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…
eklemetti | November 17, 2008
Redoubt Volcano, in Alaska, is one of the more troublesome volcanoes in the state. Not only is it relatively close to population centers, but it also lies directly within the aircraft corridors above the Aleutians for planes headed to Asia and beyond. This means that USGS and AVO geologists have to be especially vigilant in watching Redoubt's every move.
Currently, the volcano has been recently changed to a yellow (elevated) alert, due to increased steam/volcanic gas emissions (remember, the number one volcanic gas is water vapor) at the volcano. So far, there haven't been any reported…
eklemetti | November 13, 2008
Just a brief note, but today (November 13) is the 23rd anniversary of the disastrous lahar at Nevado del Ruiz in Colombia. Over 23,000 people died when a lahar, started by a relatively minor eruption of the volcano, swept down the river valleys the side of the edifice and destroyed Armero and Chinchina. The footage of rescue efforts after the lahar were devastating and heartbreaking (caution: linked video might not be for the faint of heart). Sadly, this disaster was mostly preventable as the citizens of these towns could have had at least an hour's warning to walk to higher ground, but the…
eklemetti | November 11, 2008
El Reventador, the composite volcano in Ecuador, has been producing explosions and ash for the last few days, so says reports from the country's  Geophysics Institute. El Reventador is only 100 km from Ecuador's capitol, Quito, and in 2002 the volcano blanketed much of the city in ash. However, the eruptions currently occurring are much smaller and limited in scope, producing ash and throwing incandescent blocks out near the vent (see above). No evacuations are currently planned. These types of eruptions are typical for El Reventador since 2002, with increased activity every few years…
eklemetti | November 11, 2008
I just got back from a 4 day field trip to the Long Valley Caldera in eastern California, so I'm a little behind on posting. The field trip was great and I had a chance to see a lot of pumice, a lot of welded tuff (in the form of the Bishop Tuff, the large ignimbrite that erupted from the Long Valley Caldera ~760,000 years ago) and got to lead the part that looked at the Mono domes (too bad snow covered the Inyo Domes). Pictured above some puffed obsidian - the layers are obsidian and vesicle-rich obsidian - that were erupted, cooled, expanded and cracked (known as "breadcrusting"). This is…
eklemetti | November 6, 2008
One of Kamchatka's most active volcanoes is continuing to erupt. Shiveluch, in the northern part of the Kamchatka Peninsula in Russia, produced a 26,000 foot (~8,000 meter) ash column today (November 6) as the eruptions that started in 2006 persist. The reports suggest little danger to people living on the peninsula, however the ash column is causing problems with the air travel over the region (an important corridor for trans-Pacific travel).
eklemetti | November 6, 2008
Sounds like we're beginning to get a better idea of what is erupting in Ethiopia. Ghezahegn Yirgu, a geologist at Addis Ababa University, reports that Dalla Filla Dalaffilla Volcano is the source of the eruption. Again, the eruption is being characterized as "lava flows" rather than an explosive eruption, which may be surprising considering the amount of volcanic gases being released (see Boris Bechnke's highly useful comment). However, some mostly effusive eruptions have released a lot of volcanic gases in the past - see Laki, Iceland in 1783 - so a preponderance of flows at Dalla Filla…
eklemetti | November 5, 2008
In one of the most oddly worded articles I've seen from the BBC, a lava flow from Erta Ale an unidentified volcano in the Erte Ale range in Ethiopia has erupted a significant amount of lava. The headline states "Ethiopia volcano sets lava record", which is strange on multiple counts, but mostly because I'm not familiar with any "lava records", who might keep track of them and what, exactly, this "lava record" is. In fact, they don't even mention it in the article itself. They do, however, point out that lava from this eruption has covered 300 square kilometers, which is a decent chunk of…
eklemetti | October 31, 2008
After nearly a year and a half of little lava dome growth at Soufriere Hills in the West Indies, this past July 26th, the volcano erupted new dome material. Why do I remind us of this, you ask? Well, the Scientific Advisory Committee at Montserrat feel that the dome growth might be restarting in earnest:
Since August, any new supply of lava has been minimal. Thus while there is evidence that the eighteen-month long pause in lava dome growth may be coming to an end, it has not happened yet.
The most troubling event, in their minds, is the new activity at the Gages Wall vent, which means that…
eklemetti | October 27, 2008Sorry about the dearth of posts. It has been a busy week here in Davis and I've been a little distracted by the upcoming election. Combined with the relative lack of volcano news this week, the posting has been lackluster.
However, that being said, I will try to make up for some of it by starting my Volcano Profiles series that will bide the time between volcano news. I start with a volcano that was suggested by Eruptions reader Thomas Donlon: Rabaul.
VOLCANO PROFILE: RABAUL
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Location:Â Papau New Guinea
Height: 688 m
Geophysical location:Â Boundary of Australian plate and Pacific plate…
eklemetti | October 20, 2008
The headline for this entry sounds more dramatic than it is, but one of the last structures in the ill-fated Royal Gardens subdivision on the big island of Hawai'i finally met its fiery demise over the weekend. For those of you unfamiliar with the plight of the subdivision, Royal Gardens is part of Kalapana, and it was unfortunately situated quite close to the Pu'u O'o rift that has been erupting since 1983. Most of the subdivision has been overrun by lava flows since then, but one of the last two structures still being used was done in by the basaltic lava. The first link has a great map…
eklemetti | October 17, 2008
The only volcanic arc in the lower 48 states continues to be pretty darn quiet according to the USGS. The Cascade range that spans from Lassen Peak in the south to Mt. Baker in the north (and maybe Mt. Garibaldi in Canada) has been remarkably quiet in terms of eruptions for the last century. In fact, only Mt. Saint Helens and Lassen Peak have erupted since 1900 - and most of the volcano have shown very few signs of even coming close to eruption beyond minor seismic swarms, steaming or land deformation. This is in contrast to the reports from the 1800s that suggest that Hood, Shasta, St.…
eklemetti | October 16, 2008
Reports from Russia indicate that Klyuchevskoy, Russia's largest volcano, is erupting. It sounds like it might not be just a murmur as Alexei Ozerov from the Institute of Volcanology and Seismology of the Far Eastern branch of the Russian Academy of Sciences says the volcano is spewing ash, rock and gases. No real details on how tall the eruption column is, but the report mentions a hazard to aircraft in the area, which would suggest that the column is at least in the 3,000-5,000 meter range. Klyuchevkoy is part of the Kamchatka volcanoes in far east Russia and last saw a major eruption…
eklemetti | October 15, 2008
There isn't really much information in this report, but Galeras in Colombia has been put on "high alert" for a potential eruption. The volcano did emit a ~2,400 meter steam (and ash?) column today, but beyond this, it is unclear what else might be happening at the volcano.
Galeras is the most active volcano in Colombia, having erupted frequently in the past decade, producing mostly ash falls, ballistic bombs and other explosive volcanic products. It is also located within a few kilometers to Popayán (see photo above of previous activity), a city of ~200,000 people, making it a potentially…
eklemetti | October 13, 2008
The eruption of Kasatochi was a bit of a surprise to volcanologists who study the Aleutians, to say the least. The volcano itself has been quiet for likely over 100 years, but with relatively little warning, the volcano erupted over the summer, blasting ash (and a large amount of sulfur dioxide) into the atmosphere. We finally have some images of the destruction wreaked upon the island, and from the looks of it, the island is blanketed in grey ash from the eruption(s). Biologist who have worked on the island prior to the eruption think a significant number of auklets may be buried in the ash…