Volcano monitoring in the news


So, there has been a lot of talk about “volcano monitoring” over the last 24 hours, now hasn’t there?
Now, I’m not going to revisit this discussion, but as an example of why it might be important, there is an article today about the location of the Bataan Nuclear Power Plant in the Philippines (near the potentially active caldera Natib). These are the sorts of issues that need to be dealt with in regards to volcano monitoring – the cascading effect of an eruption. During the 1980 eruption of Mt. Saint Helens, there was a chance that volcaniclastic sediment from the eruption could have dammed the Columbia River and cut off/limited cooling water to the Trojan Nuclear Power Plant nearby (see Beaulieu, J. D., and Peterson, N. V., 1981 pdf).
We all have different political views on how to help the U.S. economy. However, Stimulus Bill or not, it is irresponsible to put into the public consciousness that volcano monitoring is “wasteful” spending – and this is how it could be perceived. It is also been shown that monitoring volcanoes ends up saving much more money than it costs. I am sure there are plenty of other 0.01%s of the Bill that are much more wasteful but don’t add to the overall anti-science rhetoric in which this country is mired.
//Below are the comments for this article from the previous home of the blog.
Ed Kohut Says:
February 25, 2009 at 10:01 pm e
It is not just monitoring that is important. There is still much to learn about how volcanoes behave and there are potentially dangerous phenomena that have yet to observed in action and can only can be examined by studying the geologic record. Such studies do require some spending, but the cost is small relative to what the cost if something unexpected occured and thus no warning could be issued.
Tied into this is the fact that what a volcano did in the past is an indication of what it could do in the future. There are many volcanoes still awaiting detailed study and these could be potentially dangerous. Therefore basic field mapping and petrology are very important and need to be funded.
And while I’m on a soapbox taking up bandwith: it is not just politicians, but the academic departments that have declared subjects like volcanology, mineralogy and petrology are no long needed as core geologic disciplines. The refrain “nobody does that anymore” is heard from such places and simply adds to the problem of scientific ignorance when they grant “geology” degrees to people ignorant of these fields.
gg Says:
February 25, 2009 at 11:46 pm e
Isn’t this what has happened with Mount St. Helen’s? There is still a program in place, but funds are dwindling?
Here in Canada, we don’t bother with such things, even though we do have active volcanoes. Ignorance is bliss.
David Says:
February 26, 2009 at 3:57 pm e
i think Chaitén this had a big eruption i this here some in about it on TWC not sure
David Says:
February 26, 2009 at 4:04 pm e
SANTIAGO (Reuters) – Chile’s Chaiten volcano, which erupted spectacularly last year, spewed a vast cloud of ash as well as gas and molten rock on Thursday in a partial collapse of its cone, prompting a fresh evacuation.
Television footage showed a cloud of ash billowing into the sky over the town of Chaiten, which lies about six miles from the crater.
Authorities evacuated 160 people from the area. Around 7,000 nearby residents were evacuated last year after the volcano, dormant for thousands of years, erupted. The government is planning to relocate the town.
Officials from Chile’s national emergency office, Onemi, flew over the volcano and saw a kilometer-long crack in the cone of ash that has steadily grown in the crater, part of which has collapsed.
“Large quantities of gases and pyroclastic material were observed,” Onemi said in a statement, adding that rains in the area combined with the ash could cause flooding in and around the town of Chaiten, located 760 miles south of the capital Santiago.
However, while there was a large volume of ash, there had been none of the earth tremors or groaning sounds that accompanied the initial eruption last year, it said.
Interior Minister Edmundo Perez Yoma ordered all government personnel out of the area, and called on around 30 to 40 civilians who refuse to leave to follow suit.
“It is dangerous to stay in the area. They must leave,” Perez Yoma said. “We have insisted for a long time now that it is completely irresponsible to keep living in the town.”
“If they insist on staying there, they do so at their own risk,” he added. “We can’t keep risking public money or the lives of public workers to protect a few who don’t want to face reality.”
The government insists on moving the entire town. But some residents vow to stay put and are unfazed.
“I looked up and saw a tremendous column (of ash), just like in the beginning, one-and-a-half kilometers high,” Claudio Chelgui, a resident who decided to return to Chaiten despite government warnings, told local radio.
“I didn’t see much because it was overcast, and there was this huge column and fierce sound.”
Emergency officials are exasperated.
“We have repeatedly said there is a red alert and that people should not be there, and if that had been respected, then police would not be evacuating people,” an Onemi official said, asking not to be named.
He said the volcano has been in a permanent state of eruption since May of last year, when a cloud of debris soared as high as 20 miles into the air. The cloud was kept aloft for weeks by the pressure of constant eruptions, covering towns in neighboring Argentina with volcanic ash.
Chile’s chain of volcanoes, the second-largest in the world after Indonesia, includes some 2,000 — of which 500 are potentially active.
Erik Klemetti Says:
February 26, 2009 at 4:06 pm e
David – I’ll check on this, but that sounds suspiciously like an article I read last week when Chaiten erupted. Anybody else hear anything about more eruptions/collapses at Chaiten today?
Al Frank Says:
February 26, 2009 at 4:14 pm e
Not entirely on-topic, but there’s a video at the BBC showing what is presumably the latest eruption of Chaiten. Unfortunately, the accompanying article is quite uninformative.
http://news.bbc.co.uk/2/hi/americas/7912270.stm
Ron Hager Says:
February 26, 2009 at 4:42 pm e
Jindal is not a stupid man and probably is not really against scientific research. He is creating a certain image as a politician and thus can never admit that publicly. His comments were directed specifically at a constituency that is either anti science or hates anything Democratic. He wants to gain their support for a presidential run. Expect him to continue blasting away with his political rhetoric regardless of truth, accuracy or factual basis. He wants to leave a specific impression in the minds of that unique constituency, of which, sadly there are many. Many like me will reject him, but there are plenty of our fellow citizens that will delight in his attacks and become even more ardent in support of him.
volcanism Says:
February 26, 2009 at 5:15 pm e
Nothing new at Chaiten today, Erik – which is to say, the dome is still growing, steaming and fuming, blocks and ash roll down its slopes pretty much continuously, and small collapses and explosions occur every few hours. But no big collapses or upsurges in activity so far today. The Reuters report quoted above refers to the 19 February collapse.
(The big Chaiten story in the Chilean media today is the relocation of the town to Santa Barbara, which is a surprise as Bahia Pumalin was thought to be the favoured location.)
Gerhardus Says:
February 26, 2009 at 8:45 pm e
Sounds familiar …….it gets me very angry just thinking of it .. it leaves me without a way to express myself without being brutally rude or even disgustingly mean
Catch them and dump them on a volcano so that they can see the danger. Mother nature don’t care which brand of car or political grouping you like she’ll blow your a.. off without even feeling sad about it
Just because I’m a Republican with political agenda gives me the right to endanger thousand or even millions of other people.
lance jones Says:
February 27, 2009 at 1:41 pm e
Well, I am a Republican with a political agenda. I think you guys are missing the point. I think volcano monitoring is something we need to do, probably a lot more. (My undergraduate degree is in geology). The question is whether or not it is “economic stimulus.” Volcano monitoring is not. The person to be mad at is the person who added it to the stimulus bill. There are a million things that more money needs to be budgeted for. This should have been in the regular budget, not this emergency package. We are borrowing this money from our children. If we need more geological monitoring of volcanoes, earthquakes, etc. (and we do) it should go through the normal budget process.
eileen Says:
February 27, 2009 at 9:33 pm e
Lance, what I remember about Jindal’s speech is that he called volcano monitoring “wasteful spending.” He wasn’t implying that it didn’t belong in the stimulus bill, he was stating that we shouldn’t be spending money on it at all. Volcano monitoring, by the way, is stimulus. The folks at Trimble (who recently laid off workers) would be happy to sell the USGS more GPS instruments, for example. How is buying goods and services not stimulus?
lancejones Says:
March 3, 2009 at 9:40 pm e
Eileen, from the CNN report
“The governor, a rising Republican star, questioned why “something called ‘volcano monitoring’ ” was included in the nearly $800 billion economic stimulus bill Obama signed earlier this month.”
All spending is “economic stimulus” in the broadest sense.
Anyway, it is better spent on any scientific research than poured down the AIG/Citi/GM/
Chrysler hole.

Redoubt Mini-update for 2/24/2009

Not much new to report with Redoubt except that folks in Alaska are getting, well, a little punchy.
AVO currently reports (7:12 AM):

Volcanic tremor and occasional discrete earthquakes continue at Redoubt. Since 00:00 local time on 2/24, tremor amplitude at nearby stations has gradually increased, and the number of small earthquakes on nearby stations has increased slightly.

Redoubt isn’t exactly making us volcanologists look too good lately. That is the nature of the beast, I suppose.

Volcanism and society: What to do about Chaiten


I have never had to leave my home in an evacuation from a natural disaster. I’ll put that out there right now. So, I might not fully understand the emotions going through people when they find out that they have to leave their home by no fault of their own because nature has decided that where they live is no longer livable. I especially don’t know what it might be like if you are then told you can never go back. You might have a home there. You might own a business there. You might have grown up there. Your great grandparents might have lived there over 100 years ago. Yet, you are told – likely by the government – you can never go back because they have deemed it “unsafe”. I’m not even sure who I would respond, especially if you are able to go back to your home to collect your belongings and you see that the town is still there – its not like it has been wiped off the face of the earth. Why should you leave? Isn’t it your decision about where you live (and die)?
This is the struggle going on right now in Chaiten, Chile. The volcano has been erupting since May of 2008 with one of the most spectacular eruptions in the (modern) history of Chile, with its latest outburst coming last Thursday (2/19), producing impressive pyroclastic flows and ash falls that blanketed the countryside around the rhyolite volcano and destroyed more of the town of Chaiten (above). Yet even after all this and even after the government has announced that Chaiten (the town) will not be rebuilt, people will not leave. The Chilean government has told the last 200 residents of Chaiten that they must be evacuated from the town, especially after the powerful (and unexpected) outburst from the volcano only 10 kilometers from the town, but a few dozen people have decided they will not leave. I don’t want to judge these people, but living near an active, explosive volcano is dangerous and when destruction comes, you likely won’t have any warning (or at least not enough time to do anything about it). You can’t really mitigate against a pyroclastic flow like you can against flooding or earthquake hazards – a town in the path of a pyroclastic flow will not survive – so you can’t blame the government for wanting to just declare Chaiten a “lost town” and move the residents to a safer area. However, the people refusing to leave don’t see it that way, and the matter is heading into the Chilean courts and even into the Presidential election in Chile.
This is a difficult situation. The last Chaiteninos say the government didn’t give them a say in the decision to abandon the town. However, there really isn’t much to discuss with the townspeople – you stay, and likely Chaiten will destroy you or your home. You leave, you leave behind the town you called home and everything in which you are familiar. There is no easy solution. What would you do in this situation? Have any of you face this type of thing? This is really where man and nature butt heads and most of the time, nature wins.
//Below are the comments left on my original blog concerning this post – it was an excellent discussion//
Brian Owens Says:
February 23, 2009 at 7:27 pm e
Sometimes it is easy for us in modern society with the best scientists to look down on people like that, and say they are superstitious and ignorant. But I clearly remember the same thing happened with Mt. St. Helens in 1980. There were a lot of angry home owners and property owners that were upset because they had been evacuated from the Red Zone. Some of them were saying the scientists had no idea what they were talking about, that it would not have a big eruption, etc.
In fact, the day before the big eruption, the authorities escorted groups of them during the day to check on their property. Had it erupted that day instead, a lot more people would have died.
I think it is human nature to be in denial. Smokers don’t think they will get lung cancer, despite all the warning. Some people still do not wear their seat belts. And many of us know about the struggle with weight (including me, I have lost a lot of weight, but it is still hard to maintain), despite that we all know the consequences.
Human nature I think is to think that “it won’t happen to me”. Certainly in some cultures there is ignorance of science, but I think it is more human nature.
And one of the problems is that scientists don’t really know what it will do. Will there be an end-game huge eruption? Will there be devastating pyroclastic flows? Nobody can say with certainty, and unfortunately, that is what people want.
lance Says:
February 23, 2009 at 7:40 pm e
My libertarian bones say let them stay. If they are killed, it is the choice they made. But, in another emergency people will go try to rescue them, putting others in danger. It is like the people along the Mississippi who insist on rebuilding their houses in flood zones. No matter how tough you are about saying you are going to refuse help, when the time comes, you know that they will be rescued and sent help in the next flood.
Humans and hazards « Volcanista: a magmalicious blog Says:
February 23, 2009 at 8:22 pm e
[…] Geoblogosphere! Science seminar video February 23, 2009Volcanism and society: What to do about Chaiten February 23, 2009WaterWatch — Current Water Resources Conditions (USGS) February 23, 2009The […]
Ron de Haan Says:
February 23, 2009 at 8:29 pm e
History provides insight in what happened o cities after a devastating volcanic eruption, a flood or an earthquake.
Most of them have been rebuild.
Just look at Mount Vesuvius in Italy.
Despite the threat of a new eruption people people have stayed and populations have grown.
The same will happen to the town of Chaitén.
jesse Says:
February 23, 2009 at 9:12 pm e
I think there’s 2 issues at play here. First, we here in modern society see moving as a much easier task than many people. Want to move to rural Kansas? Call a mover, find an apartment, and go. But my guess is, in places like Chaiten the people don’t have the same resources as us, and moving to a completely new, unknown, foreign place is a lot more daunting. I imagine it’d be a lot like someone saying “OK Erik. Tomorrow you’re moving to Istambul. You can only take what you can carry on your back, and you can’t buy any new bags or suitcases. Ready? GO!”
Secondly, pepole are inherantly stubborn. When Hurricane Ike was bearing down on us here in the Gulf, there were dozens if not hundreds of people who wouldn’t leave Galveston island, even though you could literally see the storm approaching out your window. What did the govt say? “Write your SSN# on your arm with a sharpie so we can identify your body. You will face certain death.” Did people leave? Nope (well, hopefully a few more did). It’s that pesky “invincible” gene people have.
Bruce Says:
February 23, 2009 at 11:26 pm e
Nicely written piece and sums it up quite nicely. While I respect people’s freedom to take risks with their own lives I think society should draw the line when others’ lives are at risk. This is certainly the case when children are involved..
As an individual I could imagine taking such risks but I think the authorities (and volcanologists who inform the authorities) are in a totally different position. They have a duty to save life first and foremost.
The real trouble is not so much in this principle but in where to set the border? How likely is it that a PF will reach Chaiten town? It appears that this chance is very likely, ( but then again so is the chance of a major earthquake in SoCal.)
If I had grown up in Chaiten I’d have moved out by now and would be waiting until the volcano quietened down before moving back. I think the authorities are doing the right thing.
volcanism Says:
February 24, 2009 at 9:10 am e
A good article that takes a humane and balanced, but also a realistic, view. Thanks, Erik.
An interesting point for me is that opinion in the rest of Chile does not seem to be particularly sympathetic to the Chaiten diehards (who are, it’s important to note, a tiny minority of those who have been evacuated). Chileans elsewhere in the country see the chaiteninos being offered a very good deal with support and guarantees they themselves could never hope to receive. They have also seen protesting chaiteninos waving Argentine flags and claiming that Argentina has their interests at heart more than their own country. That gesture went down very badly in Chile. National policitians who try to exploit Chaiten in the approaching elections are unlikely to find it will do them any good.
You have to feel human sympathy with the people of Chaiten, but their case is a hopeless one. They have not been well served, by the national Government which has taken ages over making its final decision over their future and has sent out ambiguous signals, and by local politicians who have grandstanded over the issue and irresponsibly raised hopes in the people of Chaiten that could never be fulfilled.
In the end it isn’t the Chilean Government’s job to sustain a self-indulgent few in their delusions, particularly when doing so means putting the lives of others on the line.
boris behncke Says:
February 24, 2009 at 11:56 am e
This is a very sensibly written essay on a very pressing problem in modern volcanology, which in this particular case concerns a relatively small number of persons, but in other cases may involve considerably larger numbers of people. Basically, volcanologists and collaborating administrations and civil defence staff are in the grip of two main uncertainties, one is how the volcano will behave, and the other is how the affected people will behave. It is known from many cases that during volcanic crises there have always been a certain number of people reluctant or right away refusing to leave areas defined as dangerous. Let’s remember, to name a few, Harry Truman and others – as mentioned above in the first comment – at Mount St. Helens in 1980, or the people who died in 1997 at Soufrière Hills on Montserrat, all in areas clearly described as highly dangerous and basically off-limits by previous warnings given by volcanologists. Such behavior is like driving dangerously (something I experience everyday in Catania, Sicily) while well knowing that this can endanger your and other people’s lives. Or whatever sort of drug use (including excessive smoking and alcohol consumption), you know about the risk but you do it nonetheless. In the case of people facing evacuation there is an additional factor, there is a lot to lose. I certainly find it an absolute horror vision to imagine that one day I might be forced to leave my home (what with the entire volcanology stuff that I call my own, including hundreds of books and papers …) because Etna decides to open a new vent nearby. Certainly I would move away because I know the risk, but it would be one extreme hardship. Now imagine you do not really know about the risk and you are really not convinced.
And then, volcanoes do not only do what volcanologists believe they will do. Redoubt is a fine example, for the moment. Anyone remember the Soufrière of Guadeloupe (Caribbean) crisis in 1976-1977? At that time more than 70,000 people were evacuated because a pyroclastic-flow-generating eruption was considered imminent by some scientists, although others said there would be no major eruption. Eventually an international team of volcanologists stated that there was indeed no risk of a major eruption, and evacuees were allowed to return home – after three months of living under unimaginable conditions.
Now let’s imagine next time it will be Vesuvius in Italy to give signs of life. An emergency plan elaborated by Civil Defence, authorities and volcanologists envisages evacuation of more than half a million people from the areas of highest risk. Let us now imagine this evacuation is performed smoothly (difficult to imagine, frankly, for anyone knowing the reality of traffic, lifelines, and organization in that area), and all those people are brought away (although we would certainly experience the same cases of people strictly refusing to leave). And Vesuvius does the same thing as Redoubt in these days – it trembles, it fumes, but it does not erupt, for one week, two weeks, one month … for how long? For how long will it be economically and humanely bearable to keep more than half a million people from their normal social, cultural and economic life?
The simultaneous developments at Chaitén and Redoubt are very strong reminders of how far we will still have to go to come to a complete understanding of the volcanic and anthropological factors interacting in volcanic crises, and how likely it is that we will continue to be taught painful lessons.
Under the volcano, Chaitén diehards continue their fight « The Volcanism Blog Says:
February 24, 2009 at 1:42 pm e
[…] At the Eruptions blog, Erik Klemetti has written a well-balanced piece on the Chaitén situation, with more general reference to the difficulties of persuading people to abandon their homes and the lives they have known in the face of volcanic hazards, actual or predicted: ‘Volcanism and society: What to do about Chaiten’. […]
gg Says:
February 24, 2009 at 2:09 pm e
Remember Harry Truman of Mount St. Helen’s? He died on that peak.
Melissa Says:
February 24, 2009 at 7:47 pm e
The people of Chaiten are a wonderful people, and although they are Chilenos, they are even more so very cultured and very good people. I have had the benefit of living in Chaiten in February 2008, months before the first eruption, and it’s a very unique town. It was the center for tourism in southern Chile, a gateway to patagonia. A gateway to the entrance of the southern edge of Parque Pumalin (the many million hectar reserve by the founder of Patagonia company…which is amazing). It was a gateway to the other nearby town of Futalefu, for all the white water die hards who traveled by sea vs thru Argentina by land.
I have a hard time watching all this happen to Chaiten, and wonder about the families I have known and the people I dined with, danced with, drank with, played music with, walked with and talked with. There is and there will be no other similar place in Chile. I think it is wonderful that these people want to stay in their homes, and to be honest with you I can’t blame them. I feel that they must have hope that the volcano will eventually rest and they will be able to rebuild the town to the seaport town that it once was. In fact, I dream of the day that I can buy property in the area, as I would like to retire there, and no volcano is going to stop me either. I know the risks, but to live in an area with true beauty is worth those risks, and know that with the Chaiteninos, I’ll die happy.
Breier Ralf Says:
February 24, 2009 at 8:45 pm e
I am working on a documentary about Chaiten for German public television. I have been to Chaiten several times since April 2007. I have been filming a lot of material before the volcano erupted and after. We intend to do a long documentary of 90 minutes and will follow up the development of the tragedy and the people who lost their homeland.
werner luis Says:
February 25, 2009 at 1:38 am e
I am living now 60 year near volcanoes and I agree with Ron de Haan and Melissa. Chaiten will continue with or without the help of government.
J Says:
February 25, 2009 at 3:33 pm e
Chaiteninos are responding in a pretty reasonable manner to an impossible situation. I have been following this eruption since last year when it began and with the volcano’s initial decline it would be easy to sense that the major danger is over, even with the recent unrest. And who could blame them for treating their government with skepticism. The government has not acted in their best interest so far.
If I could elaborate a bit more on Erik’s comment “I especially don’t know what it might be like if you are then told you can never go back. You might have a home there. You might own a business there. You might have grown up there. Your great grandparents might have lived there over 100 years ago. Yet, you are told – likely by the government – you can never go back because they have deemed it “unsafe”.”
I don’t know from personal experience either but I imagine the consequences are more intricate than I can even imagine, and here is what I can imagine…
Home – not just purchased by you but likely built by you and your family and your friends.
Business – Chaiteninos developed their town into a bit of a tourist destination. If you have ever considered taking the chance on a career change. Doing something completely different than you have ever done before professionally, you can appreciate the courage, and dedication it must have taken for the citizens to embrace that kind of change.
Family has lived there over 100 years – That is 100 years worth of family buried beneath the volcano, including parents, sisters, brothers, husbands, wives and children.
Bruce S. Says:
February 25, 2009 at 10:25 pm e
An Ralf Breier: wann wird es ausgestrahlt? Das muss ich unbedingt sehen!!
Chance Metz Says:
February 26, 2009 at 2:09 am e
To J I have this to say.Don’t you get that it is not safe there? This volcano is still erutping and the lava dome could collapse at anytime. the town is finsished,done and there is nothing that can change thta. You can’t grow anytihng there due to the ash you have no water electricity,heat,telphone or sewage so how can you live there? Tell me that one? Really if you side with them then go there and be one f the people that will die there like they are sure t do if they stay!
Breier Ralf Says:
February 26, 2009 at 7:40 pm e
Message for Bruce S. : I don´t know when we will be ready with our long documentary. We might finish when decisions on both sides fall into places. I am on my way to Chile and will be back by end of March with new material. The ministro del Interior made a decision for the Nuevo Chaitén just today. Some people will start rebuilding the Nuevo Chaitén pretty soon and some will stay on their own in the old town Chaitén.
Will keep you posted or just check our website, we will announce the dates for broadcasting. The 30 minute reportage will be broadcasted by WDR – German public television on March 24th at 10:00 p.m. German time.
yellow bird Says:
February 27, 2009 at 5:41 am e
I can not understand peoples attachment to buildings. They are just bricks & mortar but I do not evacuate without my pets & the native animals who visit my garden & I would kill anyone who would stop me from doing this. However if all the native animals are dead what is the point of staying? I think Chaiten is dead & it should never be rebuilt. lt should become part of the national park there. Let the native vegetation regrow & the ruins can be a tourist attraction.
Entriqued Says:
March 4, 2009 at 5:37 pm e
I don’t know, that looks livable to me. I’ll take the green roof right on the edge. Great river view!! Spacious living.
Sure why not!
When the river is eye level I’ll just go upstairs.

Redoubt Mini-update for 2/23/2009

Nothing much to report on the Redoubt front except more of the same. The latest report from AVO says (6:44 AM):

Redoubt Volcano has not erupted. Volcanic tremor and intermittent discrete earthquakes continue. Data for the past few hours (since 00:00 AST on 2/23) has consisted almost entirely of low-level tremor, with few discrete earthquakes.

So, it seems that Redoubt continues on its holding pattern. In other fronts, the Anchorage Daily News is running a good synopsis of the monitoring AVO does on volcanoes in the Aleutian chain in Alaska. More updates as seen fit.

A third ocean lava entry at Kilauea


Lava issuing from the current eruptions at Kilauea have started a third ocean entry (and the second within the Hawai’i Volcanoes National Park). The entry is not as dramatic as some, forming a slow, dripping entry of lava into the ocean (see linked video footage), but every little drip adds a little more land to the big island of Hawai’i.
In some other Hawaiian volcano news, the USGS have also posted a video showing the filling and draining of the lava lake in Halemaumau that started last year. Usually, the crater was surrounded by steam and fumes from the degassing magma, but the thermal camera pierced the veil to show the lava rising and falling within the crater.

More activity at Galeras


Galeras, in Colombia, appears to have entered a new cycle of activity as it has erupted for the second time in a week. A large explosion occurred this morning that was accompanied by falling ash and rocks (ballistic bombs) from the event. It is unclear how far the volcanic products travelled from the vent, but Colombian officials did raise the alert level back to red and ordered new evacuations.

A review of ash cloud classification

Jonathan Castro has reminded me that I need a refresher on the proper terminology for ash columns related to volcanic eruptions. It is very easy to start mincing words and using them inappropriately – and that is the sort of sloppy reporting and discussion I am trying to avoid.

So, to refresh my (and our) memory on ash clouds and how to classify them, we can go back to one of the indispensable textbooks on volcanology, Cas and Wright’s Volcanic Successions. The classification scheme they provide is summarized in the figure above. It shows the heights of various eruption columns and the relationship between types of eruptions and their “explosiveness”. Jonathan is likely correct in classifying this eruption in the vulcanian range (<20 km ash column), especially if it was driven by explosions in the dome. If anything, Chaiten’s activity today could be sub-plinian, but a true plinian eruption requires a taller ash column height and higher levels of explosivity.
UPDATE 2/20/2009: Here is a link to an article that talks about the processes that go along with each eruptive style. Remember, the ash column nomenclature is not solely dependent on height, but also process and composition. {Thanks to Boris for reminding me to emphasize this.}

Chaiten Redux


UPDATE 2/19/2009 9:45 AM: Well, it seems that my hunch was at least partially right. Reuters (and Paula Narvaez, special envoy to the Chilean president) is calling the eruption as result of “what appeared to be a partial collapse of its cone.” So, we might have seen the oversteepening of the dome growing in the Chaiten caldera that lead to a collapse, producing (likely) a pyroclastic flow and either an accompanying plinian eruption as the pressure was released or an ash column associated with the pyroclastic flow itself. Now, I might not take Reuters word for it, but it makes sense considering the suddenness of the event.
10:00 AM: More details for Reuters, including the ominous “Our security team have observed an increase in the size of a column of ash and smoke, with a deformation to one side” from the Deputy Interior Minister. My guess is he is referring to deformation on the ash column, not the volcano.
4:00 PM: From a Newsday article, just some more details on the ash dispersal: “On Thursday, increased seismic activity was reported and ash fell 100 miles (160 kilometers) away in Futaleufu.”

Eruptions reader Brian Owens has pointed out that fellow volcano follower, the Volcanism Blog, is reporting that Chaiten is experience a major rejuvenation today.
Sure enough, the Associated Press also reporting that an explosion has occurred in the main dome of Chaiten that has been built since last May and that material is moving downslope from the explosion. There is no clear word what type of volcanigenic material this might be – pyroclastic flow, lahars, avalanche – but there is a major fear that it could block the river and cause flooding in the town of Chaiten. The few citizens left in the area are being evacuated. The Patagonia Times adds that the eruption started around 11 A.M. (local time) and ash has spread across much of the region.
From what I can gather, this seems like it might have been either a dome collapse that was quickly followed by an explosion (possibly caused by the release of pressure from the collapse) or some “burp” of gas-rich magma erupting. The reports of “a massive column of ash” are interesting as this could suggest a true new flux of magma, but it is hard to tell at this point how widespread is the ash and how tall the column might be. At this point, it is all conjecture, but it sounds like Chaiten might be making a comeback. The questions woulds be how big and for how long.
I’ll update as we find out more …

Japan planning ahead … way ahead


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 will watch seismicity for signs of activity, or will this be a dedicated position that coordinates seismic, gas and deformation monitoring? The article doesn’t say much beyond seismographs and (vaguely) GPS. Nor does it mention what the seven new volcanoes are beyond Mt. Shirane and Mt. Norikura. However, I do give Japan credit for having such foresight when it comes to potential volcanic hazards.
One volcano that is already being constantly monitored is Mt. Asama, which has been erupting for over week. However, folks are already wondering when officials will say that Asama is “back to normal”. You can get a good idea of the ash dispersal from Asama with this excellent satellite image (above) from just after the January 21, 2009 eruption.