[meteorite-list] Dinosaurs were Not wiped out by a global firestorm??
From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Thu, 22 Jan 2015 17:51:37 -0600 Message-ID: <388548.72397.bm_at_smtp120.sbc.mail.gq1.yahoo.com> List, Somehow I doubt a laboratory barbeque is a good test of a global hypothesis. I'm sure if I could tinker with their fire-starter aparatus I could get it to ignite a mass of live branches just fine. I do it in my back yard with a butane pocket lighter every fall. I bet the experiment was fun, though. But the soot argument goes back a way. The lead author of the cited study, Claire Belcher, published several earlier papers suggesting that the soot was all transported from the impact site rather than being formed locally from fire in the sky frying the planet. This article gives a good review of both sides of the issue: http://www.geotimes.org/aug08/article.html?id=nn_carbon.html First, worth bearing in mind is that EVERY suficiently large impact has produced world-spanning soot layers: "A Systematic Study of the Correlations Between Meteorite Impacts and Soot Formation" http://www.researchgate.net/publication/28327177_A_Systematic_Study_of_the_C orrelations_Between_Meteorite_Impacts_and_Soot_Formation A really excellent study, worth the read. More (and recent) studies: "CU study provides new evidence ancient asteroid caused global firestorm on Earth" http://www.colorado.edu/news/releases/2013/03/27/cu-study-provides-new-evide nce-ancient-asteroid-caused-global-firestorm#sthash.DvCOzUCZ.dpuf "The Survivors! New Theories About the Chicxulub Asteroid Impact 65 Million Years Ago": http://www.dailygalaxy.com/my_weblog/2013/07/the-survivors-new-theories-abou t-the-chicxulub-asteroid-impact-65-million-years-ago.html "The Rock That Changed The World": http://www.esi.utexas.edu/outreach/ols/lectures/ppts/54.pdf This next study pooh-pooh's the soot, but keeps the fire. Personally, I would rather have a little soot fall on me than be exposed to a red-hot 2700-degree sky... given the choice. "K-Pg extinction: Reevaluation of the heat-fire hypothesis" http://onlinelibrary.wiley.com/doi/10.1002/jgrg.20018/abstract They say, "However, global firestorms are consistent with both data and physical modeling." Worth noting is that massive impacts are not the only possible source of global wildfires. At oxygen concentrations of 24% or more (the present concentration is 20%), global wildfires will break out spontaneously. This level of oxygen concentration has been exceeded at various eras in the past: "Since the start of the Cambrian period, [the] atmospheric oxygen concentrations have fluctuated between 15% and a maximum of 35% of atmospheric volume towards the end of the Carboniferous period (about 300 million years ago)..." http://en.wikipedia.org/wiki/Geological_history_of_oxygen I can't help noting that a researcher in cold, wet Exeter doubts the fires and American researchers in our hot, dry South- west find them much easier to believe... Sterling Webb ------------------------------------------ -----Original Message----- From: Meteorite-list [mailto:meteorite-list-bounces at meteoritecentral.com] On Behalf Of Paul H. via Meteorite-list Sent: Thursday, January 22, 2015 10:39 AM To: meteorite-list at meteoritecentral.com Subject: [meteorite-list] Dinosaurs were Not wiped out by a global firestorm?? Dinosaurs were Not wiped out by a global firestorm Jonathan O'Callaghan, Daily Mail, January 22, 2015 http://www.dailymail.co.uk/sciencetech/article-2921547/Dinosaurs-NOT-wiped-g lobal-firestorm-Asteroid-impact-not-hot-ignite-nearby-plants-study-claims.ht ml Doubt cast on global firestorm generated by dino-killing asteroid (Pioneering new research has debunked the theory that the asteroid that is thought to have led to the extinction of dinosaurs also caused vast global firestorms that ravaged planet Earth.) University of Exeter. http://www.eurekalert.org/pub_releases/2015-01/uoe-dco011915.php Belcher, C. M., R. M. Hadden, G. Rein, J. V. Morgan, N. Artemieva, and T. Goldin, 2015, An experimental assessment of the ignition of forest fuels by the thermal pulse generated by the Cretaceous-Palaeogene impact at Chicxulub. Journal of the Geological Society, First published on January 22, 2015, doi:10.1144/jgs2014-082 http://jgs.geoscienceworld.org/content/early/2015/01/19/jgs2014-082.abstract http://jgs.geoscienceworld.org/content/early/2015/01/19/jgs2014-082.full.pdf +html Yours, Paul H. ______________________________________________ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list at meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list Received on Thu 22 Jan 2015 06:51:37 PM PST |
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