Eruptions

Soufriere Hills continues having a big winter

Category: Soufriere Hills

A pyroclastic flow from the February 5 vulcanian eruption of Soufriere Hills. Image courtesy of the Montserrat Volcano Observatory (MVO).

One event that didn't eat much coverage over the weekend, at least here in the U.S., was the large eruption and explosions at Soufriere Hills on Montserrat. The volcano has had a resurgent winter since have a quiet summer of 2009. This weekend's eruption produced an ash plume that reached ~6.1 km / 20,000 feet - which has been happening quite a bit over the last month or so. However, this eruption produced an large pyroclastic flow that reached the former capitol of Montserrat, Plymouth and 500 meters (not miles as one report states) into the sea. This eruption would technically be a vulcanian eruption according to MVO and prevailing winds prevented ash or lapilli from falling on the eastern half of Montserrat. This eruption was likely related to the collapse of the growing summit dome. MVO has posted a thermal video of a previous vulcanian event on January 7-8, showing the collapse/explosion from the dome and the pyroclastic flow generated - both made of hot (>500 C). The latest information on the current activity from Soufriere suggests that the central western part of the dome was growing steadily before the vulcanian event over the weekend, but there is yet to be another observation of the dome to see if that has changed.

Posted by Erik Klemetti at 4:25 AM • 0 Comments • 0 TrackBacks

Help me find a video!

Category: Volcanic hazards

This is a request more related to my teaching, but I thought I'd ask here. I'm trying to find copies of the UNESCO videos "Understanding Volcanic Hazards" and "Reducing Volcanic Risk". They were made by the Kraffts to help educate people on volcanic hazards, especially in developing countries. I've seen them both and they are great for introductory geology classes. However, the one source I knew of - the NW Interpretive Assoc. - doesn't seem to carry them anymore - and even if they did, the only format I know of is VHS, which is getting woefully obsolete.

So, do any of you know where I might be able to get a copy of either/both of these films, either on VHS, DVD or otherwise? Leave a comment here or send me an email at Thanks for any help!

Posted by Erik Klemetti at 5:20 PM • 13 Comments • 0 TrackBacks

Laacher See: The caldera in the middle of Europe

Category: Laacher See

We've been discussing calderas recently on Eruptions (I wonder why) and the Laacher See in Germany came up. I've actually been to the Laacher See on a field trip lead by one of the world's experts on the caldera, Dr. Gerhard Worner. So, I thought I'd post some pictures and talk a little about this feature that up until maybe 5 years ago, I didn't even know existed.

Laacher See, Germany
The Laacher See is a caldera in the Rhine Valley of Germany (see below). It is only ~30 km south of Bonn and ~60 km south of Koln (Cologne), just to the west of the Rhine River. It is part of the East Eiffel Volcanic Field and the 8-km wide caldera is currently filled with a lake. Now, most people don't think of volcanic activity occuring in central Europe, but it is believed that a mantle plume lies below this part of the continent, creating rifting and the volcanism in the Eifel Volcanoes. Laacher See last erupted ~12,900 years ago, but it was a doozy, erupting ~6 km³ (dense rock equivalent, i.e., taking all the ash and compacting the air out of it; closer to 20 km³ of uncondensed) of phonolite (an silica-undersaturated magma found in continental rift zones) tephra, making it similar in size to Pinatubo in 1991. Phonolite tends to have some odd minerals in it, such as the light blue feldspathoid, Hauyne, but the Laacher See magmatic body appears to be a complex mix of crystals from different sources.

The ash from the eruption can be found in the North Sea and throughout central Europe. Some of the deposits found near the caldera is remarkable, and (to me) seem so anomalous for the middle of the German countryside. There is some suggestion that the Laacher See eruption could have had a strong effect on the climate of Europe after the eruption and the human populations living there at the time. Although it has been quiet since the climactic eruption ~12,900 years ago, the caldera should still be considered potentially active as CO₂ seeps exist in some parts of the lake, suggesting that there is still magma degassing under the lake. In fact, the CO₂ can be a hazard, supposedly killing some Medieval monks in their sleep. There is no hazard map for Laacher See.

Here are a few pictures from my trip to the Laacher See (as a part of the 2007 Goldschmidt Meeting in Cologne). Click on the image to get a bigger version.

Pumice from the 12.9 ka Laacher See eruption at the Standort Wingertsbergwand, a quarry near the caldera. Note the trees at the top of the ridge for scale.

This is the plucky mascot that guided us to the deposit.

A close up of the tephra deposits showing the beautiful layers of ash, pumice and lithics. This is a record of the pyroclastic flows and ash fall from the multiple days of the Laacher See eruption.

Another view of the stunning tephra deposits.

Dr. Worner points out some of the features of the tephra deposits.

Dr. Worner uses a hand-made sampling device (i.e., a cut up soda bottle) to gather some of the volcanic gases - mostly CO₂ bubbling up on the shores of the Laacher See. You can see the bubbles in the foreground in the shallow water.

A view across the caldera lake. You can see the Maria Laach Abbey on the opposing shore.

And really, what a better place to end the day than at a Brewery that keeps its beer in an underground basalt flow.

Posted by Erik Klemetti at 4:12 AM • 36 Comments • 0 TrackBacks

How KVERT got its groove back (temporarily)

Category: Volcanoes and the economy

Shiveluch in Kamchatka in an undated photo.

Just a quick note, but I got this email overnight regarding the status of KVERT, the Kamchatka-Kuril Island volcano monitoring body in Russia.

Scientists of KVERT Project return to the full KVERT operations (the
information ensuring of air services for the results of daily analysis
and evaluation of activity of Kamchatka and Northern Kuriles
volcanoes) and will discharge these obligations for 01 February - 30
April 2010.

So, after losing their funding, it has some back until the end of April (based on how I read this). Russian politics as usual? A window to get real funding in place? Who knows, but at least for the time being, KVERT is up and running again.

{Hat tip to Eruptions reader Tsunami for also bringing this to my attention.}

Posted by Erik Klemetti at 9:00 AM • 4 Comments • 0 TrackBacks

Friday Flotsam: Yellowstone slows down, Pakistan eruption clues, NASA images and "Volcano Hell"

Category: Africa

News!

Pakistan is home to the world's tallest mud volcano in the region of Balochistan - and its somewhat near the reports of an "eruption" earlier this week.

• Guess what? Since Wednesday evening, seismicity at Yellowstone has dropped precipitously. The last batch of earthquakes on February 3rd were also back to deeper levels - 8-9 km depth - compared to the potential shallowing earlier in the week. I'm sure the caldera will keep us on our toes, but as of now, it seems to have settled down a bit.
• Over in Pakistan, there is mounting evidence that the recent "volcanic" eruption reported as, in fact, a mud volcano similar to the one reported in Azerbijian yesterday. There can be explosions associated with mud volcanoes as trapped natural gases escape and (potentially) ignite. There is a long history of mud volcanoes in Pakistan, especially in the region where this eruption was reported.
• In case you missed it, frequent Eruptions commenter and part of the Italian National Institute of Geophysics and Volcanology in Catania, Dr. Boris Behncke, was on the Discovery Channel show Solving History. He was talking about Mt. Etna in a part of an episode looking for Atlantis (?) - the segment is called "Volcano Hell" (nice touch, eh?) Sadly, they aren't streaming the part with Dr. Behncke in it (so Boris, has Etna been "wreaking havoc on Europe" as Olly says?) Now, if only someone would give me a call to be on TV... {hat tip to Doug for point this out.}
• The NASA Earth Observatory has a few good images to send us into the weekend. First captures the swirling ash clouds from the revived Soufriere Hills on Montserrat. The second shows the beautiful snow-covered symmetrical cone of Karymsky filling the old caldera that surrounds the new edifice on the Kamchatka Peninsula.
• Finally, lost in all the Yellowstone, Pakistan and Japanese volcano news, the latest USGS/Smithsonian Weekly Volcano Report was issued. One of the interesting things it points out is that after all the activity in January of Nyamuragira, its neighbor Nyiragongo is now showing signs of an impending eruption.

Posted by Erik Klemetti at 4:50 AM • 66 Comments • 0 TrackBacks

"Eruption" in Azerbijian

Category: Lok-Batan

A 2010 mud flow from Lok-Batan, a mud volcano in Azerbijian.

So, first there was all the Yellowstone talk. Then the unsubstantiated reports of a volcanic eruption in a decidedly unvolcanic part of Pakistan (what part isn't), then submarine volcanism off Japan. Now, we have a nrews report about an eruption in Azerbijian. Luckily, although the headline implies a magmatic event, the text of the article shows that this is, in fact, a mud volcano. The mud volcano is called Lok-batan (or Lokbata) and has erupted quite a few times over the last 150 years, as recently as 2005. Azerbijian has quite a few mud volcanoes, some of which are quite impressive. Remember, "mud" in the ground is just a viscous fluid - water and soil more or less - so it too can behave like lava if it becomes pressurized, especially thanks to heating of the mud. Earthquakes (common along the shores of the Caspian Sea in Azerbijian) could provide a route to the surface for the pressurized mud, leading to the "eruption". The most famous mud volcano in the world is like the Lusi Mud Volcano in East Java, Indonesia - a feature that was likely triggered by man-made action.

Quite the volcano week, eh?

Posted by Erik Klemetti at 10:14 AM • 5 Comments • 0 TrackBacks

Submarine eruption near Japan

Category: Fukutoku-Okanoba

The plume from submarine volcano Fukutoku-Okanoba, erupting in February 2010.

Almost a year after the Hunga Tonga Hunga Ha'apai eruption, where an undersea volcano sprang forth from the deep - quite spectacularly, we have new footage of another undersea eruption. Fukutoku-Okanoba, off the coast of Minami Iwo, started to erupt yesterday (or, at least, erupt enough to manifest a plume out of the ocean). A Japanese coast guard vessel was able to capture the plume on video as it reached 100 m / ~300 feet. The plume appears to be dominated by white steam along with some grey ash mixed in. Additional footage shows the water stained brown/tan with ash and volcanic debris from the eruption as well.

Fukutoku-Okanoba is actually a quite active submarine volcano, last erupting in 2005. The sea is often discolored near the volcano and a number of ephemeral islands have formed due to its activity over the last 100 years - my favorite being Shin-Iwo-jima, or "New Sulfur Island" in 1904. Most of the eruptions appear to be VEI 0-2 based on what manifests at the surface, however the 1904 eruption was VEI 3, producing significant andesitic (intermediate) ash and lava. The summit of the volcano lies only 14 m / ~50 feet below the ocean surface.

Posted by Erik Klemetti at 8:45 AM • 4 Comments • 0 TrackBacks

Looking inside the structure of the Yellowstone Caldera

Category: Yellowstone

With all the talk of the current Yellowstone earthquake swarm, I thought it would worth it to write a post on the the structure and caldera - and why we get earthquake swarms that are structurally rather than magmatically-related.

First off, lets think about why calderas formed. This is relatively simple - at least superficially. The land (or volcano) above a magmatic system is partially supported by that magma, especially because magma is hot and buoyant. The isostatic support by the magma holds up the land surface or volcanic edifice, so when an eruption expels a large volume of magma, this support is removed. This collapse forms the caldera - the negative topographic expression of the eruption. The collapse of the land surface plays a dual role - not is it a result of the eruption, but also helps the eruption along, like a piston pushing of hot gas out of a cylinder. After the eruption, the collapsed caldera continues to subside as the isostatic equilibrium is reached. After the caldera-forming eruption {caution, large PDF}, the system may have eruptions that produce resurgent domes in the middle of the caldera as the last dregs of the caldera-forming magmatic system leak out. This is referred to as the "caldera cycle", originally defined by Howell Williams for the collapse of Mt. Mazama ~7,700 years b.p. (see below).

Modified illustration of the caldera cycle by Howell Williams.

The collapse of the caldera produced what is called the "ring fracture," the fracture along the edge of the caldera. This fracture was formed during the collapse, but was then likely also exploited by the erupting magma during the caldera-forming eruption. These fractures then become long lived zones of weakness around the edge of the caldera (see below) - the down-dropped part of the caldera is no longer supported by either the emptied magma chamber or the crust around it.

Map of the extent of Yellowstone Caldera. The ring fractures from the caldera-forming eruptions are roughly coincident with the caldera.

We can look at the general structure of caldera systems by looking at the Long Valley Caldera (see below). The ring fracture is present on the edge of the Long Valley caldera, with the down-dropped caldera material in the middle - filled in by the tephra from the caldera-forming eruption and resurgent dome material. The caldera may continue to settle for hundreds of thousands of years after the caldera-forming eruption - all happening at depths at or above the current "top" of the magmatic system.

A schematic look at the structure of the Long Valley caldera in California.

If we take a look at historical seismicty around Yellowstone (see below), we can see that quite a bit it is near the ring fracture of the caldera. This means that thesuggested structural source of the current seismicity makes sense - as I've mentioned, the earthquakes in these locations in historic times have not lead to eruptions. In fact, we should expect to see a lot of low scale seismicity along the ring fracture that represents the many faults related to the ring fracture system.

Historic seismicity around Yellowstone Caldera.

However, as zones of weakness, you might expect that magma could exploit the ring fracture to reach the surface. Magma rising would need corroborating evidence, though. Magma doesn't do a good job of disguising its present, especially large volumes. The ground should deform from the additional volume of magma displacing the crust and this displacement with our current methods of measuring ground changes should be detected well in advance of an eruption. We should also expect changes in the hydrothermal system as the hot body of magma moves higher into the system, possibly in the form of new mud pots, geysers or hot pools. The chemistry of springs might change as well, reflecting the input of magmatic components into the water - which goes hand-in-hand with changes in gases being released by the magma. Volatiles like water vapor, CO₂, SO₂ and He are constantly being released by a cooling, depressuring magma, so we should see the signal of this in the gases being released at Yellowstone, especially by monitoring dissolved gases in springs. The type of earthquakes should also change - not only becoming shallower, but also taking on the classic pattern of harmonic volcanic tremor - the harbinger of moving magma.

YVO monitors many, if not all, of these factors, so we are not likely to be "surprised" by any new eruptions at Yellowstone. While the current earthquake swarm does appear to be getting shallower, you can see how it is part of life at an active caldera system. You can check the current status of the Yellowstone Caldera on the YVO website.

Posted by Erik Klemetti at 4:07 AM • 34 Comments • 0 TrackBacks

The Yellowstone Earthquake Swarm of 2010 marches on

Category: Yellowstone

Steaming, gurgling mudpots in the active hydrothermal system of Yellowstone.

For those of you following Yellowstone (I think there might be a few of you), I've plotted up the earthquakes since 1/27 (see below) - and sure enough, although there is a lot of scatter, they are getting shallower - however what this exactly means is unclear. You can see my plots from 1/22-28 here. As many of you have mentioned, a caldera like Yellowstone is a big interconnected system, so a solely tectonic source of this is still possible as the displacement migrates through the fractured caldera rocks.

UPDATED: Now with error bars! The line divides the well constrained (to left) from the poorly constrained (to right).

This all being said, YVO's current status statement still reads:

" At this time, YVO scientists and their collaborators have detected no anomalous ground deformation, strain, or increased thermal activity that could indicate precursory activity to phenomena such as steam explosions or volcanic eruptions. As such, the Volcanic Alert Level remains at Normal (Aviation Color Code of Green)."

So, again, without abundant evidence to suggest otherwise, the swarm has shown no indications that this is magma related. The earthquakes are shallower right now, but again, we need to look at this information with an abundance of caution. YVO posted yesterday a summary of the current earthquake swarm and an brief history of swarms to put this one in context along with a description of all the monitoring that occurs at Yellowstone - so if you are concerned about the swarm, be sure to check it out. This caldera is not solely a magmatic feature - the process of caldera-forming itself involves breaking the crust along a ring fracture. This means that the area is littered with thousands (millions?) of fault systems related to the caldera. Trust me, I'd be fascinated by the idea that a new dome might be erupting at Yellowstone (i.e., NOT A SUPERVOLCANIC ERUPTION), which is the mostly likely scenario, but until the evidence tells me otherwise, this doesn't look like it.

Posted by Erik Klemetti at 8:56 AM • 25 Comments • 0 TrackBacks