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Fraser
2004-Aug-30, 05:55 PM
SUMMARY: When a huge asteroid slammed into the Earth 65 million years ago, it began a catastrophic chain of events that caused the extinction of the dinosaurs, and 75% of the species on Earth. One devastating aspect of the event was when hot debris rained down, starting enormous wildfires across the entire planet. Scientists from the Southwest Research Institute have come up with a model that calculates how large an impact had to be to cause massive fires. A crater 85 km (52 miles) across probably caused continent-wide fires, and a crater 135 km (83 miles) across could ignite fires around the whole world.

What do you think about this story? Post your comments below.

StarLab
2004-Aug-30, 06:39 PM
"The Chicxulub impact event may have been the only known impact event to have caused wildfires around the globe," Kring noted. "The Manicouagan (Canada) and Popigai (Russia) impact events, however, may have caused continental-scale fires. The Manicouagan impact occurred in the late Triassic, and the Popigai impact event occurred in the late Eocene, but neither has been firmly linked yet to the mass extinction events that occurred at those times."
Could the Permian extinction also have involved global fires?

Also, in the Jurassic Park: the Lost World (the book), Ian Malcolm reveals a theory that behavior led to the extinction of the dinosaurs, and claims the dinosaurs died out somewhat after the Chixculub impact. Is it possible the Eocene extinction could have involved the dinosaurs, rather than the Cretaceous one?

Al Pickrel
2004-Aug-30, 07:16 PM
I few months ago Universe Today published a link to a java program that allowed me to enter various size, angle and material data of a a potential asteroid and then the program would calulate the effects of such an impact. I had a lot of fun with it, but now I can't find it. I am sure it is in your archives someplace.

I don't know why this sytem is treating me as an unregistered user. I have never had this problem before. I am insulted ;-).

om@umr.edu
2004-Aug-30, 07:37 PM
An interesting story, Fraser.

Enormous wildfires can be triggered by many events, including nuclear warfare. Linus Pauling used to tell a story to illustrate this point:

During the Cuban missle crisis many newspapers in this country carried a series of articles entitled something like, "How To Be Safe in A Nuclear War" written by a Nobel Laurate of C-14 fame.

The stories explained how a shovel, a few "gunny" sacks, and old railroad ties could be used to construct a fall-out shelter that would save us.

1. Dig a hole in the ground with the shovel.

2. Put the dirt in the gunny sacks.

3. Lay the old railroad ties across the hole.

4. Stack the dirt-filled sacks on top of the railroad ties.

5. In the event of nuclear attack, crawl in the hole with a few cans of water and be shielded on all sides from radioactive fallout by dirt.

Linus Pauling claimed that the author of these popular newspaper articles build a demonstration model of this cheap fallout shelter near his home in Beverly Hills, CA. There was a forest fire, which caught the old railroad ties on fire, dumping the gunny sack of dirt into the cavity below.

Fortunately, the Nobel Laurate was not inside the fallout shelter at the time.

With kind regards,

Oliver
http://www.umr.edu/~om

lswinford
2004-Aug-30, 07:48 PM
Don't forget Princeton's Gerta Keller (http://www.cnn.com/2004/TECH/science/03/02/coolsc.dinosaurs.extinction/index.html) that suggested, with a bit of approval from New York's American Museum of Natural History paleontology chairman Mark Norell, that not all became extinct from the asteroid collision.

(As for the 'fallout shelter' I recall a US GPO booklet on 'surviving a nuclear attack' that gave illustration of using a door as a 'lean-to' on the side of a house. The door was then covered with dirt, from underneath the door's 'shelter' to at least half-a-foot deep. It was obvious, such as the open sides, that this was not a long-term solution, but something to do during the supposed ten to twenty minutes between when notice was supposed to be given and when 'the bombs began bursting in air'. I thought it was a diversion and an opportunity to dig one's own grave, since the person would be hunkered down in that door and dirt covered hole, since there may not be many available or interested to do so after the attacks. Fairly, most instructions used basements and storm shelters, however, which were reasonable precautions. Unfairly, I have a suspicion that we might not get much, if any, notice with any future nuclear exchanges.)

Guest
2004-Aug-30, 10:24 PM
Taken with a grain of salt, love it when somebody theorizes and everyone accepts the theory as fact, untill the theory is proven wrong, and then hearing how everyone knew something was wrong with that theory!

JoAnn and Bob Henstra

mark mclellan
2004-Aug-31, 07:20 AM
The fire facts that go with any asteroid impact probably have a more long term effect to the planets species than immediate, you can probably walk away from the burning area but you wouldnt be able to walk away from the climatic changes caused by fires of a global nature. I have always wondered why most of (not all) the mass extinctions appear to wipe out the larger of the planets creatures. I think that its because most of the massive asteroids will have hit the oceans thus creating waves that would impact the land with such devastation that they would batter/drown anything and everything at ground level to maybe a couple of hundred feet above, but not having a massive impact on flying creatures, ocean/sea creatures or the small mammal type creatures that live and burrow a couple feet underground. Just some thoughts. Ocean strikes would also put out fires or water log enough to stop the entire planet from burning.

lswinford
2004-Aug-31, 07:05 PM
Way to go Mark! And with so much of the world covered in water, the odds are great you are right. LOL!

In that CNN piece, they were guessing that the following extinctions took place some several hundred thousand years later, which isn't exactly a single-event's sudden jolt.

moonglow
2004-Sep-01, 04:25 AM
We suppose its alright to speculate about the results of natural disasters.

"Supposing is good, but finding out is better" (Mark Twain)

When science uses the established scientific laws they seem to do better in discovery.

I.E., Our planet has life and orbits a yellow star.
Conclusion, check the nearest yellow stars for planets and then life. :P

Planets are currently discovered using known laws such as Newtons Law of Gravity, and Keplers Laws of motion. Non have been discovered using theories. :D

Theories are never involved in discovery, because theories are not laws, theories always arse fter discovery and serve no purpose but to get some scientist published, publish or perish is the phrase most commenly used. Science can only say so much about laws, but science can say anything it wants about theory. The same with natural disasters, unless we have experienced chaos such as discribed above, speculation rules! :unsure:

Frazier, how about a spell check, please!