Comet Theory Boosted

[Minimalist]

http://www.eurekalert.org/pub_releases/ ... 092407.php

What caused the extinction of mammoths and the decline of Stone Age people about 13,000 years ago remains hotly debated. Overhunting by Paleoindians, climate change and disease lead the list of probable causes. But an idea once considered a little out there is now hitting closer to home.

A team of international researchers, including two Northern Arizona University geologists, reports evidence that a comet or low-density object barreling toward Earth exploded in the upper atmosphere and triggered a devastating swath of destruction that wiped out most of the large animals, their habitat and humans of that period.

“The detonation either fried them or compressed them because of the shock wave,” said Ted Bunch, NAU adjunct professor of geology and former NASA researcher who specializes in impact craters. “It was a mini nuclear winter.”

[Digit]

“It was a mini nuclear winter.”

Hang on a minute, wasn't it supposed to have gone on for years?

[Beagle]

NOTE: The work by an international team of researchers that points to a comet or low-density asteroid as the cause of the massive Ice Age extinctions has attracted widespread attention. The National Geographic Channel, which was on campus in May to film Northern Arizona University’s Ted Bunch and Jim Wittke, will air a documentary on the research on Sunday, Oct. 7, at 10 p.m. EST. Discover magazine cited Bunch in an article on “The Great American Extinction” that appeared in the August issue.

Min - maybe a Pando event?

[Beagle]

“It was a mini nuclear winter.”

Hang on a minute, wasn't it supposed to have gone on for years?

It did Digit. It brought on the Younger Dryas event. The full article explains better.

[Digit]

Quite Beag, was he trying to be a master of understatement or something?

[Cognito]

“It was a mini nuclear winter.”

Hang on a minute, wasn't it supposed to have gone on for years?

If (and this is a BIG IF) the Younger Dryas was created by comet impact with the resultant melting of the Laurantide Sheet, it would take hundreds and hundreds of years to get the earth's climate back to normal. If the event occurred as advertised, then the Northern Hemisphere temperature drops would have taken somewhat less than three years and been more extreme than let on in the article.

The Younger Dryas was a severe climactic flip-flop that put the earth back into a full ice age for 1300 years. I am not certain what caused it, but it was a complete disaster for cultures emerging from the LGM deep freeze while a collective "Aw Shit!" was heard throughout the land.

[Beagle]

If (and this is a BIG IF)

Hi Cogs, have you heard some arguments against the comet theory or are you having doubts about now? It has seemed to me that every couple of weeks a new scientist or two comes out in favor of it (as in this article that Min posted).

If you have any contrary info please let me know.

[Minimalist]

NOTE: The work by an international team of researchers that points to a comet or low-density asteroid as the cause of the massive Ice Age extinctions has attracted widespread attention. The National Geographic Channel, which was on campus in May to film Northern Arizona University’s Ted Bunch and Jim Wittke, will air a documentary on the research on Sunday, Oct. 7, at 10 p.m. EST. Discover magazine cited Bunch in an article on “The Great American Extinction” that appeared in the August issue.

Min - maybe a Pando event?

Shit. I'll be in Turkey.

[Beagle]

Whoops, we posted at the same time.

Anyway, I guess I'll have to subscribe to the NG channel. Or wait for Nova to carry it later this year.

[Cognito]

Hi Cogs, have you heard some arguments against the comet theory or are you having doubts about now? It has seemed to me that every couple of weeks a new scientist or two comes out in favor of it (as in this article that Min posted).

Beags, I don't believe all the information is in yet and I'll take this opportunity to remain skeptical until it is. First of all, I don't believe the dates given are as tight as everyone would like them to be (I'll need to re-review Mike Waters' data again on Clovis). Second, the article mentions the comet's affect on two continents -- North America is one of them, which is the other? If it's Europe, I'm not reading anything about similar finds on Europe yet. Either that or I've missed something. Third ... well, let's handle the first two and move on, OK?

[Digit]

You may mean SA Cog, which cooled before NA, odd eh?

[Beagle]

No one has found a giant crater in the Earth that could attest to such a cataclysmic impact 13,000 years ago, but the research team offers evidence of a comet, two and a half to three miles in diameter, that detonated 30 to 60 miles above the earth, triggering a massive shockwave, firestorms and a subsequent drastic cooling effect across most of North America and northern Europe.

Here it mentions Northern Europe. It doesn't say if "black mat" evidence is in Europe or not. I've thought that there may be a connection to the Siberian mammoth extinction.

It's always wise and prudent to wait for all the evidence, I agree. In the meantime, I'm pretty positive in thinking that there was a cosmic event over North America at this time.

Thanks Cogs.

[Forum Monk]

So I am wondering, if a comet exploded in the western hemisphere 13kya which blasted the megafauna out of existence or eventually did, there should be a sizeable gap in the archaelogical record as certainly man would have been brought to extinction as well, in the western hemisphere. A 1300 - 1500 year gap is noticable, is it not? Unless of course, the surviving asians rushed in to fill the gap.

[Beagle]

So I am wondering, if a comet exploded in the western hemisphere 13kya which blasted the megafauna out of existence or eventually did, there should be a sizeable gap in the archaelogical record as certainly man would have been brought to extinction as well, in the western hemisphere. A 1300 - 1500 year gap is noticable, is it not? Unless of course, the surviving asians rushed in to fill the gap.

Actually, I was told that there is an 800 - 1500 yr. gap between Clovis and later paleoindian cultures. This absence of human activity was very noticeable at the Topper site.

But my understanding is that many faunal species might have been in sheltered areas. For instance, there may have been some humans that were in caves or under cliff overhangs. The mammoth and other very large animals would have had little chance.

Without seeming to be stretching things, I think it's interesting that the ancient mesoamericans have a creation myth that has the first man emerging from a cave. And caves remained sacred to them. (ok, it's a stretch)

[Forum Monk]

I didn't mean to suggest the extinctions were caused by the blast, as devastating as it may have been. The Younger Dryas would have been a major stress on species survival and rendered NA virtually uninhabitable. Strange, though, that areas of the southern hemisphere were believed to have been cooling down long before the YD. The north american reversal may have been preceeded and triggered by the southern reversal. Look at the huge effect El Nino/La Nina has in the modern era on our weather.

I am not denying the space blast theory. Just thinking out loud.