explosive eruption
eklemetti | May 15, 2008
To keep us up to date on the goings-on at Chaiten in southern Chile, well, the volcano is still erupting! Yes, two weeks in and heavy ash is still being erupted from vent. The latest reports are vague, but Chilean officials are saying things like "There's been additional volcanic activity that we're really worried about..." Now, I can only speculate what this means, but this might be an indicate that the SERNAGEOMIN are really beginning to seriously consider that the whole volcano may collapse.
The town of Chaiten, even without a collapse, is pretty much been wiped off the map. 90% of the…
eklemetti | May 14, 2008
A bit busy today, so to borrow from the newest USGS/SI Volcanism Report:
On 12 May, the plume rose to an altitude of 8 km (26,200 ft) a.s.l.
During an overflight conducted by SERNAGEOMIN, four more plumes of a
similar altitude were generated by explosions and drifted NE. Several
hectares of burned vegetation, likely from pyroclastic flows or
lateral explosions, were noted on the N flank of the dome. Small
pyroclastic flows may also have been responsible for completely burned
forest to areas in the NE, and on the W and NW dome flanks. A lahar
caused the banks of the Chaitén River to overflow…
eklemetti | May 13, 2008
I just read a report that the ash column at Chaiten is beginning to collapse. The SERNAGEOMIN says that the ash column is only 4.5 km tall now, as opposed to the 20 km it had reached earlier. Still, there are not reports of pyroclastic flows, but that could be a matter of hours or days at this point. We'll be keeping a close watch on the eruption to see if this is the beginning of the end, or just a lull in eruptive activity, here a full 12 days into the eruption.
UPDATE 12:20 PM (Pacific Time): According to this new article, the SERNAGEOMIN is reporting the first of the column-collapse…
eklemetti | May 12, 2008
Looks like we should expect an eruption at Ruapehu (New Zealand) any time now. Tremors are ongoing, along with increased volcanic gas emissions (specifically SO2 here) and warmer temperatures in Ruapehu's crater lake. All of these ingredients point to a higher probability of eruption.
However, with all that begin said, the Alert Level at Ruapehu remains at 1 (out of 5).
eklemetti | May 12, 2008Here is a gallery of some ridiculously cool photos from the Chaiten eruption ...
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eklemetti | May 12, 2008
I've been trying to keep up with the Chaiten eruption in Chile, but the news is just beginning to sound like a broken record: eruption continues, ash falls, don't know much else. However, it does sound like Chile is being realistic about people's chances of moving back to the town of Chaiten - 10 km from the vent(s) - in the near future ... and those chances are zero to none. This doesn't entirely surprise me. If the town isn't already buried, when the pyroclastic flows do start, whether they be from the collapse of the the eruptive column or from the vents themselves, the town will be…
eklemetti | May 10, 2008
Before we get too far, I wanted to make sure that folks understand that I'm just making educated conjectures on the nature of the eruptions I read about and by no means do I have any extra insight over those scientists on the ground at the eruption. I have a very limited set of data to examine - whatever the media reports - so I am just speculating based on what I know about the eruption style, volcano in question and whatever other variables might come into play. So, please, don't think that I know exactly what is going on or what will happen better than the scientists tackling the volcano…
eklemetti | May 9, 2008
This marks a full week of eruption at Chaiten and the volcano shows no signs of abating.
You have to feel for Luis Lara. He is apparently the pointman for the SERNAGEOMIN in regards to this eruption and really, I think its anybody's guess what might happen next. Heck, we haven't seen many eruptions of this scale - and this out-of-the-blue - since the birth of modern volcanology, so we're testing a lot of hypotheses now. What Dr. Lara says is that the eruption is still going strong, lava flows seem to be occurring at/near the vent but not spilling out of the caldera, the two vents have…
eklemetti | May 8, 2008
Another day, another development at Chaiten. Military stationed near the volcano helping with evacuations reported "booming noises" and saw incandescent blocks getting hurled from the vent area. This suggests that lava is at the surface and potentially that the edifice itself is beginning to crack/strain from the loss of material from the eruption. Remember, when you erupt all this volcanic material, you leave a void under the volcano where that magma used to be, so suddenly you have a volcano with no foundation. Sometimes they can founder into that space, forming a caldera. We already…
eklemetti | May 7, 2008
The eruption at Chaiten has now begun to have widescale effects on the region of Patagonia, beyond the ashfall. Air travel has been disrupted due to the amount of ash in the air. It is well-documented that ash posed a significant hazard to aircraft, so this seems like a wise move on the parts of Argentina and Chile.Â
Not much else new to report beyond that the fact that this eruption is now into day 6 without any signs of letting up. Impressive to say the least.
eklemetti | May 6, 2008NASA captured this great image of the ash plume from Chaiten, which has reached 15-km into the atmosphere.
Following this eruption, I'm sure there will be a lot of work into why no one had any clue an eruption of this magnitude was about to occur.
eklemetti | May 6, 2008
Well, this is getting rather harrowing. Volcan Chaiten, the Chilean volcano that sprung back to life last Friday after anywhere between 2,000 to 7,000 of quiet, is apparently erupting lava along with ash now. Sounds like its a good rhyolite/rhyodacite lava based on the description: "very small and very thick and as such was moving slowly so it is moving very slowly''.
Chilean officials are now fearing that the volcano is in "worst case scenario"Â mode - although, they never mention what that might be: full-on caldera? topography-erasing ignimbrite? Pinatubo-scale eruption? However, the…
eklemetti | May 5, 2008
For those of you who have missed it, Halemaumau Crater at Kilauea (Hawai'i, USA) have been experiencing new eruptions - some of them explosive - for the last couple months. These are the first eruptions at Halemaumau since the 1980s and the first explosive eruptions at Kilauea since the 1920s. Much of the area around the crater in Hawai'i Volcanoes National Park are closed due to the volcanic gases and the potential for more explosive eruptions to throw material out of the crater. These explosive eruptions are likely caused by the interaction between the magma below the surface intersecting…
eklemetti | May 5, 2008Monsters and Critics has some truly fabulous images of the ongoing eruption at Chaiten in Chile.
The pictures of the extent of ash fall are quite remarkable. It is hard to tell exactly how deep the ash is or how far from the vent these pictures were taken, but one can imagine that if a helicopter took them, then they are relatively far from the action. The Chilean President, Michelle Bachelet, toured the area to see the damage. Stunning stuff.
eklemetti | May 4, 2008
Update 5/4/08: Looks like there is now officially a deathtoll for Chaiten, as an elderly woman died during the evacuations. The volcanoes continues to spew ash and I wouldn't be surprised if it did so for at least a few more days. There have also been reports of a sharp increase in earthquakes in the area since the eruption. Now, before everyone goes nuts, this could be just a response to the dramatic release of pressure caused by the eruption, possibly faulting in the caldera walls activated by the eruption, or possibly magma working its way to the surface as the eruption progresses.…
eklemetti | May 3, 2008
Update 5/3/08: SERNAGEOMIN (the Chilean Geologic Survey) is now concerned that the eruption of Chaiten may be a the precursor of a larger eruption, mostly owing to the long (~9,000 year?) repose time. This could be the beginnings of a southern Andean Pinatubo.
The towns around Chaiten are more or less deserted now as the volcano continues to spew ash and pumice - upwards of 15 cm of ash in some places.
Edit: fixed link (thanks Mark)
Edit 2: fixed date of last eruption from ~7,000 years ago to ~9,000 years ago.
eklemetti | May 3, 2008
I've been following these rumblings for the last few months, but it looks like Colombia's Nevado del Huila is ramping into a new cycle of eruptions. Huila lives in the shadow of its more famous brethren Nevado del Ruiz and Galeras, both of which have had recent and tragic eruptions. Huila is not believed to have been active since the 1500s, but little research has been done on Huila (or any Colombian volcano beyond the aforementioned duo), so it might have had some fits and spasms in the last 500 years.Â
Reports from INGEOMINAS, the Colombian Geological Survey, say that Huila has been…
eklemetti | May 3, 2008
Ruapehu, in New Zealand, is starting to show signs it may erupt in the near future. It is a fairly active volcano, last erupting in Septemeber of 2007, but it is also a rather hazardous volcano thanks to the crater lake at the top that could be breached. Combined with the development on the volcano, it is a potent mix.
Now, why would you ever think to develop on an active volcano? Well, good question! There are ski areas on Ruapehu that are built on some of the lahar (volcanic mudflow) deposits on the side of the volcano and some of these lahars are not that old at all, so the likelihood…
eklemetti | May 3, 2008
So, this isn't exactly about current eruptions, but I was able to watch the new (well, to the U.S.) Doctor Who episode centered around the 79 A.D. eruption of Mt. Vesuvius. Now, to me, this was two of my favorite things (volcanoes and Doctor Who) fuses into one, and while I enjoyed it, it wasn't my favorite thing ever.
SPOILERS AHEAD!
The premise is that the Doctor and Donna accidently end up in Pompeii the day before the volcano erupts and buries the city in pyroclastic flows and ash fall. Of course, there is more than that going on. We find all sorts of nasty alien-related things going on…
eklemetti | May 2, 2008
The big eruption news today is an unexpected eruption in southern Chile. In fact, it is so unexpected that depending on when and where you read about it, you might get a different answer to what volcano is doing the eruption. What we do know at this point is an eruptive column has been spotted by people on the ground and the Washington VAAC, with estimates of an eruptive column height of between 35-55,000 feet. In other words: pretty darn sizeable. Ash is also coming down in town to the east of the eruption in Argentina. Now it seems that Chilean officials say Volcan Chaiten is the culprit…