PLEASE ANSWER BOTH OF THESE QUESTIONS PLEASE ANSWER BOTH OF THESE QUESTIONS PLEA
ID: 287123 • Letter: P
Question
PLEASE ANSWER BOTH OF THESE QUESTIONS PLEASE ANSWER BOTH OF THESE QUESTIONS PLEASE ANSWER BOTH OF THESE QUESTIONS 2. During the last Ice Age, scientists think there were many cycles of growing and shrinking glaciers; each cycle lasted about 100,000 years. A. Explain why plate movements could not be the cause of these cycles within the Ice Age. (4 points) B. What is the theory for what caused these cycles? (6 points) 3. Glaciers are often described as advancing or retreating. A. Explain what happens when a glacier retreats. (5 points) B. Can a glacier accumulate new snow while it is retreating? Why? (5 points)Explanation / Answer
2. A.) Although the landlocked Arctic and the Antarctica sitting at the south pole is a suitable tectonic position for the present Earth to call for a glacial period of the ice age, it is not nearly enough. The growth of ice sheets was particularly due to the plummeting temperature of the Earth resulting from the rapid CO2 drawdown in the atmosphere and orbital eccentricity of the Earth. The rapid growth and retreat of ice sheets cannot be explained/caused by the plate movements. Moreover, the plate movements have been going on for billions of years but ice ages are rather rare phenomena in the huge Geological Time Scale.
B.) In an Ice Age, two distinct conditions prevail alternatively. A colder 'Glacial' period followed by a warmer 'Interglacial' period. We are now in the interglacial period of the last ice age, where the ice sheets have melted and retreated back to the polar region. That was about 11,700 years ago. The reasons behind this include but not restricted to:
Milankovitch cycles: According to this theory the variations in the eccentricity of Earth's orbit, as well as its axial tilt, directly affect the solar radiation reaching Earth periodically over 40,000 years to 100,000 years, in turn bringing large-scale climatic fluctuations. The building up of glaciers and their melting corresponds with the periodic cycles of the astronomical attributes.
Atmospheric CO2: Atmospheric CO2 , Methane and other gas concentrations have direct impact on glacial and interglacial periods. Polar ice cores are now revealing that those gases, especially concentration of CO2 in the atmosphere were low everytime a glacial period occurred in the Earth's history. The lowering of CO2 in atmosphere triggered rapid temperature fall and augmented the ice sheet growth.
variation in Solar energy output, volcanism, and fluctuation in ocean currents also held reasons behind widespread climate change.
3. A.) When the ablation is more than accumulation a glacier retreats. When it melts, the dynamicity of the mass decreases and low energy conditions force it to deposit the sedimentary load. Retreating glacier enters into a depositional setting. During deposition, it forms numerous landforms such as moraines, drumlins, kames, esker, Roches moutonnées , kettle lakes etc. The major kind of deposits are till and outwash sand. Isostaic rebound also takes place after the huge glacial mass melts away.
B.) Glacier mass balance dictates glacial ablation. if during ablation, rate of accumulation somehow increases it can accumulate new snow.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.