[geeks] Disasters, was Mr Bill?
alaric at metrocast.net
Fri Sep 19 06:14:32 CDT 2008
Geoffrey S. Mendelson wrote:
> On Fri, Sep 19, 2008 at 01:06:14AM -0400, Shannon Hendrix wrote:
>> Besides, even a small asteroid can send us on a serious and
>> demoralizing detour without doing that much damage to the planet itself.
> There have been some big impacts in recorded history, nothing that wiped
> out life on earth, but some spectacular results have been noted.
> There was a big metor strike around 65 million years ago, which is
> beleived to have created the Gulf of Mexico. It's also blamed for the
> disapearance of the dinsosaurs, but there are some good theories each way.
The people who claim the Alvarez impactor created the Gulf of Mexico
don't understand basic geology or plate tectonics. It left a big impact
structure, yes; but nowhere near THAT big. The Gulf was already there
when it hit. (And in any case, the Gulf of Mexico isn't even remotely
centered on the impact site.)
An impactor big enough to create a crater the size of the Gulf of Mexico
most likely wouldn't have left a crater as such, because it would have
punched clear through the crust and exposed the mantle, causing a
massive outburst of hypervulcanism. (Though current theory says the
Deccan Traps in India, which lie directly opposite the Yucatan, are the
footprint of hypervulcanism triggered by the focused shockwaves from the
impact travelling through the Earth, just as the "weird terrain" in
Mercury's south polar region is believed to have been created by the
focused shockwaves from the impactor that blew a divot off its north
Phil Stracchino, CDK#2 DoD#299792458 ICBM: 43.5607, -71.355
alaric at caerllewys.net alaric at metrocast.net phil at co.ordinate.org
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