Fw: cause of death at KT

[don ohmes <d_ohmes@yahoo.com>]

See below--
Don
----- Original Message ----
From: Scott <hmwh@together.net>
To: DINOSAUR@usc.edu
Sent: Thursday, August 31, 2006 10:31:43 AM
Subject: cause of death at KT

Franklin Bliss wrote
"Disruption of the food chain, disease, climate change, fires, habitat
disruption, acid rain, competition for limited resources and other  causes
all had an effect on the overall extinction process at the K/ T. "

I'd say, for North America at least, don't forget the blast wave of the
impact as cause of death factor.

If the boys from Arizona (Marcus, Melosh, and Collins) are right in their
algorithm for computing effects of an impact, then even at 1500 kilometers
away from the site the blast wave is still traveling at 164 m/s (366 mph),
given an impact angle of 45 degrees, an impacting object density of 3000
kg/m cubed and an impact velocity of 32 km/sec (about 20 miles/s). I don't
know when the curvature of the earth sends this blast wave off overhead.
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There's a couple of web pages on this (search on Steven Sque), or you can drag 
Pythagoras out of the closet--

Assuming the Earth is a sphere, a man sitting on the ground could see only the 
tip of a tower ~174km tall at a linear distance of 1500km. In other words, 
given a line tangent to an earth-sized sphere, a point 1500km from the point of 
intersection has an altitude of ~174km. This implies that there would be 
considerable blast wave divergence from the surface of the Earth at that 
distance. All in all, though, things might be easier at ground zero. }: D

Don

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What does that heavy a blast wave do to living flesh 1500 k away from its
source? There would be shadowed areas not affected, I suppose. But if you
are a small shrewlike critter happenstancely burrowed in when the blast wave
goes overhead, what happens? Does all the air get sucked out of your burrow?

Scott Perry