Monday Musings: Excavating Toba and the Yellowstone swarm summary


Toba caldera in Indonesia.

  • We're all still talking about the Chilean earthquake and the coverage of the event. If you happen to live in the Columbus area, you might have heard me on WTVN talking about the earthquake as well.
  • The Toba (Indonesia) eruption 74,000 years ago has been used by some researchers to be the cause of a "genetic bottleneck" for humans - however, that is still much debated. Currently, excavations are under away near Toba to look for evidence of human habitation that was buried by the eruption. The evidence of stone tools that appear to be made by the same human populations before and after the eruption suggest that the eruption didn't have as profound an impact on human populations as previously suggested.
  • If we didn't know it already, the recent Yellowstone earthquake swarm is now officially the second-largest on record. YVO says that the swarm had no noticeable effect on the caldera's geysers or surface uplift. In total, the swarm released the equivalent energy of a single M4.4 earthquake.
  • And if you're looking for a couple volcano-related vacation spots, there are a couple of articles on tours of Hawai`i and the Oregon High Lava Plains. You know, summer is around the corner, right?

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First and most important bit of news, the folks I know in Chile - who live actually in the area strongly stricken by the 27 February M 8.8 earthquake - lived through it unscathed but described their apartment as "looking like having gone through an air attack" and the earthquake itself "hell". Luckily these people were prepared, having a vast amount of spare water in a container, spare foof, flashlights and other useful items.

About the recent Yellowstone earthquake swarm it would be correct to say it was the second-largest since the start of instrumental monitoring, whereas the press report cited above describes it as the "second-largest ever". One more time, some slight (intended?) lack of precision in a news headline makes things appear more dramatic than they actually are.

And here's a link to the "Toba Project" by University of Oxford scientists that the second paragraph is about: (unfortunately they also use this misleading term "supervolcano")

As for the summer around the corner, the weather in Sicily very much confirms this. Maybe the US have had an unusually cold and/or snow-rich winter this year, but in Sicily this has been the mildest winter since I moved to this island roughly 15 years ago.

@Boris: glad to hear your friends are ok.

I read someting about an investigation going on in India (I think, maybe it was near Toba) where they found the same kind of tools before and after an eruption. I think they were talking about the Toba eruption. I saw the blurb about that on the science/technology part of MSNBC, and, yes, I know they sensationalize stuff ,but the article I read was very interesting. Just goes to show how much we don't know until we start digging.

Just checked the article on the Toba ash dig and it is the one I saw and they are doing the dig in India. Very interesting.

Wish I could go to Hawaii. Oregon is much closer. :-)

Awwww darn Boris I was heading out to get me some foof just in case:) I really wish there was a spell check on our comments myself. Glad to hear your friends are ok..I know you are relieved. I am sending that link you posted to my Dad(architect). He lives in Northwest Alabama and for the most part designs schools, prisons and churches. He said that when he was in school at Auburn back in the 60's they didn't even teach anything about earthquakes but now at least the public buildings have minimum seismic codes.

The Oregon lava fields are very cool to explore.

Modern geology and engineering science, application and practice got a thorough testing on Saturday in Chile, a developing nation in a geologically active region that is arguably in the top three or four for large rupture risk. Considering the power and duration of the quake and numerous aftershocks, structural damage and loss of life estimates in large urban centers was surprisingly low.

Thanks for the article link, Boris.

@Randall: so you want some of that "foof" too, eh? Must be some kind of new Italian, oops, I mean Chilean cuisine.

Like I said before, typos allowed here. LOL

I checked the link to Oregon and my DH and I were right into that area when we went to see his sister and we stopped at the large cinder cone on the way back and took pictures. We then went to the center and talked with the people there and I asked if they had a piece of that cinder rock that I could have for my collection. They were nice enough to give me a piece! That was pretty cool. I would like to go back there again and look at more stuff. Some day maybe. It is a large area.

Gijs - Ha! Yup, you found the video the folks at Denison filmed in my class. Not volcanically-related, but amusing to some I suppose. I honestly haven't watched it mostly because its darn hard to watch yourself on TV.

Yeah, I know :P . There was once some footage of me teaching a class on youtube, but after it had lost its use (me and some fellow students had to prove ourselves 'competent' at some teaching skills) I had it removed ;-) .

Chalkboards are still common at Denison? We've switched to smart boards and occasionally a whiteboard ;-) .

About volcano travels: there's a small Dutch company that specializes at that:

A lot like John Seach's work I guess

By Gijs de Reijke (not verified) on 01 Mar 2010 #permalink

@Erik, great illustration technique! I have another one for you on a different subject: liquifaction. You probably already know about it, but I discovered it when I was working on some of our concentrates for gold panning. What I did was shake some of the sand in the bucket down and here came the water up on top of the sand. Hmmm. It may look like there isn't any, or much water in damp sand, but if you shake the bucket back and forth, the sand sinks and the water comes to the top. And there you have liquifaction. May not be exciting, but I though it was kind of neat to see it even if it was only in a bucket.

While I've visited eastern Oregon a number of times, I'll never forget my first trip through the region as a young teenager. Starting at Mount Lassen, I'd spent three days being inculcated with images and tales of disastrous, explosive volcanism as we traveled north through the Southern Cascades to Bend. I went to bed each night with my head full of details from the ranger-led talks, hikes, visitor center dioramas, and vivid literature I'd voraciously absorbed. When we spent one night on the rim of Crater Lake, I was in the midst of a dream that Mount Mazama was again coming to life. A low-flying military jet broke the sound barrier immediately above us. You can be sure everyone at the caldera rim thought the volcano was exploding! People poured out of the hotel, cabins, and campgrounds--all of us scared out of our wits! By the time we arrived in Bend a day later, I was experiencing nightly volcanic nightmares. I couldn't even complete our tour of Lava River Cave because my imagination had gone into igneous overdrive by then. In hindsight, of course, I relish the memories of that trip. Now that it's easy to laugh about it. [Said she, nervously.]

Beautiful how the shockwave of the blast moves through the steam cloud...

By Gijs de Reijke (not verified) on 01 Mar 2010 #permalink

Eying patterns of moderate-large EQ activity on the USGS current quake map, its an interesting exercise to sketch in nearly lines of failure progression along the Apenide Belt. Extending the upper line puts potential in through Greece and into your neighborhood, Boris.

Not saying anything is going to happen, just playing with sets of parallel activity lines, given the jump in recent activity in conjunction with unusual record precip to the north in late winter. Beijing got socked with 50-yr record snow this weekend, Moscow with an unusually heavy snowfall last weekend.

Interesting clustering.

@MJKBK, I guess you can laugh about it now. I have been to Lassen also and we listened to a ranger explain how Lassen came up after MT Tehema blew. Broke Off is part of the rim. There really isn't a caldera there, but it is an interesting place. I have had the opportunity to climb Lassen twice.

I remember the first time we went to Crater Lake. I saw the Milky Way for the first time(I was very young) and I asked my dad what it was. I wanted to go down the trail to go on the boat ride, but Mom didn't want me to. She also wouldn't let me go into the Oregon Caves when you could take your own light in and explore on your own. I would have been with my dad and brother for crying out loud! Anyway, I would love to go back to Oregon and take a look at some more of that stuff. DH and I did go to Crater Lake and it was beautiful and part of the road was still closed because of the snow. We had a pretty good time in Oregon, but we didn't spend enough time there.

I have been a volcanophil since at least 8yrs of age. Probably before that as I have been a rockhound from the time I could walk.

@Passerby, I will have to check out the quake map to see what you are referring to. Where is the Apenide Belt?

Just checked the map at Mammoth Mt and there are ~43 quakes in the vacinity of the mountain. All of them seem to be below 1.0 mag. I just did a quick count and check of the mags and that is what I came up with. In total, for the area which includes the Long Valley caldera and also quite a distance south of the caldera, there are 70 listed.

The area around Coso Junction has 62 quakes and the largest is a 3.8. They took off the 4+ because I guess it was not a quake.

I forgot to mention that the increase of quakes over the years since I have been monitoring them includes the man-made quakes from the Geysers area where they are reinjecting water into the system to generate power. So out of 735 quakes listed on the map right now, 280 are in the area of the Geysers power plant. It includes a lot of territory, but I would say that about at least 250 are from the reinjection project. So I would say those quakes don't count in the overall increase of quakes in CA. As I have said, I remember when there was only 250 quakes listed for the entire state for a week! Since we have better equipment now and the geopower plant we have more on the list. Probably an average of 450-550 not counting the power plant.

@Passerby, I checked the map and I think I know where you are talking about.

@Diane. Yellowstone gets all the press doesn't it. This Long Valley thing has be going on a long time.That and the CO2 tree kill is interesting. If the quakes get up in the 2-3 range then things may start a popping.
The locations are most often at a depth of 3-5km...very shallow. Maybe water in the system.

By dasnowskier (not verified) on 01 Mar 2010 #permalink

Look for basin precipitation correlation to swarm frequency changes. I realize that 'correlation is not cause' is a..ahhh.. dirty phrase for you, but if geothermal plant reinjection is causing quakes in an active geothermal system, heavy seasonal precipitation loading is very possibly culpable as well.

Mammouth Mt just picked yet another 32+ inches this weekend, with quite a bit of rain at lower elevations.

Next equidistant step, northern line, is near the edge of the Aral Sea in Khazakhstan. Southern line nexus is Iran, Alborz Mts. Lucky they are all moderate shakes.

Has to be coincidence, chance.

Whoa. Southern Alpide transect, SE end, earthquake just posted, on point, in a nearly equidistant grid.

Its like either end of this parallel band system is pushing out from a centroid.

Cannot be. There is no such thing as a linear response in this type chaotic system. Very cool coincidence, though.

Found this.

Earthquake theory stretched in Central Asia study
Feb 2008

"Using computer modeling, the researchers were able to show that the long, hard boudin that sits vertically beneath the Hindu Kush is being stretched as its lower parts are pulled into the Earthâs mantle. âItâs like a metal rod that is being pulled at both ends,â Professor Lister explained. âEventually the stretching will suddenly accelerate, releasing energy in the process.â

@Passerby, "correlation is not causation" is not a dirty phrase for me. I'm sorry you thought it was. It just means that correlation doesn't necessarily mean a direct cause of something. That is the point I was trying to make as some others have said also.

Anyway, the geopower plant is not even near Mammoth Mt. It is SW of Clear Lake north of SF and part of the coastal range. It is an active geothermal area that had geysers (not sure if they do now or not) and Mt Kenocti is a volcano near Clear Lake. I have not done any study on the area, but I do know it is active. In the upper Napa Valley there is a geyser they call the Old Faithful of the west. It goes off irregularly, but often, and actually lasts longer than Old Faithful in Yellowstone. You can get close to this one, too, as in maybe about 20'! There are fish in the pool that surrounds the geyser hole, grass around that and picnic tables. It is not very far from Howell Mt. which is supposed to be an extinct volcano. With a geyser only a few miles from it by way of crow, I have my doubts and there is a town with a college in that crater. I think the reason they say it is extinct is because there is supposed to be water below the floor of the crater. Another volcano in the area is Mt. St. Helena which is supposed to be dormant. It is in the northern end of Napa Valley. I guess I should check out the geology of that area. I spent some time over there and never even thought about it at the time.

I know in the area near Clear Lake there are some mercury mines that have been covered over so no one can get into them. I know a guy who used to work in them.

As for Mammoth, there is a lot of CO2 being released there and it is killing the trees. There could also be some water in the mountain that is causing some of the activity. There are also at least two faults there so the quakes may be techtonic. I do know that some of them are. I don't know the direct cause except there are more than there used to be.

There has also been a swarm up at Lassen. It is quiet now, but once in a while there will be a few. The swarm had 90 at one point and some of them were in the 1.5-2.0 range. Someday, Lassen will erupt again, even though it is a plug dome. It is dormant right now. The quakes were just on the SW flank.

That's about all I have for now. I am going to take a look at the geology around Clear Lake and upper Napa Valley.


Ok. I checked what I could so far about the area around Clear Lake and Mt. St. Helena. Mt. Konocti is inactive. The volcanics from Mt St Helena are silica rich and there is obsidian in the area as well as pyroclastic flows. The obsidian was erupted explosively and I think the petrified forest that is out of Calistoga was created by one of the pyroclastic events (if I remember right). That is an interesting place to see, also.

What has been aggrevating is that I typed in geology for Napa Valley and all I get is info about wineries. ARG! I will keep looking.

BTW, Mt St Helena is part of Robert Louis Stevenson Park. You can climb it and the trail is 5.5 miles long and moderately difficult.

More as I find out about it.

Nothing wrong with wineries Diane ;-)

@ Thomas Wipf - übercool video! Amazing how much lightning you see in the cloud even in daylight. Thanks for the link!

By bruce stout (not verified) on 01 Mar 2010 #permalink

What a wonderful place, made for an intriguing headline: "Mt Konocti. Magic, Myth and Magma"! "Persistent local belief holds that Konocti's central magma chamber is a vast, empty vertical cavern, partly filled with Clear Lake water and connecting with the lake via an underground seep. This cavern might be the largest on Earth, though its existence is difficult to prove due to the unstable and eroding structure of the volcano's cone."

Costa Rica's volcanoes have not been entirely quiet these days - Poás had a small phreatic explosion on 23 February…
there has been a small swarm of earthquakes at Irazú on 1 March…
and the OVSICORI has posted spectacular aerial photographs of Poás and Arenal taken on 24 February

Boris Yeah my girlfriend and her cousin just got back from Costa Rica and said they felt a quake when they were in San Jose...I think what she felt was the 5.6 in Nicaragua on February 25. I have got to quit hanging out here as much now that she is back....I think she is getting a little jealous of this site;)

@Boris, the OVSICORI site is unsafe according to my Norton program. I don't know what is going on with that, but you may want to run your antivirus program. Norton told me there were 4 problems so I just wanted to let everybody know. Great pics what I could see of them before I got out of the site.

@Bruce, Nothing wrong with wine, unless you don't drink, which I don't. DH is a recovering alcoholic 27 yrs sober. I am proud of him. I must say the area around the town of St. Helena is very interesting with all the wineries. Some of them are dug into the rock hillsides and have a relatively even temp and that is where they age and store the wine. I have heard it said every year is a vintage year in Napa Valley.

#24 Randall Nix,

Here is another earlier article about the possible increase in volcanic activity in Chile, from the same source as the report of excavations in India.

"An analysis of records in southern Chile has shown that up to four times as many volcanic eruptions occur during the year following very large earthquakes than in other years. This âvolcanic surgeâ can affect volcanoes up to at least 500 km away from an earthquakeâs epicentre.

A report of the work will be published in the journal Earth and Planetary Science Letters."

Perry I know I posted and passerby posted it a couple of weeks ago but thanks. It will be interesting to see what happens in that area;)