Talk:Permian-Triassic extinction event

From Academic Kids

Contents

1 Miscellaneous 2 See Also 3 Supernova evidence 4 The Bedout crater

Miscellaneous

I've just been watching a fascinating documentary about the permian extinction on TV, according to this fossil evidence recently (1999) discovered in Greenland shows that the extinction took place over some 100,000 years, and happened iin 3 distinct phases- the Siberian traps caused global warming of some 5 degrees which accounted for much extinction on land- this also caused the seas to warm, in turn killing much marine life, and at the same time releasing vast quantities of methane from the seabed (and presumably from the huge amounts of rotting matter from all the dead sea life), which in turn warmed the global temp. by another 5 degrees, causing a second mass land extinction. This theory was put together by a guy from Leeds university in England, and apparently has the most credibility at the present time (tho i'm only a lay pwerson and am just basing this on the program I've just seen) quercus robur

Well, go ahead and clean up the above and insert it into the article! :) --Dante Alighieri 23:31 Dec 5, 2002 (UTC)

urg- bit tired at the moment- one for the 'to do' list- as you say, needs quite a bit of cleaning up to look presentable... I'm better at punk rock and one hit wonders minutiea when in this sort of frame of mind ;-), quercus robur

The show you watched seems to be on target (be careful about using the tele as source material in general though - programs often give the impression that crakpot ideas are well-accepted theories). --mav

This was BBC 2's 'Horizon' program (in the UK), which is a fairly respectable source, been going donkeys years, puts much current scientific thinking into laymans terms a dork like me can understand... This particular program was very well presented and gave attention to several other theories, plus reasons why they were less likely than this new theory... Cheers quercus robur

Great article! Just one quibble: the article states that "85% of all marine species and 70% of all terrestrial species went extinct." I don't see how this adds up to the claim, in Extinction event, that 95% of all species died during the Permian event. Could someone explain?

Oh, and one more thing: the article states that "release of debris and carbon dioxide into the atmosphere reduces the productivity of life and causes both global warming and ozone depletion." If I'm not mistaken, release of ash/debris (similarly with volcanic eruptions) actually leads to global cooling. -- CYD

The bebris cause short to medium term cooling but the CO2 causes warming in the longer term. --mav

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I went to the BBC2 Horizons archive and tried to distill what I understood about methand hydrate gasification, and entered it. Sharpen it up! but add more references and external links to what you find, please! Wetman 06:04, 25 Nov 2003 (UTC)

See Also

A well-intentioned editor has crosslinked, via "See Also" sections, 3 articles among the 6 event-articles that extinction event links. Most of these are redundant to identical links within the running text (the preferred location for links; see Wikipedia:Manual of Style#See also and Related topics within). The remaining two either are redundant to the extinction event links elsewhere in the respective articles these (redunadant) links appear in, or deserve an explanation (within the running text) of their connection. --Jerzy(t) 17:20, 2004 May 7 (UTC)

Supernova evidence

While some sedimentary rock samples contain what may be records of short-term ozone destruction (large amounts of NOx gases and C14), this theory has little other evidence either for or against it.

How can those rocks contain C-14? It must have decayed a long time ago. Is there some method to determine how much C-14 was in the rock - maybe N-14 atoms if they stay where they were produced? 193.171.121.30 04:57, 21 Feb 2005 (UTC)

Yeah that is strange. All the carbon would be gone and you wouldn't imagine you could really test for nitrogen isotopes cause the atmosphere is swimming in it. There is a big C-13 excursion at that time, but that is usually interpreted as merely resulting from the disruption to the biosphere. Dragons flight 05:39, Feb 21, 2005 (UTC)

Agreed and removed sentence from article. Some sed. rock samples and what may be - weasel phrases. If someone has a reference to back it up, they can re-insert. -Vsmith 05:54, 21 Feb 2005 (UTC)

On a side note, ozone destruction shouldn't significantly reduce C-14 creation because the ozone layer has not much influence on the cosmic radiation. 193.171.121.30 11:46, 23 Feb 2005 (UTC)

No, the huge pulse of radiation and cosmic rays from the supernova itself would be expected to create an enormous overabundance of C-14 and nitrous oxides. The NOx subsequently depletes the ozone layer. That's the theory anyway. But as far as I am aware there is little evidence of it every having occured. Dragons flight 01:23, Feb 24, 2005 (UTC)

The Bedout crater

I removed this text, because the link seems to be dead and the substituted information and cited sources seem more informative and current.: "One group examining Bedout drill cores has pointed to certain unusual geologic features as evidence for an impact origin of this site (see [1] (http://128.102.38.40/impact/news_detail.cfm?ID=142)). However, this remains disputed with other experts favoring large scale volcanism as responsible for the Bedout structure." I added material on the Bedout structure, as I had missed the importance of the passive link before, and I've read this several times. Please vet my changes. --Wetman 16:07, 27 May 2005 (UTC)

Obviously, we will also want to add some mention of all the scientists that think Becker et al.'s work is full of holes. I may try to do this in few days, if no one gets to it first. Dragons flight 18:19, May 27, 2005 (UTC)

That would restore the full picture. Thanks. --Wetman 21:01, 27 May 2005 (UTC)