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

NORTH AMERICA AT THE POLE 2OQ
thinking about the carbon dioxide is that the assumption of
a cumulative increase in the proportion of the gas in the air,
during the movement of the crust and the waning of the ice
sheet, helps to explain not only the extraordinarily rapid
final melting of the ice but also the succeeding Climatic
Optimum.
The Climatic Optimum is the most important climatic
episode since the end of the ice age;
the fact of the occur-
rence is well attested, but it is unexplained. Scientists have
been aware that this 2,ooo-year warming of the climate could
have resulted from an increase in the carbon dioxide con-
tent of the air, but this has not been helpful, since hitherto
no way has been found by which to account for an increase
of the required magnitude. No other possible cause of the
warm phase (such as an increase in the quantity of the sun's
radiant heat) has been supported by tangible evidence. It
seems that the assumption of a displacement of the crust
furnishes the first possibility of a solution.
To return, for a moment, to the question of the several
readvances of the ice, it may be asked, Why did the volcanism
occur in massive outbursts separated by quieter periods?
the whole movement of
Why was it not continuous through
the crust? Campbell has suggested an answer. It is quite
possible that the fracturing of the crust, necessary to permit
the displacement, was itself spasmodic. We may assume that
when the mounting bursting stress brought to bear on the
crust by the growth of the icecap finally reached the critical
point (that is, the limit of the crust's strength), considerable
fracturing occurred in a rather short time, accompanied by
massive volcanism. The crust would now start to move, and
it would continue to move easily to the distance permitted
by the extent of the fractures so far created. The movement
might then come to a halt, and the accompanying volcanism
would tend then to subside. Meanwhile, on the poleward
side of the icecap the ice still would be building up,
and the bursting stress resulting from it would again be on
the increase. New fracturing would eventually occur, with