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Earthquake Swarm at Yellowstone Supervolcano: Update
#1
Earthquake Swarm at Yellowstone Supervolcano: Update

http://www.usnews.com/blogs/capital-com ... date-.html

January 01, 2009 03:21 PM ET | James Pethokoukis |

So what is the latest with the ongoing earthquake swarm at the Yellowstone supervolcano caldera? Here is my just-completed email chat with Dr. Jacob Lowenstern of the U.S. Geological Survey, top scientist at the Yellowstone Volcano Observatory:

How would you characterize the recent level of seismic level? Terms like "swarm" are pretty alarming. How would place this level of activity in historical context to what the USGS/YVO have tracked before?

Lowenstern: Swarm refers to seismicity when there isn't a typical mainshock/aftershock sequence. In other words, the events are more similar in size. Swarms are very common at Yellowstone. This one is clearly bigger than normal, and is the largest since 1985. There were also some large swarms in the 1970s, but the seismic network was much cruder at that time and we weren't able to locate earthquakes as well.

Me: What might be the markers/indicators leading up to a major volcanic/seismic event? Do you think this is leading to a volcanic eruption of some sort? What does your gut tell you?

Lowenstern: The most likely "bad" things that could happen would be triggering of a larger earthquake or some sort of steam explosion set off beneath the lake. At this point, any kind of volcanic eruption is a long shot. That's why we haven't called for a volcano advisory. None of our other monitoring indicators show anything that is nearly so anomalous as the earthquakes. At this point, the most likely thing is that the swarm will continue, perhaps for weeks, and then will end without any other related activity.

Me: It is all or nothing? I mean, do we either get lots of small quakes leading to nothing vs. a supervolcano? Could there be grades of eruptions or events?

Lowenstern: There are LOTS of things in between. There have been 80 volcanic eruptions at Yellowstone since the last "supervolcano" eruption 640,000 years ago and hundreds of large steam explosions, some near the Lake. It is FAR more likely that we'd have a steam explosion or a small volcanic eruption than a supereruption. By the way, the last time a volcanic eruption occurred at Yellowstone was 70,000 years ago.

Me: So if we were leading up to a major event, what sorts of indicators might we expect to see? We haven't seen one in a long time.

Lowenstern: It is certainly an issue that the truly major events are not known on a human timescale. We've mostly witnessed the precursors to smaller eruptions. But before any kind of an eruption we'd expect a whole lot of change in the ground deformation as measured by GPS. Nothing has changed over the past week. We'd also expect larger earthquakes and a bunch of steam explosions before magma ever made it to the surface.


Me: What do you make of this comment from one of my readers: "It's not that there's lots of quakes or even that they're all within a mile or two of each other, the worrisome part is that they are all a few hundred yards apart from the surface down to 7.2 km defining a single chimney under high pressure causing radial fractures along its entire length. NPS says the magma chamber is as high as 8 km and if it is that close to the chimney reaching to 7.2 km, we may be in for an eruption. We need more info on this location and USGS should deploy the best seismic testing equipment in the Lake NOW."

Lowenstern: That is pretty fanciful. We've got a team of seismologists looking at the data. The swarm is over a 7 km length right now. None of the earthquakes are that big, so it may be that fluid pressure is moving around as rocks break and thus breaking new rocks. It's also important to realize that when your seismic stations are 10s of kms apart, you can't get good resolution on the depth. The best located earthquakes right now are shallower than 5 km, but greater than 3 kms. Most of the shallower reported depths are probably inaccurate.
"More than any other time in history, mankind faces a crossroads. One path leads to despair and utter hopelessness. The other, to total extinction. Let us pray we have the wisdom to choose correctly." ~ Woody Allen
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#2
http://www.earthmountainview.com/yellow ... wstone.htm


[Image: 96_00norris_L.jpg]
On a satellite I ride. Nothing down below can hide.
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#3
I have a pack of 5 dogs that live in the house with me. Pennywise

Though for the next 2 days the swarm's intensities and quantities did radically increase the pack had quieted back down to their normal nervous level.

They've been silent ever since and yes, they are all still alive. Close call for all of them last Saturday. Cats were all going apeshit too... They are now back to normal. <img src="{SMILIES_PATH}/cheers.gif" alt="Cheers" title="cheers" />
&quot;Confusion... first sign of a bad relationship-whether personal, societal or governmental&quot;
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#4
Quote:http://www.earthmountainview.com/yellows...wstone.htm


[Image: 96_00norris_L.jpg]


"Yellowstone ready to blow its cork!


got it! Lol!

[Image: YellowstoneFalloutAshBed.gif]

See where it says 'Mesa Falls ash bed' or whatever? We're about 15 miles away from Mesa Falls-a truly divine place.

About 60 miles as the eagle flies to the BIG DOTS... luckily there's this big thing called the CONTINENTAL DIVIDE between us and THAT.

What's been coming to me since the summer-often while mowing for hours and hours is 'IF we make it through the winter we will have a truly wonderful year'. I was thinking more about the weather v the 'popping of the cork'.

[video:1rwlmcxc]http://www.youtube.com/watch?v=RZMgLQuTluA[/video:1rwlmcxc]

<img src="{SMILIES_PATH}/applause.gif" alt="Applause" title="applause" />
&quot;Confusion... first sign of a bad relationship-whether personal, societal or governmental&quot;
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#5
http://www.straightdope.com/columns/rea ... ut-to-blow

Is Yellowstone Park sitting on a supervolcano that's about to blow?
January 2, 2009
Dear Cecil:

My friend Melanie loves to watch the Discovery Channel and share what she has watched with others. The problem is she can never get the story straight. Her latest tale is about Yellowstone Park sitting on top of a supervolcano that has been dormant for 6,000-ish years. She said the supervolcano is starting to show signs that point to its being active. Is there any truth to her tale?

— Tina

Cecil replies:

Cut Melanie some slack. Yeah, she screwed up some details: it’s been 600,000-ish years since Yellowstone's supervolcano has gone off full blast, not 6,000. She got the drift, though. Nobody's saying Yellowstone is going to blow in time to mess up your summer vacation plans. But it's a question of when, not if.

A supervolcano is one that explodes in (natch) supereruptions. Definitions vary, but usually we're talking a magnitude-eight (M8) eruption: one trillion metric tons of ash and other debris filling at least 100 cubic miles, typically upchucked over the course of about a week. Picture 1,000 Mount Saint Helenses, or 8 Tamboras. Besides causing regional devastation, supereruptions affect global climate. An Indonesian super 74,000 years ago kicked off a thousand-year drought that some contend caused a human population crash. One shudders to think what a similar blow would do now.

Yellowstone is both a supervolcano and a hotspot; the two don't always go together. A hotspot is the business end of what's known as a mantle plume, a stream of magma that rises hundreds of miles through a channel in the earth’s crust like the blob in a lava lamp. The Yellowstone plume head, 50 miles underground, is several hundred miles wide. Over time, the hot head melts the overlying crust, forming a smaller magma chamber. Yellowstone's magma chamber is just a few miles down and contains partially melted granite viscous enough to trap gas, allowing pressure to build. Periodically the pressure cracks the surface, explosively ejecting gas and disintegrated rock into the surface world. After about a tenth of the chamber's contents have erupted, pressure falls and the show's over. Reheat and repeat.

The Yellowstone hotspot has produced dozens of large eruptions over the past 16 million years, the last three within the Yellowstone volcanic field: two supers and one M7.4 lightweight that created 68 cubic miles of debris. They left overlapping giant calderas, or craters, each 10 to 50 miles wide. Since filled with lava and eroded, the calderas are inconspicuous and went unrecognized till the 1960s.

These three big eruptions were 640,000 years ago, 660,000 years earlier, and 800,000 years before that. See a pattern? Lurid reports suggest we're almost due, even overdue, but the pattern is illusory. Over the past 4.5 million years, large Yellowstone eruptions have come at irregular intervals of 300,000 to 2.4 million years. Furthermore, a series of smaller eruptions (relatively; one was Krakatoa-esque in magnitude) between 170,000 and 70,000 years ago ejected as much material as a super — perhaps enough to relieve the pressure, and danger, for a while.

And while you're waiting, why not enjoy some of our many fine geysers and hot springs? Yellowstone's thermal features obviously depend on the heat rising from the magma chamber, demonstrating that a supervolcano, when not wreaking global havoc, can be a lot of fun.

Yellowstone has been eruption-free for 70,000 years, neglecting occasional steam explosions. Two centers of resurgence within the last caldera, where the land heaves up and down several feet over the course of decades, bear watching, but there's no sign of imminent trouble. Volcanologists expect at least a few weeks of pre-eruption warning.

What's the chance of a supereruption anywhere in the world in the next 50 years? Estimates range from one chance in 1,000 to one in 10,000 — hardly cause for panic. When it does happen, though, a lot of people are going to be toast. A supereruption could kill tens of millions. Within 10 to 50 miles of the next Yellowstone vent, you'll be Pompeiiized beneath thousands of feet of hot ash. More than half the U.S. will experience ashfall, potentially fatal if inhaled. Ash and associated toxins could devegetate a third of the lower 48 (including some of the world's most productive farmland) for years or decades, leading to mass starvation. Grim, but so unlikely that the U.S. Geological Survey lists Yellowstone as only the 19th most dangerous American volcano. Pimples like Kilueha, Saint Helens, and Rainier top the list.

Yellowstone's cousins are worth watching. The last supereruption at the Long Valley caldera in eastern California was 760,000 years ago. Another would be devastating, but as at Yellowstone, major cities are distant enough to avoid being completely buried. Elsewhere, some giant calderas are frightfully close to urban areas. Lake Taal in the Philippines is only 40 miles from Manila. In Italy the rim of Campi Flegrei lies only five miles from central Naples. The last near-supereruption there came 35,000 years ago; a much smaller one killed 24 in 1538. Pizza napoletana on my next Italian tour? Sure. But make mine to go.

— Cecil Adams
&quot;More than any other time in history, mankind faces a crossroads. One path leads to despair and utter hopelessness. The other, to total extinction. Let us pray we have the wisdom to choose correctly.&quot; ~ Woody Allen
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#6
suddenly
activity on SOHO as well

comets passing in numbers

http://sohowww.nascom.nasa.gov/pickoftheweek/

Four comets in two days (December 26, 2008)
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#7
A week ago is when my pack went totally frantic hyper mode-that was when the swarm was going-it totally fried my nerves-since then? <img src="{SMILIES_PATH}/dunno.gif" alt="Dunno" title="dunno" /> energy wise... I've been feeling really good. No anxiety about it or the future.

I think as the last Mormon prophet said-"it will shake and it will quake, but it will not blow'... BYU-Idaho is almost directly across from Teton/Yellowstone. "they would not have created the University with all the kids in it if they thought Yellowstone was ever going to blow in our lifetimes" ... several Mormons have said that to me. The Prophet and never ending councils talk and pray about Yellowstone all the time.

PS-I'll fish around and see what they have to say about comets.
&quot;Confusion... first sign of a bad relationship-whether personal, societal or governmental&quot;
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#8
jeezuz, gardener......WHY??? did the Mormons ever decide in the first place that Utah was Beulah Land...surely one of the most godforsaken places on the planet...like The Gobi Desert???
I mean...are you saying it was because of Yellowstone???
You're talking about "Fire & Brimstone"!!!
Do Mormons believe Yellowstone is an entrance to Hell???
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#9
Quote:jeezuz, gardener......WHY??? did the Mormons ever decide in the first place that Utah was Beulah Land...surely one of the most godforsaken places on the planet...like The Gobi Desert???
DOH! I'm sure it was because nobody else wanted Utah, except rattlesnakes and gila monsters. Nobody there to interfere with deranged polygamous inbreeding schemes.
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#10
Quote:[quote author="Kalter Rauch"]jeezuz, gardener......WHY??? did the Mormons ever decide in the first place that Utah was Beulah Land...surely one of the most godforsaken places on the planet...like The Gobi Desert???
DOH! I'm sure it was because nobody else wanted Utah, except rattlesnakes and gila monsters. Nobody there to interfere with deranged polygamous inbreeding schemes.[/quote]


Nobody knows that Southern Idaho is 'that way' too. At least Western WY-lots of Nevada-a lot of Arizona and of course CA is heavily seeded with the Mormons. Who are all very prepared. 3 day 'go bags' should be going on special at the local markets anytime now-$20 and it is full of neat stuff.

But I'm not feeling anything shakey or energized at all and I've been in a lot of quakes and can tell the tiny ones are going via my houseful of dogs.
&quot;Confusion... first sign of a bad relationship-whether personal, societal or governmental&quot;
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