Geology Reference
In-Depth Information
Figure 4: Gaia's temperature over geological time.
(
re-drawn from K.C. Condie and R. E. Sloan, Origin and Evolution of Earth: Principles of His-
torical Geology, Prentice-Hall, 1998
)
The message of a self-regulating Earth has also been found by scientists working in the
Antarctic, who have extracted cores of ice from the frozen continent that contain air
bubbles trapped by swirling snow up to 700,000 years ago
(Figure 5
which shows a part
of this record). By analysing the air held in these bubbles along the length of the core it
has been possible to discover how carbon dioxide and temperature have varied together
over this vast span of time.
