Geography Reference
In-Depth Information
These facts mean that boring down into the ice cap is rather like going back in time. The deeper
you bore, the older the ice — and thus the older the precipitation (snow) of which the ice is made.
Moreover, because precipitation captures minute but measurable amounts of atmospheric gases, it
constitutes a record of the nature of the atmosphere at the time that it fell. Thus, the ice caps are im-
portant sources of information about the atmosphere and climates long ago, which figures promin-
ently in contemporary inquiry concerning global warming and its causes.
