remember, the number one volcanic gas is water vapor) at the volcano. So far, there haven't been any reported…
eklemetti | September 7, 2008
I wanted to post the new MODIS image of Chaiten that caught the volcano erupting on September 3. I won't go into too much details, there are a lot of great updates over on the Volcanism Blog, but needless to say, the volcano is still very active, producing tall ash columns (you can see the ash blanket around the volcano in the image above as the plume drifts off to the northwest), earthquakes and pyroclastic flows as the dome in the caldera continues to grow. I'll be interested to see what geologists know about the eruption and volcano when the AGU meeting rolls around in December as there…
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 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 | 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…