The Earth's Shifting Crust by Charles Hapgood - wire of information

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EARTH'S SHIFTING CRUST
into the sea rather than to bring about a transfer of centrif-
ugal momentum from the icecap to the crust. This objection
has a certain plausibility at first glance, and yet it is invalid
for the following reason. We know that according to classical
mechanics any mass deposited upon the earth's surface (provided
that surface is already in gravitational equilibrium) will
be acted upon by the earth's rotation, and will give rise to a
effect. So much cannot be denied. It is also true
centrifugal
that the resulting centrifugal momentum will act upon the
ice and can be expected to accelerate to some degree the
rate of flow of the ice in the direction of the thrust (not in
all directions). In the case of the present Antarctic icecap
this might mean a slightly increased rate of flow across the
broadest section of the continent, in the direction of the
meridian of 96 E. Long, (see the map of Antarctica, Intro-
duction, p. 18). However, the crux of the matter is, obviously,
the ratio of the rate of flow to the rate of accumulation of the
ice. It is clear, on the one hand, that new ice, until brought
within the equilibrium surface of the globe by isostatic ad-
justment, must give rise to centrifugal effects; and on the
other hand it is quite clear that, despite this, the icecap has
continued to accumulate. Why does it happen that the centrifugal
effect does not produce a flow-off of ice from the
continent at a rate equal to the rate of accumulation? The
answer to this is, obviously, that ice presents considerable
resistance to flow. It flows only under considerable pressure,
and is otherwise a solid. Moreover, in Antarctica, and pre-
sumably in any polar icecap, the prevailing low temperatures
cause the ice to have increased rigidity. It is also thought that
the ice below the superficial layers of a great ice sheet is stagnant,
and that only the upper layers move. This means that
the ice that is in contact with the ground is fixed to the
earth's surface. The viscosity, or stiffness, of the ice in turn
means that a drag is imparted by the upper layers to the
lower layers, and by them to the underlying crust. Thus the
centrifugal momentum is transmitted to the crust. Finally,
the supposition of the gliding off of the icecap is rendered