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

164
EARTH'S SHIFTING CRUST
it makes no difference whether the excess mass that creates
the centrifugal effect is constituted of ice or whether it is in
part constituted of rock. It may be concluded, therefore, that
the isostatic process itself is ineffective in counteracting the
centrifugal effects of icecaps.
We may conclude, then, first that the rate at which isostasy
may work is too slow to keep up with the deposition of the
ice; and second, that in so far as it does work it will not elimi-
nate the centrifugal effect of the uncompensated mass, but
will merely substitute rock for ice.
2. The Antarctic Icecap Is Growing
The theory presented in this book requires, of course, that a
polar icecap should grow, and continue to grow, though not
perhaps steadily, until it is big enough to move the crust. In
this connection it is important to examine certain current
ideas about the Antarctic icecap.
It is widely believed that the Antarctic icecap, like some
ice fields in the Northern Hemisphere, is in recession, and
was once greater than it is now. This is a mistaken impression,
the error of which can be easily shown, even without
any more data from Antarctica. I will venture to remark,
indeed, that any further data from that continent are likely
to show that the icecap there is in a phase of rapid expansion.
I will begin with the northern ice fields, about which more
is known. There is no doubt that most of them are melting,
but the exceptions are very significant. These include the
Greenland icecap, which appears to be holding its own
(after having considerably expanded since the Viking settlements
there during the Middle Ages), and the Baffinland
icecap, which is growing. The mountain glaciers of the American
northwest have, apparently, started a readvance (329).
The most important fact regarding those northern ice fields
that have been in retreat is that their retreat began only
about the year 1850, and that, before that, they were expand-