Glacial Lake Agassiz went through many periods of catastrophic ...

[Marty]

Glacial Lake Agassiz went through many periods of catastrophic drainage starting at 13,000 years ago. Some of these periods of catastrophic change have been linked to periods of cooling climate,
 
  particularly when the lake drained through the St. Lawrence Seaway and into the North Atlantic. How would the drainage of Lake Agassiz affect the climate to such a degree that cooling would result?
  What will be an ideal response?

Question 2

The Mississippi River currently makes up the western boundary of the state of Illinois. However, the Ancient Mississippi River Valley once flowed through the center of the state,
 
  cutting off one-quarter of the state from its modern boundaries. How did the Mississippi River shift from its ancestral location to its present one? How did it end up staying in its current location? Explain.
  What will be an ideal response?

[Heffejeff]

Answer to Question 1

Answer: Lake Agassiz was a cold, proglacial lake, so when such large volumes of cool freshwater were jettisoned into the North Atlantic, they rested on top of the saltwater because of the freshwater's lower density. This process changed the turnover point near Iceland for the Thermohaline Circulation Current (THC). Instead of bringing warm water and warm air masses farther north, the THC was deflected farther to the south. The result was a colder climate.

Answer to Question 2

Answer: During the Illinois Episode Glaciation, the advancing glacial lobe from the Lake Michigan basin spread westward across the state. This process diverted the river into modern eastern Iowa, where the river flowed along the margin of the ice and created the curved streambeds of the lower Cedar and Wapsipinicon Rivers. At the end of the glaciation, the glacier retreated, and the Mississippi resumed its ancestral course. However, during the Wisconsin Episode Glaciation, meltwater from the Lake Michigan Lobe deposited large outwash plains in central Illinois, filling the ancestral streambed, and the Mississippi was diverted to its current location.