volcanic hazards
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, 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 8, 2008There are, indeed, other volcanoes erupting right now worldwide other than Chaiten. Of course, when you have an eruption like Chaiten going on, it is hard to pay attention to other eruptions.
Ubinas, Peru
Ubinas, in Peru, has been having intermittent ash eruptions for the past few months, depositing ash on the surround communities. Apparently these eruptions have been causing some respiratory ailments to the local Peruvians due to the ash & volcanic gases. Ubinas is one of the most active volcanoes in Peru. This picture shows Ubinas erupting in 2006, as captured from the International…
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, 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, 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…