volcanic hazards
eklemetti | January 20, 2009
Nevado del Huila continues to cause problems in Colombia. Over 4,000 people had to be evacuated today from the Belalcazar area after the volcano showed new signs of eruption. No description is given to exactly what those signs were/are, however after the lahars in November (2008), it sounds like the Colombian government is not taking chances. Huila has been rumbling for almost two years now after almost 450 years on silence (that we know of) at the volcano.
eklemetti | January 19, 2009
One of the more impressive areas I visited while in New Zealand was the Waimangu Valley near Mt. Tarawera (above). The valley itself was created by blast explosions (phreatic explosions) during the 1886 eruption of Mt. Tarawera. These eruptions cut right down the axis of the rhyolite domes (most of which erupted ~1305 A.D.) and extended off the volcanic edifice to form the valley to the west of the volcano. In the valley, no juvenile lava was erupted, instead explosions carved out large pits that formed the Waimangu Valley and today the valley is filled with lakes and thermal features (below…
eklemetti | January 1, 2009
I just wanted to point folks to an interview in US News & World Report with the USGS scientist-in-charge of the Yellowstone Volcano Observatory, Dr. Jacob Lowenstern. He plays down the swarm, noting that things like this happened in the 1980s and that Yellowstone has seen over 80 eruptions in the caldera since the last "supervolcano" eruption 640,000 years ago. I know Dr. Lowenstern pretty well, and even at AGU when I talked to him (before the swarm), he seemed to play down the huffing and puffing the caldera experiences on a yearly basis. It would take much more activity to get the YVO…
eklemetti | December 31, 2008
Yellowstone looks to be keeping everyone on their toes as we ring in 2009. The earthquake swarm reported earlier this week is continuing, with multiple events between 2-3.5 on the Richter Scale. Again, the folks monitoring the caldera - this time the Univ. of Utah - play down these events as normal for any active caldera system ... and they're very likely right. However, the media love to bring up the "supervolcano" angle and we're even getting expert opinion from (wait for it) Garrison Keillor!. Â The earthquakes are just normal earthquakes so far - none of the dreaded/anticipated harmonic…
eklemetti | December 29, 2008
Some more information is coming out about the activity at Koryak (aka Koryaksky) in Kamchatka. Russian geologist Alexei Ozerov says that the activity at Koryak (note: the image in the article linked here appears to have nothing to do with Koryak) has started with more power than the last known eruption of the volcano in 1956. He also mentions that the volcano is already a danger to aviation in the area (as the closing of the Petropavlosvk-Kamchatsky Airport suggested).
We also have some great images of the volcano, showing the vent on the side of the volcano (see above). It is hard to tell…
eklemetti | December 29, 2008
2008 is almost finished and we've seen one of the few high-silica rhyolite eruptions in the past 100 years at Chaiten in Chile. Chaiten was definitely not high on the list of potential locations for a rhyolite eruption worldwide. However, Yellowstone Caldera in Wyoming definitely is high of the list because it has erupted a lot of rhyolite over the last few 100,000 years (even discounting the big so-called "supervolcano" eruptions).
This is why the current news of an earthquake swarm at Yellowstone is, in the very least, really interesting. The earthquakes - over 250 of them - started…
eklemetti | December 28, 2008
News is filtering in that Koryak (aka Koryaksky) Volcano in Kamchatka might be heading towards an explosive eruption. The details are scarce, but it seems that a breach on the northwest slopes of the volcano might cause an explosive eruption, however, it is not clear why this is. All this talk has caused the Petropavlosvk-Kamchatsky Airport (~13 miles northeast) to close in fears of this potential activity.
Koryak is yet another potentially active volcano on the Kamchatka Peninsula, along with currently active Bezymianny, Kliuchevskoi, Karymsky and Shiveluch. The last eruption at Koryak…
eklemetti | December 11, 2008
When people think about volcanic mitigation, a lot of time is spent worrying about monitoring and science. There is nothing wrong with this as we need to know what the volcano has done in the past and what it is doing now to predict its future activity. However, a very important piece of the mitigation puzzle is education, because without educating the public of the dangers of the volcano, many times they will not listen to officials when time for evacuation comes (see Nevado del Ruiz, Colombia in 1985). That is why this report from Tanzania is great: scientists going out and educating the…
eklemetti | December 11, 2008
Sometimes I wonder if we know more about the fates of people who died in a volcanic eruption over 1800 years ago than we do about most people who died in any given eruption this year. Not that there is anything particularly wrong with that - we're fascinated by both volcanoes and Roman antiquity - but the level of detail done for the victims of Vesuvius in 79 A.D. is stunning.
Considering that this blog got started (to an extent) thanks to our cultural obsession with Pompeii, I thought it fitting to post a bit about a recent report on the last moments of a family in Pompeii. Nothing really…
eklemetti | December 10, 2008
The latest eruption of Sourfriere was captured from space, and NASA has just released the MODIS picture of the volcano in action. The image (above and linked) was taken 2 days after the first explosion of this unanticipated and unexpected eruption - December 4. You definitely get the idea of how much of the island of Montserrat is taken up by the volcano itself (pretty much all of it). Not much else to report on Soufriere Hills beyond the update from MVO (via SI/USGS) for the end of last week:
On 3, 4, and 5 December small, relatively slow moving pyroclastic flows traveled no more than 3.2…
eklemetti | December 5, 2008
The blasts and pyroclastic flow from earlier this week at Soufriere Hills in Montserrat were not the only show planned for the week, apparently. The volcano continues to erupt, with reports of continued ash and ballistic glowing bombs being erupted. These eruptions are the first major ones at Soufriere Hills in 6 months, but are apparently unique with no real precursors such as seismicity (well, none identified as of yet).
eklemetti | December 4, 2008
Although this news isn't as threatening as the title of the article implies:Â HAWAII LAVA FLOW NEARS NATIONAL PARK, it is still some news as it could be the first lava flow to cross into the park in over a lava. The flow itself is headed towards what is called the "Waikupanaha ocean entry" on the southeast side of the island. The lava flow has about one mile to go before it reaches the Pacific Ocean, but it has travelled several hundred feet (maybe 100 meters) over the last 10 days according to Park Rangers and USGS geologists monitoring the flow's progress.
Of course, compared to your…
eklemetti | December 3, 2008
Just to keep everyone on their toes, Soufriere Hills on Montserrat in the West Indies erupted today. The eruption produced a number of explosions and a pyroclastic flow that originated from the west side of the lava dome at the summit of the volcano. However, the most interesting bit comes from the Montserrat Volcano Observatory (MVO) report I received this morning:
"The explosion happened without any warning. There was no precursory seismic activity."
Sounds like it could have been a dome collapse caused by a rapid release of gas/steam? The explosion apparently threw blocks as far as a…
eklemetti | December 1, 2008
A quick update from Reunion Island on this fairly slow week, volcanically speaking:
"After permanent unrest with daily 30 to 100 seismic events, Piton de
la Fournaise volcano erupted again on Thursday November 27, 2008 at
11h50. The eruption is situated on the west side within the Dolomieu
crater at the same vent as the September 21 eruption and can probably
be considered as a second phase of the later."
This comes from the Observatoire Volcanologique du Piton de la Fournaise (OVPF - link in French). Piton de la Fournaise is a shield volcano on Reunion Island that sees frequent basaltic…
eklemetti | November 24, 2008
The lahars and mudslides near Nevado del Huila - or, in particular, the threat of more - have prompted more evacuations. Although the known death toll from the eruption and its associated lahars is still officially only in the low double digits, at least 150 people are still missing, so that may change. You can see in the photo from Belalcazar (above) that the mud inundated the town and destroyed roads and buildings easily. This is what to expect whenever lahars are generated, along with the potential for flooding afterwards due to the dewatering of the mudflows and the blockage of drainage…
eklemetti | November 23, 2008
I've found a few more details about the ongoing activity at Huila in Colombia, including a video report from the BBC. It seems that the eruption at Huila is a photocopy of what happened at Nevado del Ruiz in 1985 in its style: hot ash and gasses erupted from the crater melted ice/snow near the summit to create a lahar - a deadly mix of volcanic material and water that ends up like a surging flow of liquid concrete. The lahars travelled down the Rio Paez valley (see linked map - the landslide on the map is not volcanically related).
Beyond the unfortunate victims caught in the mudflows, many…
eklemetti | November 23, 2008Â
Klyuchevskoy has already had a busy year and now we have some recent photos showing a lava flow that is snaking down the side of the volcano. The website with the lava flow image has a pile of other great eruption photos of Klyuchevskoy over the last couple of years and well worth the time to look through them all - the volcano is definitely one of those classic arc volcanoes in both shape and activity.
eklemetti | November 22, 2008
Eruptions and earthquakes go hand-in-hand a lot of the time. It only makes sense as magma needs to move under the crust, causing movement (i.e., earthquakes). Additionally, any sort of explosions caused by the release of volatiles might cause earthquakes or even the collapse of an edifice (which in turn, shakes the earth).
So, it is not surprising that the current eruption at San Cristobal in Nicaragua has produced earthquakes. The reports are relatively lacking in details, but San Cristobal is a typical Central America stratovolcano that produces frequent Strombolian style eruptions, which…
eklemetti | November 22, 2008
I have been out of town for the past few days, but we do have some big (and unfortunate) news from Colombia. Nevado del Huila in southwestern Colombia erupted today and the ensuing lahar (or volcaniclastic debris flow - it is hard to tell from the reports) killed at least 4 people, and possibly as many as 10*. We know that Huila has been showing signs of activity, but now it seems like it might have had real eruption, at least to the point that a lahar was produced and possible the creation of a new summit crater. Evacuations are under way and several towns have been cut off as the lahars…
eklemetti | November 17, 2008
So, I get a steady diet of email messages here at the Eruptions HQ, so I thought I could try a little roundup of the great information/links that you readers are sending (and I apologize for taking so long for some of these). Enjoy!
- Tim Stone tells us about GeoEye pictures of volcanoes. GeoEye is the new satellite launched to add to the Google Earth images of the planet. There are some quite striking images of volcanoes included in the collection.
- Richard Roscoe sends us to some updated images of the on-going volcanic activity on Montserrat. As usual, there is an abundance of excellent…