Assignment task:
The onset of a period or stage of glaciation is due to a change in Earth temperature and circulation. It is generally accepted that a global decrease of 4o to 5o C, especially during the summer, and a substantial increase in the amount of snowfall in subarctic and arctic regions is necessary for the onset of a glacial episode. Several theories have been proposed for such a change in climate -- reductions in solar radiation due to meteorite collisions with the Earth, increased volcanism, the shifting location of continents, and the uplift of vast mountain regions. Milutin Milankovitch proposed one of the most significant theories to account for climate change by variations in Earth orbit. Changes in the eccentricity of earth orbit, the degree of deviation of the orbit from a perfect circular path, is thought to cause the necessary change in insolation to decrease global temperatures. Recall that the Earth's orbit is elliptical, but over periods of 100,000 years the shape varies. The changes in orbit have been correlated with ocean sediments that record the history of glacial stages. The cyclical nature of warming and cooling correspond well with the estimated dates of glacial and interglacial periods. In addition to the change in orbit, the Earth "wobbles" on its axis which alters the amount of insolation reaching the surface of the Earth. [For more about the causes and stages of glaciation in earth history.
Explain how one (1) of the following concepts affects Ice Age periods on Earth through time: Eccentricity of Earth's Orbit should include information on how Paleoclimatology is used to prove the concept/theory. Please reference what we learned earlier in Chapter 2: The Earth System as a way to compare and contrast how Earth is currently oriented in space, versus changes that occur throughout Geologic Time that leads to periodic Ice Age cycles.