Often when we speak of the Ice Age, we refer to it ending when all the ice that covered the area "retreated." Did the ice actually start to move toward Canada, or did it start melting from South to North once temperatures rose, which made it appear to "retreat"?

-- Ron Testa, Jr. (jtesta@oswego.edu), April 26, 2001

Answers

According to our notes on Glacial Processes, when we are referring to the Ice Age retreating we are saying that the ice began to melt. Evidence for this can be found in glacial abrasions on bedrock. The smooth side of the scratches indicates the direction that the ice moved towards. If the glaciers had "truly" retreated, there would be smooth scratches in both directions (advance and then retreat).

This melting took place from the point closest to the equator as variations in the climate changes caused the earth to become warmer, (due to the tilt of the earth on it's axis) the ice began to melt. This caused a variety of deposits and landforms to be created out of the "dropping and carving" by the glacial mass (ie. morraines, drumlins, etc).

-- Terry McCall (mccall@oswego.edu), April 30, 2001.