Geography Reference
In-Depth Information
Figure 2.1
The three slowly changing and cyclical mechanisms related to the
Earth's orbit around the Sun that impact the energy that reaches the
Earth's surface.
23,000 years. The eccentricity effect causes the seasons in one
hemisphere to become more intense while the seasons in the other
are moderated. The greater the tilt effect the more intense the
seasons in both hemispheres become; summers get hotter and
winters colder. The wobble determines where in the orbit the
seasons occur, and most importantly the season when the Earth is
closest to the Sun. The Earth currently reaches its furthest point
from the Sun during the southern hemisphere winter. Therefore,
southern hemisphere winters are slightly colder than northern
hemisphere winters while southern hemisphere summers are
slightly warmer.
It is remarkable that scientific evidence from marine sediments
and other sources shows that the timescale and frequency of the
