Author Question: Changes in Earth's elliptical orbit around the Sun (eccentricity) varies over a ________ year cycle. ... (Read 72 times)

humphriesbr@me.com · **on:** Jul 14, 2018

Changes in Earth's elliptical orbit around the Sun (eccentricity) varies over a ________ year cycle.

A) 100,000 B) 175,000 C) 12.000 D) 41,000 E) 26,000

Question 2

What is the importance of the Pleistocene Epoch to the modern day?

What will be an ideal response?

brbarasa · **Reply #1 on:** Jul 14, 2018

Answer to Question 1

A

Answer to Question 2

Answers may vary because of the long-lasting influence.
During the Pleistocene, almost a third of the Earth's land surface was buried beneath ice sheets and glaciers. This epoch began approximately 2.5 million years ago and consisted of at least 18 expansions and retreats of ice sheets over much of Europe and North America. The ice sheets disappeared about 7,000 years ago, leaving important landscape remnants behind.
Among the features that resulted from the Pleistocene glaciation are the five Great Lakes in North America, which formed as repeated glaciation enlarged and deepened stream valleys to form the future lake basins. Sea levels were also much lower (100 m; 330 ft) than today.
Areas that are now arid had much more rainfall, contributing to the formation of several very large pluvial lakes, such as Lake Bonneville and Lake Lahontan. The Great Salt Lake is one of several remnants of Lake Bonneville. As the conditions changes, these lakes mostly dried up.