explosive eruption

I will be away from Eruptions for the next 2 weeks or so. I won't be on vacation, I will actually be out on volcanoes themselves doing some much-needed fieldwork. It is a three volcano tour, starting with a trip to Lassen Peak to get a guided view with Michael Clynne of the USGS (the world expert on the volcano, the last Cascade volcano to erupt other than Saint Helens). Then follows a trip to Mt. Hood with Adam Kent from Oregon State (my doctoral alma mater) in Oregon to sample some of the youngest flows that are only a few hundred years old. Geologists from Oregon DOGAMI (Department of…
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…
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…
I'll be brief (as I'm in the middle of moving), but I did see a report that activity at Chaiten is increasing yet again. This seems like the operating mode for this volcano, with a waxing and waning of intensity, since the volcano started erupting on May 2. The latest report indicates renewed ash emissions producing an ash column that reaches ~20,000 feet (4,000 meters), with ash falling on nearby areas. There is also mention of some increased seismic activity at the Chilean caldera. The picture above shows the extent of the mobilized ash and volcanic debris that has wiped out much of the…
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 AVO reported that seismicity remained low from August 10-12.
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…
Mayon, a volcano in the Philippines, is on watch for an eruption after experiencing small explosions. Philvolcs, (short for the Philippine Institute of Volcanology and Seismology), reports a small ash emission - ~200 feet - but they feel that there isn't an imminent threat of an eruption. Mayon is an relatively active volcano in the Philippines, last erupting in 2006 and is well known for its prototypical conical volcano shape (see above).
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:   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.
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…
The Okmok Caldera eruption is still going on, almost a month after it started. The latest USGS/SI Weekly Report states:    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…
So, August rolls in and who would have thought in early May we'd still be talking about the Chaiten eruption with such intensity. Jorge Munoz of the SERNAGEOMIN is wondering whether the current eruptive activity and seismicity at Chaiten is a precursor to the end of the "first cycle" (as he calls it) of activity that started in May or that this is all leading up to another major explosive eruption (the "plugged volcano" scenario). The most puzzling part of the current activity is the high amount of seismicity: 105 earthquakes over the last few days, some of them up to magnitude 4. The…
I'm always pleased to see more countries setting up volcanic monitoring networks. Well, I suppose I'm pleased when it is a volcanically-active country, I mean, Switzerland setting up one might be a little silly, but anyway. After last year's eruption of Jebel At Tair in the Red Sea, we were reminded that there are potentially active volcanoes in/near Arabian Peninsula countries like Yemen, so with the help of the Germany-Indonesian Tsunami Early Warning System, Yemen is setting up their own network to monitor volcanoes in the region. Little in the way of details were offered, but at least…
I have a few bits of news about one (of the three) volcanoes erupting in Ecuador. Reports from the Foreign and Commonwealth Office of Ecuador says the volcano is still erupting ash and there is evidence that lava is erupting from the summit vent. Not surprisingly, there is a travel ban on both Reventador and Tungurahua.
It seemed like events at Soufriere Hills had been heading for a dome collapse for the past few week and sure enough, part of the summit dome collapsed last night, producing pyroclastic flows that reached the ocean along with a 40,000 foot ash column. The report I received from the Montserrat Volcano Observatory offered the following details: The collapse started at 11:27 pm local time on Monday 28th July 2008 without any precursory activity. Part of the western side of the lava dome collapsed generating pyroclastic flows that reached Plymouth and the sea. There were also a few explosions…
Ecuador's Geophysical Institute is reporting that Reventador is currently erupting ash. Apparently, there is no threat to nearby Quito or any pipelines near the volcano. The volcano last erupted in 2007 (although the article incorrectly reports 2002) with small VEI 2 explosions and lava flows. The last major eruption was in 2002, a VEI 4 that spread ash over Quito and caused a number of fatalities. The 2002 eruption was an impressive one (see picture above), producing numerous lahars and a 17-km tall (~55,000 feet) ash column. This also makes two currently erupting volcanoes in Ecuador with…
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.
There haven't been any major developments volcano-wise over the weekend, just a few updates on some current rumblings:   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…
ONEMI, the Emergency Office of Chile, is expressing concerns that Chaiten might be readying an even bigger blast than what we've seen already in the past few months. In particular, ONEMI direction Carmen Fernández is concerned that the volcano might have a major explosion with accompanying ash fall and pyroclastic flows. They are pointing to the increased seismicity at depth under Chaiten as potential evidence that the conduit to the surface is partially blocked, and thus building pressure for a large explosion - think Augustus Gloop in Charlie and the Chocolate Factory if you want a…
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…
I am beginning to feel like a broken record, but the latest reports from Chile indicate that the ongoing eruption at Chaiten is ramping back up again, almost 3 months after the initial eruption began. As usual, the nitty-gritty details are limited, but reports of increased ash emissions and seismic activity are heralding this increase in activity. For certain, Chaiten is one of the most important eruptions in any of our lifetimes. This is really not because of the amount of material that has been erupted (although when all is said and done, it will be a significant volume), but rather for…