Please answer all the following questions correctly since they are related to th
ID: 292360 • Letter: P
Question
Please answer all the following questions correctly since they are related to the graph.
Figure: The location of terminal moraines during the North American glacial stages.
1- Based on the map in the figure above, how many times did the glaciers advance southward into North America?
2- During which superstage did glaciers extend farthest south? During which did they extend least far south?
3- How much further did the glacier extend when at its maximum extent compared to its extent during the other glacial stages?
4- What do you think would happen to an exisiting moraine if the glacier during a later interval extended farther south?
5- Why does the isotope record of global temperatures reveal many short glacial stages whereas the moraine record shows only a few major glacial advances?
0180 320 km Illinoian Wisconsin Kansan NebraskanExplanation / Answer
ANSWER-
1.) Based on graph 4 times the glaciers did advance southward into north America.
2.)During Illinoian stage the glaciers extended farthest south and during wisconsin stage they extended least far south.
3.)the maximum extent is seen during the newest Illinoian stage and minimum extent is seen during the nebraskon stage which is oldest pleistocene episode of glaciation.The glacier has extended much towards South during these epochs.
4.)The existing moraine if small will be obliterated by the later glaciation and the larger moraines will undergo change due to small moraines production or superposition of new moraines.
5.)Since moraines are the last stage glacial landforms and gives the ultimate form ,isotopic studies show incrementially the mechanism involved in forming the landforms.It has been found through isotopic studies that the two oldest stages nebraskan and kansan represents multiple glacial events of widely differing age and are termed as pre-illinoian.