If an asteroid like this one, depicted in an artist's drawing, hit Earth's oceans, it could generate huge waves that would move more slowly than previously thought, but in the end, cause more damage.
Posted on 06/09/2002 7:18:17 PM PDT by vannrox
If an asteroid like this one, depicted in an artist's drawing, hit Earth's oceans, it could generate huge waves that would move more slowly than previously thought, but in the end, cause more damage.
In other words, if Earth gets walloped by a sizable chunk of cosmic debris, there's more time to run from the wave, but a much wider potential destruction zone, say researchers at Los Alamos National Laboratory, where the simulations were created.
The results of the study were presented June 5 at the American Astronomical Society meeting in Albuquerque, N.M. "The previous models were wrong," said Jim Danneskiold, a Los Alamos spokesperson for the team that worked out what is, to date, the most meticulous look at how air, water and the asteroids themselves behave when they smash into the oceans at 45,0000 miles per hour.
Computer scientists Galen Gisler and Bob Weaver used Los Alamos' Blue Mountain supercomputer and Lawrence Livermore National Laboratory's ASCI White supercomputer to run the simulations.
After three weeks of computing — the equivalent of more than million hours of individual processor time — they were able to work out the fine details of ocean impacts ranging from a quarter kilometer to a full kilometer in diameter. Their imaginary asteroids also ranged in density from heavy iron to lighter-weight rocks.
"One kilometer is about the threshold for global effects," said asteroid researcher Daniel Durda of the Southwest Research Institute in Boulder, Colo.
The model showed that a one kilometer iron asteroid strikes with the power of 1.5 trillion tons of TNT and produces a spout of water more than twelve miles high, said Gisler.
The simulation also confirmed what was shown in the movie Deep Impact: a big asteroid can produce tsunamis large enough to inundate huge areas. There's even evidence in the Yucatan that the dino killer asteroid that struck there 65 million years ago caused tsunamis that washed over large areas of land, Durda said.
But the real concern isn't just the big impacts, said Durda. Even a moderate to small chunk of rock from space could cause a lot of trouble when it hits the oceans, he pointed out.
For instance, on land, a relatively small, 30 to 50-meter-wide asteroid would create quite a crater and a blast what would cause local damage. The same event in the sea, however, would cause weaves that would scour a much larger area, Durda said.
"We know that the timescale of impacts (makes them) common enough that it warrants our attention," said Durda.
I don't know what to do with this kind of information. Probably nothing.
Bazillions of people live in Southern California although the next 8.0 earthquake is a little overdue.
Now I'm a little dubious of their calculations. An extra zero here and a zero there could throw off their predictive model by a considerable degree.
Tell me about global warming again...
I'd rather live here (S. calif) than Seattle. They are overdue for a big one. Every 300 years or so. And Mount Rainier could blow simultaneously. The last big quake they had was ~350 years ago (dated from geological records).
I've seen magnitude estimates of 8.5-9.5. This would seriously damage Bill Gates' property values.
--Boris
Seriously, though, the Pacific Plate keeps turning and we can expect techtonic and volcanic activity at any time anywhere along the Pacific Coast.
Heck, just for fun, I'll post the current earthquake map for California.
It was dated from records of aa giant tsunami in Japan as 1699 and caused great sinking and upheavels all along the NorthWesr coast. Indian legends abound about it. Core samples taken here in Humboldt Bay (Eureka) and Crescent City show sediment almost 2 feet thick. As a comparison the Crescent City Tsunami in 1961 that killed several people and did millions in damage left sediment 3 inches thick. This event was caused by the great Anchorage quake .
Oh, the bad ol earthquake is going to get us all. LOL! Nice try Dog.
A bad day in California, is better than a good day in Texas. Bet your looking forward to that Texas summer, of 100 plus degrees, with humidity to match. Hehehe he...
But I don't think the thread was about comparing weather.
But I don't think the thread was about comparing weather.
Oh, It thought it was about earthquakes. (Sarcasm)
Why are you dubious?
A quick check on the interent brings up a site which declares that:
There are many different speeds of asteroids. The average speed of an asteroid is 25km/second.
25km/second equals 56,000 mph, or nearly the same speed as they used for the model.
If you have a better number for the speed of asteroids, please share your expertise with us.
Oddly, the error seems to either have been the poster's fault, or the editors caught it and changed it in the linked article.
An abstract of the actual paper states that the velocity used for the models was 20 km/s.
Simulations of asteroid impacts on water
My post to you was a reaction to the sometimes kneejerk skepticism of science that I have encountered here. Obviously I picked the wrong target. You were quite right to draw attention to the error in the article as posted.
This reminds me of the time I first used a university's mainframe computer to analyze data from a unusually complicated experiment. This was back in the days when punch cards were still vogue. After reading through reams and reams of computer print-out the data summary conluded with "meen" and standard deviation. Needles to say, I chucked the whole thing.
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