Posted on 09/15/2003 8:48:14 PM PDT by UnklGene
September 15, 2003
Could an enormous volcanic eruption have killed the dinosaurs?
Cardiff University -- The extinction of the dinosaurs -– thought to be caused by an asteroid impact some 65 million years ago –- was more likely to have been caused by a 'mantle plume' -– a huge volcanic eruption from deep within the earth's mantle, the region between the crust and the core of the earth.
This theory, already supported by a significant body of geologists and palaeontologists, is strengthened by new evidence to be presented at an international conference at Cardiff University on 11-12 September.
Research by an American earth scientist, Professor Gerta Keller and her team, suggests that a similar eruption under the Indian Ocean several million years before the extinction of the dinosaurs had a similarly devastating impact on the environment.
However, at this earlier time there is no evidence of any asteroid impact.
Her findings are based on analysis of microfossil assemblages, which were found inside cores that had been drilled deep into sediments on the ocean floor.
The eruptions that were responsible for these two extinction events were as a result of mantle plumes -– a phenomenon caused by rising hot mantle from deep within the earth.
Likened to the actions of a lava lamp, the mantle's heat causes it to rise and mushroom out; it then flattens causing the mantle to melt and erupt magma over the earth's surface and across an area of some 1,000 kilometres diameter.
These eruptions last between one and two million years and more than one million cubic kilometres of lava can be erupted in that time.
Today, we can witness seven huge remnants of such mantle plume activity. These are also known as 'hotspots' and are responsible for the volcanic activity on Iceland, the islands of Hawaii, Easter, Reunion, Tristan and Louisville as well as volcanism in the Afar region of Ethopia.
"Mantle plumes are literally a hot topic for debate," said conference organiser Dr Andrew Kerr of Cardiff University's School of Earth, Ocean and Planetary Sciences.
"They are a catalyst for the formation of ocean basins and fundamentally reshaping the earth's surfaces. The massive outpouring of lava, ashes, and gas can have significant effects on climate, which destabilises the environment and have the potential to dictate the course of evolution. It is likely that were it not for mantle plumes, mammals would not have become predominant, and humankind would not be here today.
"Bizarrely, amongst earth scientists, there is also a vocal minority who don't believe that mantle plumes exist at all. This conference is therefore an opportunity to address these issues and validity of the links between mantle plumes with the evolution of life by bringing together geophysicists, petrologists and palaeontologists."
You may be interested in this website: Syzygyjob.com. Jim Berkland worked for the USGS until his earthquake predictions became too accurate, and they asked him to leave. He bases his predictions on tidal stresses caused by positions of the Sun and the Moon relative to our Earth (amongst other things). I find his work fascinating.
That's it!!!! Democrats caused the demise of the dinosaurs! Kids everywhere will be so displeased...and we'll get a whole new crop of Republicans. You've solved everything! :^)
Yup, I've read about that, seems this oil 'polution' in the Gulf is 'self-cleaning' and does not cause a threat to the animals and beaches.
It would have been an impressive amount of analytical work, and I'm sorry he didn't let you do it. I've done a lot of reading about hydrostatic shock, in the context of what happens when a small supersonic object hits a large, fluid-filled object (ie, bullet hitting body).
I'm sure that a large object hitting the earth at 7+ miles/sec would generate some really impressive shock waves. Doing a good simulation of how they would travel through the earth (and taking into account wave reflection and refraction as the waves go through various boundary layers ) would be impressive even as a master's thesis
I've been hearing that too. Something about oil being created by anaerobic bacteria deep in the crust. Sulfur-reducing HAVE been found in deep oil deposits.
Red
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Moon over Chicxulub: Will Night Finally Fall on the Dinosaur-Extinction Debate?
American Scientist | November-December 1998 | Kirk Johnson
Posted on 09/21/2005 10:32:02 PM PDT by SunkenCiv
http://www.freerepublic.com/focus/chat/1489125/posts
Just some global warming thoughts:
Do higher global temperature spkes increase volanic activity? As the plates expand from higher temperatures, there would be pressure, volanic activity, etc. Then "Walla," volcanic activity increases. That causes ash to block sunlight, which in turn cools the earth. Prettier sunsets, too.
Not to mention, there would be more moisture in the air with higher temperatures, more evaporation. And as I understand it, evaporation cools. The earth would 'sweat', and the 'sweat' would be recycled, I'd imagine.
The crater is significantly smaller than the Gulf of Mexico. Since there are several other very large craters that do not seem to be associated with mass extinctions one theory has it that a key reason why this impact was so devastating was because it hit a very large carbonate platform.
OMG...hilarious!
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