From Indiana University
Scientists detect seismic signals from tornado
BLOOMINGTON, Ind. — An Indiana University geophysical experiment detected unusual seismic signals associated with tornadoes that struck regions across the Midwest last week — information that may have value for meteorologists studying the atmospheric activity that precedes tornado disasters.
The experiment by IU researchers involves deployment of more than 100 state-of-the-art digital seismographs in a broad swath of the U.S. midcontinent. One of the twisters that struck southeastern Missouri and southern Illinois on Feb. 29 passed through the seismic detection array.
“In examining the seismograms, we recorded unusual seismic signals on three of our stations in southern Illinois,” said Michael Hamburger, professor in the department of geological sciences at IU Bloomington and one of the researchers conducting the experiment.
“The seismograms show a strong, low-frequency pulse beginning around 4:45 a.m. on Feb. 29. Our preliminary interpretation, based on other seismic records of tornadoes, suggests that we were recording not the tornado itself, but a large atmospheric pressure transient related to the large thunderstorms that spawned the tornadoes.”
The seismographs that detected the pulse are near Harrisburg, Ill., a town of 9,000 where a pre-dawn twister caused extensive damage, killed six people and injured about 100 more.
IU researchers initially feared that some of the instruments might be damaged by the storm, setting back a National Science Foundation-funded project that included the investment of hundreds of thousands of dollars and months of effort. But when principal investigator Gary Pavlis, an IU professor of geological sciences, checked the digital recordings of the Illinois stations on Feb. 29, he found they were still alive and streaming data. As he checked further, he discovered the strange “tornado seismograms” that were recorded on seismographs near Harrisburg.
Hamburger said a seismic pressure gradient associated with the tornado produced a slow, minute tilting of the seismograph that lasted for several minutes. He said this sort of pressure-related signal may help scientists better understand atmospheric activity that takes place right before tornadoes touch down. The IU researchers are working with colleagues at the University of California San Diego to try to compare recordings with other tornado-related signals and to dig deeper into the analysis.
While seismographs have been known to detect seismic activity related to tornadoes, it is highly unusual to have state-of-the-art digital instruments recording information in such close proximity to a tornado, the researchers say.
The IU seismic experiment, dubbed “OIINK” for its geographic coverage in parts of the Ozarks, Illinois, Indiana and Kentucky, includes the positioning of 120 seismometers to study earthquakes and geological structure in a key area of North America. Installation of the instruments began last summer. They are recording thousands of earthquakes from the study area and around the world, as well as nearby mining and quarry explosions.
The $1.3 million, four-year undertaking is part of the NSF’s EarthScope program, which seeks to cover the entire U.S. with a grid of detection devices for the purpose of better understanding seismic activity and predicting earthquakes. Researchers liken EarthScope to “an upside-down telescope” that allows them to look into the Earth and gain a better understanding of seismic forces.
More details on the experiment are available at newsinfo.iu.edu/news/page/normal/18612.html.
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Interesting but what is the lead time between signal and tornado?
Sounds like something I might have read from the dutch media, but it does make sense when explained this inverted way.
Which came first?:
a) strong, low-frequency pulse
or
b) a large atmospheric pressure transient
Did they track the pre – tornado activity at high resolution weather maps? Unfiltered radar shows the early precipitates formations clearly.
And with any science, can that same phenomenon be found in the multiple other Tornado outbreaks around the US?
The atmosphere exerts a force of about 14 pounds per square inch over the entire earth’s surface, which comes to over a ton of pressure per sq ft, or 28 million tons per square mile. The fluctuation of just a very small part of that pressure would understandably show up as a seismic signal.
That’s it! That is what the loons have wanted to hear all along!
Co2 => change in atmosphere => more wind => seismic effects => Wild killer tornadoes which home in on old people, poor people and cute furry animals.
I hope you are proud of yourselves etc …
This is not surpising . Having been spit out of the top and bottom of big thunderstorms,
and had nearly been slammed into the earth by a downburst- in a 108,000 lb DC7,
Maybe there can be predictive study done here…
“An Indiana University geophysical experiment detected unusual seismic signals associated with tornadoes that struck regions across the Midwest last week — information that may have value for meteorologists studying the atmospheric activity that precedes tornado disasters.”
So they have recorded signals while the tornadoes struck? Wouldn’t it be an easier way to observe tornadoes by simply watching them? Their detection doesn’t have predictive skill.
Look Hansen, real scientific work being done here. What a change!
Whateva. Mother nature is a b!tch.
I just want it to stop raining in Ohio.
Sure these instruments are not just ‘feeling’ the thunderstorm?
sheesh, as usual, more testing needed, please send money!
/sarc
DirkH says:
March 8, 2012 at 9:10 pm
__________________
I think you may have missed this part. ” He said this sort of pressure-related signal may help scientists better understand atmospheric activity that takes place right before tornadoes touch down.”
They are talking about the predictive value of the readings. ie the pressure drop in a geographical area just before the formation of a funnel can be sensed as a seismic signal.
Being located in tornado alley this is a pretty interesting piece for me.
…and IF they recorded a signal BEFORE the formation of actual tornadoes, the next obvious question would be, what’s the false positive rate, and can they say exactly where the tornado will hit. Because otherwise you just end up alarming the whole country for naught, and the warnings would immediately be ignored by everyone…
Not all tornadoes can be seen, many happen at night, and many are obscured by clouds, rain, hail, and dust etc. The inflow winds can substantially reduce local visibility even if the view path is clear. In much of the country local terrain, trees and buildings mask them from view until they are very close.
That is why radar is the primary method of monitoring tornado development over wide areas. Even a skillful trained spotter has great difficulty getting close to a tornado during critical stages of its development. That is why even though active research on tornado development has been going on since the 1950’s it was not until recently that anyone had succeeded in getting actual measurements of central pressure of a tornado and that was only a brief sample of a single event.
Observing tornadoes is much easier imagined than done.
It will be interesting to see how the seismic signal corresponds with other possible tornado indicators like infra-sound, and electrical signatures (electrical noise sometimes seen on television sets) that some have reported. If reliable this might be an excellent way to provide a second independent signature to validate suspected hook echo signatures of tornadoes on radar.
Larry
TG McCoy (Douglas DC) says:
March 8, 2012 at 9:04 pm
This is not surpising . Having been spit out of the top and bottom of big thunderstorms,
and had nearly been slammed into the earth by a downburst- in a 108,000 lb DC7,
Maybe there can be predictive study done here…
================================
Ummm, passenger or cargo flight ?, no radar ?, flight logs, no pilot would say “nearly slammed into the earth” without providing details of his recovery from his flight into a thunderstorm.
Please stop with your stories, they fool nobody.
As scientific instruments become more sensitive, through modern technology, it only needs the media to spread the hyped hysteria and modern mankind [the Green part] screams “Save our Planet!” or similar.
I blame ’24 hour Breaking News’ and the 100% safety/compensation mindset.
The best part is that it raises more questions than it answers. More funding!
These instruments are a tad sensitive and a local backwoods farmer removing the odd tree stump or three with dynamite may cause a state wide panic.
I agree; I am sure that for Venus it is the strong wind and heavy atmosphère that make this planet move
Going off like a tornado.. and making the earth move… hmmmm !!!
Jeff D says:
March 8, 2012 at 9:38 pm
DirkH says:
March 8, 2012 at 9:10 pm
__________________
I think you may have missed this part. ” He said this sort of pressure-related signal may help scientists better understand atmospheric activity that takes place right before tornadoes touch down.”
They are talking about the predictive value of the readings. ie the pressure drop in a geographical area just before the formation of a funnel can be sensed as a seismic signal.
Being located in tornado alley this is a pretty interesting piece for me.
Jeff, (if I am reading you correctly) is there enough lead in time with these things, as somebody suggested earlier? With all these things, it’s the amount of time the warning gives you that is crucial. Piers Corbyn seems to do rather well at predicting these events with some measure of skill, but even he can only regionalise on a large scale, not so easily on a local scale.
For me, if the “enemy” (no names) drops the bomb on the UK, we get at best four minutes warning (assuming rocket motors are still technically back in the 70s – unlikely unless an aging fleet), to do what precisely I am not entirely sure, pray to ones maker I suppose, damn all else one can do.
Equally, having advanced warning of an earthquake & its location, would only serve a purpose if it was say a couple of hours perhaps to evacuate the local population if possible in such a timeframe, otherwise it’s nothing more than a hellish torment to those who await impending disaster rather helplessly.
Brian Johnson uk says: (10:43 pm)
As scientific instruments become more sensitive, through modern technology, it only needs the media to spread the hyped hysteria and modern mankind [the Green part] screams “Save our Planet!” or similar.
The truth of that is to be found in no less an organ than the Daily Telegraph, in Geoffrey Lean’s blog. He observes that “Americans are starting to believe in climate change – but for the wrong reasons”:
Brian’s right, unfortunately. In the red corner, boring old scientific facts. In the blue corner, media celebrities and talking heads freely extemporise on the theme of manmade apocalypse. Which will catch the attention of a largely scientifically illiterate generation raised on multimedia? Come to that, what would Geoffrey Lean regard as “the right reasons” for believing in a falsehood, I wonder?
naturally Seth was the AP solar storm scare go-to man, and is still smug:
8 March: AP: Seth Borenstein: Solar storm not nearly as bad as could have been
By SETH BORENSTEIN, AP Science Writer – 1 hour ago
AP Business Writers Josh Freed and David Koenig contributed to this report
“We’ve seen a bit of an increase in mag (magnetic field) geo-activity, relative to what we saw earlier today,” said Norm Cohen, a senior space weather forecaster at the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center in Boulder, Colo…
Hours earlier, NASA solar physicist David Hathaway said that it appeared that the storm was over, based on a drop in a key magnetic reading…
It was never seen as a threat to people, just technology, and teased skywatchers with the prospect of colorful Northern Lights dipping further south.
But when the storm finally arrived around 6 a.m. EST Thursday, after traveling at 2.7 million mph, it was more a magnetic breeze than a gale…
http://www.google.com/hostednews/ap/article/ALeqM5gjNDef54eydBsxSmIlaGlojH4_Ow?docId=66dacc0267c442d786dd8fc0b0a873d1
I found the article quite interesting. I grew up in Indiana and attended IU. I still remember very well the night of Palm Sunday 1965, when a huge tornado outbreak did heavy damage across several states, including a town about 20 miles from where I was playing a church service. I have never stayed outside while a large tornado went overhead; I came close enough a year and a half ago here in Virginia when a tiny tornado (force 0, maybe 50 yards wide) came through our yard straight for the house at amazing speed. Watching from a front window, I couldn’t see a funnel cloud as such, just a whirling of debris that–yes–roared like a train, rattled against the house, and sped on. Tiny as it was, and low as were the wind speeds recorded for it, that tornado took out our largest and oldest tree, numerous very large branches from other trees, and our two largest bushes, including a rose 18 feet high and 32 feet across. Our neighbors across the street lost 8 large trees. The tornado was invisible until it hit, though I could hear the wind for a few seconds ahead of it.
It is possible that the scientists at IU are working from a prejudice toward CAGW; but even if so, it is also possible for new and useful things to be found out. Those pressure differences over large areas of land could very well provide data about changes under the ground surface, and I’d like to see what comes of the research.
I agree with ‘detection is not prediction’ above. Moreover, I would state (the obvious) that more measurement is not really more information either. (Beyond the trivial, that is.)
Sure, lots of what is seen as noise (in some types of measurement) is, in fact, made up of various random events doing their thing. But frankly, so what? Modern devices allow for ever more accurate measurement… … of what is, in the absence of sufficient cause-effect chains, still NOISE.
And if anyone thinks that statistics will ride to the rescue, given its complete divorce from the very concept of cause-effect, then they are deeply delusional. Had something similar yesterday in a meeting: a kind of madness that says that being able to measure more is somehow, magically, going to provide more INFORMATION. Of course, pointing this out was met with actual derision. Oh well, how was I to know that about the magic information bit that is attached to every signal, which clearly indicates its providence? And, of course, that every signal is a good hippie, and will stand clearly and uniquely differentiated from all the other hippies in its clan? Now, of course, I know better: I feel so deeply privileged to have been offered their correction (blinks tears from eyes).
Carol King would be proud.
http://www.youtube.com/watch?v=hoHuxpa4h48
wayne Job says: March 9, 2012 at 12:15 am
These instruments are a tad sensitive and a local backwoods farmer removing the odd tree stump or three with dynamite may cause a state wide panic.
I got to do some stumps with my dad as a boy, and there’s no way a seismograph will confuse that bang with a tornado. Light the fuse and run – does it get any better than that for a kid?
Pop kept a case of dynamite in the garage, but I think he threw it out when it started to sweat nitro.