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Hundreds of earthquakes have hit Yellowstone National Park, raising fears of a more powerful volcanic eruption.
The earthquake swarm, the biggest in more than 20 years, is being closely monitored by scientists and emergency authorities.
The series of small quakes included three last Friday which measured stronger than magnitude 3.0. The strongest since this latest swarm of quakes began on December 27 was 3.9.
No damage has yet been reported but scientists say this level of activity - there have been more than 500 tremors in the last week - is highly unusual.
"The earthquake sequence is the most intense in this area for some years," said the Yellowstone Volcano Observatory. Some of the larger earthquakes have been felt by park employees and guests, according to the observatory.
The swarm is occurring beneath the northern part of Yellowstone Lake in the park. Yellowstone sits on the caldera of an ancient supervolcano and continuing geothermal activity can be seen in the picturesque geysers and steam holes, such as Old Faithful.
About 1,000 to 2,000 tremors a year have been recorded since 2004. The most devastating earthquake in recent history in the Yellowstone region occurred on August 17, 1959, when a magnitude 7.1 earthquake hit.
It was centered near Hebgen Lake, Montana and it caused landslides that killed 28 people and caused more than $11 million in damage.
Geysers in Yellowstone National park changed eruption times, and new ones began to erupt. On June 30, 1975, a magnitude 6.4 tremor hit the park.
Professor Robert B. Smith, a geophysicist at the University of Utah and one of the leading experts on earthquake and volcanic activity at Yellowstone, said that the swarm was significant.
"It's not business as usual," he said. "This is a large earthquake swarm, and we've recorded several hundred. We are paying careful attention. This is an important sequence."
The last full-scale explosion of the Yellowstone Supervolcano, the Lava Creek eruption which happened approximately 640,000 years ago, ejected about 240 cubic miles of rock and dust into the sky.
Geologists have been closely monitoring the rise and fall of the Yellowstone Plateau as an indication of changes in magma chamber pressure.
The Yellowstone caldera floor has risen recently - almost 3in per year for the past three years - a rate more than three times greater than ever observed since such measurements began in 1923.
From mid-summer 2004 through to mid-summer 2008, the land surface within the caldera moved upwards as much as 8in at the White Lake GPS station. The last major earthquake swarm was in 1985 and lasted three months.
The observatory said similar swarms have occurred in the past without triggering steam explosions or volcanic activity. However, the observatory said there is some potential for explosions and that earthquakes may continue and increase in intensity.
Joe Moore, director of the Wyoming Office of Homeland Security, said his office is tracking the events at Yellowstone on a minute-by-minute basis. "It's being followed very closely," Mr Moore said.
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i majored in geology in 2000; specializing in earthquakes & volcanoes. My paper was on the "Not If--When" volcano eruption in Yellowstone Park. I find this is very interesting & plan to keep watching via internet. Hope to get to Yelowstone sometime this year.
Lynda, Deltona, USA
There is also a super volcano in New Zealand near Australia, It has also come to life to the point that we are keeping a close eye on it at this very moment, could they be that we have hit a cycle point in the Earths life?????
Peter Towle, North Rockhampton, Australia
Daniel from Phoenix, that was FUNNY! Someone rear ended me and totaled my car when I was on my last car payment. The History Channel has recently had some great shows on Light as well as volcanoes. No one knows the day or the time. All of these predictions are guesses.
Sherryll, modesto,
Oh well here we go....Have had a funny feeling about all of this for almost a year. Never watched earthequake reports or volcanos, but now I catch myself on the computer almost everyday looking at what is going on. I don't know why, just know that I do.
paula, aiken, usa
My little part is we are still not able to comprehend our insignificance on this earth and universes ebb and flow. Yellowstone, from the sulfur from below is going to blow and it wil be primordial in scope. And it will not take notice one whit of our reaction.
mark, ft myers, usa
E.L.E. is scheduled for December 21, 2012 according to all the shows on the History Channel this week. Funny. That is the same day my truck will be paid off. No worries. I'm sure Obama is on it.
Daniel, Phoenix Arizona, USA
Always be prepaerd for this or any other event people,you are on your own,i repeat,you are on your own,of course how would one be prepaerd for an E.L.E
L anderson, lawrencburg, USA
If the news from yellowstone is indeed being suppressed, it is probably to protect the value of the U. S. dollar.
Pete V. Utah
Peter C. Vander Meide, Cove Fort, Utah, usa
While an official from the Wyoming Department of Homeland Security is quoted in the article, I can't find any info about the quake swarm on their website. I find their silence disturbing.
Mary, Flint, USA
I guess we started early with the sky falling in 2009.
OK...
First off, there have been swarms detected in that area for decades. No supervolcano had erupted then. No supervolcano erupted in 1985. It's just as likely that no supervolcano is going to erupt this year either.
mackro, seattle, usa
why are the news media not talking about this.only a couple of minutes today and that was it.
Bonnie, tucson, usa
I don't know what is going on, but it is almost impossible to find any news about this in the U.S. However, if you're interested in Brittney Spears and others like her, and what is going on in Hollywood, then you can find plenty of that kind of news. Actually, it's hard to escape that kind of news.
Kate, Englewood, USA
i live about 170 miles away from yellowstone, and it is all over the local news and is being talked about left and right. it has been reported that the super volcano has moved into the red zone. meaning it could erupt at anytime. it is very worry-full to think about. if it erupts, i will die...
jordyn bason, sheridan WYOMING, u.s
It's not being reported in the US? Are you kidding? There have been almost 700 news articles about Yellowstone's earthquakes since Dec. 24. Coverage has been more than adequate.
Elle, Houston, USA
I've been following this since last week but the reports I've been seeing have all come across as though this was some sort of surprise or something. One even referred to tremors as unusual in the region. Anyway, I certainly hope it doesn't go anytime soon!
Phillip, Plano, USA
This is very disturbing why it is not even remotely being talked about on any u.s. news. I checked the website of USGS and there is no updates. Whats up with that????. All I can say is everyone needs to ask about this. Hopefully its just a natural disturbance. But it is strange, it is not mentioned.
ken s. , san diego, USA
i have seen no mention on any local or national news makes you wonder
rj bleimeyer, los angeles, usa
I bet the Europeans and the UN woiuld blame the U.S. for "destroying the world" if it blows. Be nice to know we won't have to listen to that much longer after and eruption.
Jake, Bozeman, USA
oh my god ! i just moved within the yellowstone ecosystem , from North Dakota ! although we would be toast in the western dakotas as well. now we will go that much quicker here in the Livingston Montana area, front row seat, Well, if it happens, I guess I will see you all on the other side !
Tamara, 1 hour north of yellowstone , USA
YELLOWSTONE IS THE MOST DANGEROUS VOLCANO IN THE WORLD. The government has no policy on telling the public anything. It has erupted within the last 640,000 yrs but they have been on a smaller scale. Swarms come and go but being prepared for the worst and praying for the best is always prudent.
Les, sacramento,
This link shows all the quakes and the period on which they occured in an animation.
http://quake.utah.edu/req2webdir/recenteqs/Anim/anim_yell.html
Nathan, Melbourne, Australia
Sad to think that the first I've heard of this is from an international paper. Interesting read and definitely something I"ll be keeping an eye on
Emmy, Las Cruces, NM, USA
It is something the whole world would have to worry about if a huge caldera forming event occurred. The midwest of the US is not just the breadbasket of the US, but of the world. Worldwide starvation would follow such an event. Good news is, such an event is highly unlikely.
Bryan, Madison, Wisconsin, USA
Funny a commentator from LA says he pities inhabitants near Yellow Stone.. Califonia being on a majot faultline expected to give way at any moment and all.
Dom, Bordeaux, France
Horizon said "It is little known that lying underneath Yellowstone Park - is one of the largest supervolcanoes in the world. Scientists have revealed that it has been on a regular eruption cycle of 600,000 years. The last eruption was 640,000 years ago... so the next is overdue."
V Glover, Penzance, UK
A good big eruption here would make the New Orleans disaster seem like a picnic......
David Ashton, Bathurst , A
I think there will be a new crater within 25 years. It's a long way overdue and maybe it's just what the earth needs to finish this circle of the most stable times we have been living in.
Buck, Australia,
In 1959 we were in WY. My brother was afraid at Yellowstone, kept asking Dad if there were earthquakes there. Patience worn thin, Dad said "Yes--next week!" Well. " next week " we're home and the '59 earthquake hit. Want to know what's going on, just ask MY Dad!!!!!
Barb, Rolla, USA
The N American plate heads SW, so the magma chamber shifts NE under it plowing through the crust, so there have to be tiny quakes on the NE side of the caldera that we see now. This may be all there is to it. A chamber collapse would be preceded by quakes all over the area, not just one side.
Hermann Burchard, Stillwater , Oklahoma
If the Yellowstone volcano does blow, we won't have to worry about global warming - we'll be worrying about a new ice age!
Andrew, St. Ives, Cambridgeshire,
Does anyone know our governments policy on notifying the public ?
scott, Libertyville, USA
This is the caldera of an ancient volcano and if this erupts Hollywood terror becomes real
Phil de Buquet, Newport,
Just waiting for someone to try to say this is caused by "Global Warming." Well, if Yellowstone blows its top, I don't think AGW is going to be much of a concern anymore.
Scott, Durham, NC, USA
Just hope (and pray) that an eruption of a supervolcano isn´t on the way...
more in
www.bbc.co.uk/science/horizon/1999/supervolcanoes.shtml
Henrique, Lisbon, Porugal
The Supervolcano under Yellowstone National Park is so large that if it does blow the same as it did 640,000 years ago then it will seriously threaten the human race. The last time only about 2,000 humans survived, about 10% of the population.
Stuart Budd, Bristol, Bristol
I dont think you fully grasp this, if it goes up anyone west of the mississippi will not be here anymore, and the rest of the world will suffer for years after.
charles, london, uk
A BBC programme, Horizon, a serious science documentary stated that a "super volcano" was imminent at Yellowstone several years ago. The result of which would have global effects of a very serious nature.
V Glover, Penzance, UK
An earthquake swarm? Surely, an earthquake pride is correct. BTW Is 'bunch', the standard multipurpose American collective noun, no longer scientifically acceptable?
Derek, Taunton, UK
where is the most recent information from the USGS? Why hasn't the University of Utah updated it's website of press releases about what it's monitoring?
Liz, New York, USA
rose et al
i think that if Yellowstone goes boom it is a world wide problem because of all of the debris that will be ejected. it is also not clear what amount of ejectable material is in the magma chamber. i think that the rest of the world will not have its troubles to seek if it does go up.
Ron Oliver, edinburgh, scotland
I feel sorry for people living in the area of Yellowstone Park. If a disaster of some kind REALLY hit they won't get much help from the general public. Everybody is fed up with being constantly asked to give more money for every other man-made/natural 'disaster' on TV. I say help America first!
Rose, Alexandria, LA, USA
The scary thing is that there is NOTHING that we can do except to have plenty of survival items and Ca$h on hand. If Yellowstone blows with even a portion of its potential, it could disrupt the entire globe for several years.
Randy, Las Vegas, USA
I believe we all should keep a close eye on Yellowstone as well as the Middle east .Things are coming to a head.Stay Informed and ask others to as well
Karen Leah Holland, Boise, USA
The USGS has removed most of the current data regarding the quakes at Yellowstone(since I observed it yesterday)- There is not hardly a whisper being made in the media in the States regarding the danger going on at Yellowstone. I suppose this is being done in an effort to "protect" us.
Laura, Steamboat Springs, USA