Ash fall
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Not much news in the world of volcanoes this week so far. Must be the mid-summer lull in activity as the northern hemisphere heats up (just kidding!) Anyway, I thought I would post a picture of a recently erupting volcano that a friend of mine shared with me. This shot (above, picture by Arkadiy Groshev) was taken on July 25 of this year as Karymsky volcano in Kamchatka was erupting. The volcano emitted ash for ~1 hour that day and it almost seems like a volcano-as-tourist-attraction type of eruption! The group in the picture is the PIRE (Partnership for Volcanological Research and…
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 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:
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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…
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…
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…
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.
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…
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…
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.
Sorry 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…
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,…
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…
There are some astounding new pictures of Chaiten in full eruption over at the Smithsonian Website. There pictures were released by the USGS/VDAP team and show a full eruption column coming from the new dome in the Chaiten caldera (see above and below). The dome itself looks giant, filling up a lot of the old caldera (the highlands around the edge of the dome itself). The eruption is almost the antithesis of the 2004-08 Mt. Saint Helens dome eruptions which has produced a minute dome filling the 1980 crater. This rhyolite dome is the first major rhyolite eruption in almost 100 years, so I…
I found this picture on the SF Chronicle website and it speaks volumes about the destruction wreaked on Chaiten, Chile.
The ash has buried the town and what the ash hasn't damaged, the water and debris from the swelled river in the background have finished off. This is what volcanoes can do in the blink of an eye (geologically speaking).
Just when you thought it was safe to go outside.
After apparently settling down a bit over the weekend, Chaiten has kicked it back up a notch. The latest reports say that two ash columns are active ... and that is about all we get for more news. Not surprisingly, most of the damage around the volcano has been done by flooding and/or lahars, thanks to the ash and debris-choked rivers like Rio Blanco. It also sounds like the SERNAGEOMIN is digging in for the long-haul, calling for the eruption to go on - to some degree - for months. This isn't too shocking considering the minor dome eruption…