Shiva impact crater 500 km diameter--bolide estim. 40 km diam

[Martin]

Abstract of a paper delivered this month

http://gsa.confex.com/gsa/2009AM/finalprogram/abstract_160197.htm

 

Much larger event than Chicxulub, where the bolide is thought to have been only 8-10 km in diameter.

 

Physorg.com has this commentary:

http://www.physorg.com/news174827113.html

 

Apparently 3 things happened about the same time as the dino extinction some 65 million years ago:

 

1. Chicxulub---an estim 8-10 km bolide hits Earth off the coast of Yucatan in Gulf of Mexico.

 

2. Shiva---an estim 40 km bolide hits west of India off coast of Mumbai. Actually breaks off a chip of the tectonic plate, making a separate little Seychelle plate that drifts over towards Africa.

 

3. Series of massive volcanic eruptions forming the socalled Deccan Traps in India.

 

Maybe someone would like to give more detail on this? I don't know in what order these events occurred, or what the dates attributed to them signify. I've heard other theories about dino extinction.

[Arch2008]

Here’s the entire paper:

http://www.depts.ttu.edu/gesc/Fac_pages/Yoshinobu/Published_pdfs/Chatterjee%20et%20al.%202006.pdf

Great stuff, I guess (not a geology buff), and here is a diagram of the suspected impact crater:

http://www.sciencedaily.com/releases/2009/10/091015102246.htm

The sequence of events is supposedly Deccan volcanoes, Chicxulub impact and then about 300,000 years later, the Shiva impact. From his paper, it doesn’t seem as though it is conclusive that the structure is in fact an impact crater. I think that Chatterjee has been working on this since 1996 and hopes to go there and take some geological samples. I knew that the Chicxulub impact theory was in trouble. We’ll see.

Maybe the dinosaurs just said, “So long, and thanks for all the fish.”

[Moontanman]

An intelligent race of dinosaurs was the deciding factor in the total extinction of the dinosaurs. Much like what we're doing now, they had disrupted the ecology and the impacts and lava eruptions just made it more difficult for any dinosaurs to recover!

 

http://web.ukonline.co.uk/michael.magee/awwls/00/wls143.html

 

I know, I know, it's just too good to not at least mention>

[CaptainPanic]

So far there is no suggestion that the two comets (Chicxulub and Shiva) were related. But earth really doesn't get hit that often by large comets, so it would be extremely unfortunate if it got hit twice in a relatively short period.

 

The Shoemaker-Levy comet contained 21 fragments that all hit Jupiter. Could it not be that earth got hit twice by the same comet?

Jupiter got hit on the same latitude, but spread out widely on its southern hemisphere. The fact that Chicxulub and Shiva are on the other side of the world, but (nearly) on the same latitude (just like the Shoemaker-Levy fragments) only seems to agree with my little theory here.

 

Soil samples should be able to tell if the two are of the same origin perhaps.

Or perhaps we can find a third crater from the same era and on the same latitude? Somewhere in the Sahara perhaps?

 

 

p.s. Moontanman, your post is totally off topic, but would be a nice thread in itself. Perhaps the dino's cremated their dead, and that would be a good reason why we don't find fossils.

[Moontanman]

So far there is no suggestion that the two comets (Chicxulub and Shiva) were related. But earth really doesn't get hit that often by large comets, so it would be extremely unfortunate if it got hit twice in a relatively short period.

 

The Shoemaker-Levy comet contained 21 fragments that all hit Jupiter. Could it not be that earth got hit twice by the same comet?

Jupiter got hit on the same latitude, but spread out widely on its southern hemisphere. The fact that Chicxulub and Shiva are on the other side of the world, but (nearly) on the same latitude (just like the Shoemaker-Levy fragments) only seems to agree with my little theory here.

 

Soil samples should be able to tell if the two are of the same origin perhaps.

Or perhaps we can find a third crater from the same era and on the same latitude? Somewhere in the Sahara perhaps?

 

I've often wondered if the Cretaceous Tertiary boundary might have been marked by more than one impact. It always seemed unlikely to me that the Chicxulub impact event could have done in the entire planet but there is evidence on the moon that craters are sometimes caused by multiple impact events in the from of strings of craters and Shoemaker-Levy gave us some evidence of a comet breaking up after a close encounter and coming back to cause a multiple impact event. Such an event, even if it was several small impactors, would be devastating to the planets ecology, far more so than a large single impact event.

 

 

p.s. Moontanman, your post is totally off topic, but would be a nice thread in itself. Perhaps the dino's cremated their dead, and that would be a good reason why we don't find fossils.

 

I know, just me being a smart ass but in the pseudoscience forum it might be cool.

[Airbrush]

Cool info about the Shiva Impact. Thanks for sharing. Why have I never heard of that? It's certainly never been on the History Channel or the popular media.

[Widdekind]

According to the National Geographic Channel documentary Naked Science — Incinerator Earth (TV), as well as the History Channel documentary Jurassic Fight Club — Armageddon (DVD), chemical analysis of the Iridium layer, deposited by the Chicxulub impactor, strongly suggest that said impactor, was an asteroid, from the Main Belt, from the Asteroid Family known as Baptistina. Another large fragment, from this family, roughly 3 km across, created the Tycho Crater on the Moon, around 110 million years ago.