GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2007-05 > 1179864676
From: (John Chandler)
Subject: Re: [DNA] Comet set fire to Northern Hemisphere 13000 years ago?
Date: Tue, 22 May 2007 16:11:16 -0400 (EDT)
References: <firstname.lastname@example.org><002501c79ba2$8c600a20$650fa8c0@Villandra2><00ac01c79bac$8405c7c0$6401a8c0@HP><EB545C1B-886A-42F3-AAE9-68BDAE89705A@vizachero.com> <000601c79bc4$a2a29dd0$6401a8c0@HP><006d01c79bd0$12bb34f0$01fea8c0@margiesmail><46523BD0.email@example.com> <00c601c79c6b$5bc04730$01fea8c0@margiesmail><001d01c79c64$d4726d40$1dc26a4a@PAKINCAID><firstname.lastname@example.org><016001c79c99$086e8aa0$01fea8c0@margiesmail>
> The basic mechanism behind
> Hapgoods work was the building up of the ice-pack during an ice-age and
> creating an off-axis load at the poles. As the pack gets higher, and
> heavier, a point is reached when the force is sufficient to cause a slippage
> of the crust around the visco-elastic layer.
It's not that simple. This idea ignores plate tectonics and isostasy.
Of course, the latter is not instantaneous, but it starts to compensate
for the ice load as soon as the ice starts to build up. Meanwhile, the
crust is continually being shoved around by convection cells in the
mantle -- slippage is not as easy as you might think.
|Re: [DNA] Comet set fire to Northern Hemisphere 13000 years ago? by (John Chandler)|