No. 128: MAR-APR 2000
What could have perturbed the earth? One suggestion blames a sudden shifting of the planet's mass distribution, some sort of subterranean indigestion, like a subducted ocean plate suddenly plunging through into the lower mantle.
(Kerr, Richard A.; "Did the Dinosaurs Live on a Topsy-Turvy Earth?" Science, 287:406, 2000.)
The biological consequences of such a sudden tilting could have been severe.
The event -- known as rapid true polar wander -- may have been accompanied by worldwide volcanic upheavals and reorganization of tectonic plates that would have played havoc with anything living in the Late Cretaceous period, 65 million to 99 million years ago.
Although the notion that an asteroid was the immediate cause of dinosaur extinction about 65 million years ago has won wide acceptance, many paleontologists have argued that volcanic activity may have played a role in changing the climate and sending populations of the giant creatures into decline.
(Bowman, Lee; "Scientist's Say Earth's Magnetic Field Shifted Rapidly in Time of Dinosaurs," Dallas Morning News, January 21, 2000. Cr. Phelps)
Comment. Coincidentally (honest!), we are offering with this mailing a reprint of C.H. Hapgood's The Path of the Pole.
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