volcanic hazards
eklemetti | July 31, 2008
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…
eklemetti | July 30, 2008
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.
eklemetti | July 29, 2008
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…
eklemetti | July 28, 2008
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…
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
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…
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 24, 2008
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…
eklemetti | July 22, 2008
Admittedly, this is only a brief report, but there are indications that Tungurahua in Ecuador might be heading into a new period of heightened activity. Over the last week or so, there has been increased seismicity, reports of "booming noises" and increased ash emissions from the volcano. Being one of the more active volcanoes in the Andes, it would be surprising if the new eruptions were very big, but instead we might expect more frequent moderate ash and pyroclastic eruptions. However, with this little information, it is hard to tell what might happen and I'll keep my eyes peeled for more…
eklemetti | July 22, 2008
There were a number of small explosive events at Soufriere Hills in Montserrat in the past few days. Small ash columns of ~5,000 feet were produced, likely caused by some degassing or interaction with water of the andesite dome at the top of the volcano. The director of the Montserrat Volcano Observatory says there is little concern for heightened activity. The volcano has been erupting off-and-on since 1995 and these eruptions are just part of the ebb-and-flow of this period of activity.
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 21, 2008
The latest eruption at Llaima is beginning to slow down according to Chilean state geologist, Hugo Moreno. The volcano has been erupting for most of the month, forcing limited evacuations. The eruption has (so far) produced lava flows, ash falls and some bombs thrown from the crater. However, the SERNAGEOMIN is keeping the "red alert" on Llaima.
With persistently active volcanoes like Llaima, it is not surprising that they see multiple eruptive periods during each year. In a sense, this is actually better for the people living around the volcano because the more often the volcano erupts, the…
eklemetti | July 21, 2008
I suppose this is more "unnews" than "news", but workers at Ruapehu in New Zealand report that seismicity has decreased, gas emissions have returned to background and the crater lake has cooled, indicating that the current eruptive cycle which started in September 2007 might be winding down. There was some concern earlier in the summer (well, northern hemisphere summer) that it was cranking up to erupt, but these fears seem to have abated. As always, though, Ruapehu remains on "elevated alert" for eruption.
eklemetti | July 20, 2008
It has been a while since we've seen a Chaiten update, but today there is a report that LanChile has had to cancel flights to Puerto Montt due to ash from the volcano. Chaiten has been erupting since early May, so now we're almost 2 1/2 months into the eruption - quite a feat for such a large eruption! The report also mentions that some residents of the town of Chaiten have been able to visit their homes to collect belonging and the government might just try to rebuild the town in an entirely new location. The USGS plans to send geologists to the volcano later in 2008 or early 2009 to survey…
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, 2008
Not really a "new eruption" as such, but the Geophysics Institute of Ecuador is reporting that Tungurahua, one of the most active volcanoes in South America, has been erupting ash and bombs as of late, along with showing signs of increased seismicity. Nothing new for this tongue-twister of a volcano as it has been erupting since 1999.
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,…