Part 1-: Glacial flow is inhibited by friction. Friction is the highest at: a) t
ID: 109764 • Letter: P
Question
Part 1-:
Glacial flow is inhibited by friction. Friction is the highest at:
a) the surface of a glacier.
b) the middle part of a glacier.
c) the base of a temperate glacier.
d) the base of a continental glacier.
Part 2-:
Which of the following statements is true?
a) when alpine glaciers melt, the ice inside the glacier retreats up the valley carrying sediments with it.
b) glacier ice always flows down the valley even when the glacier is retreating.
c) when two glaciers meet, their medial moraines merge to form a lateral moraine.
d) river drainage from glaciers is and has always flowed from north to south.
e) glacio-fluvial deposits form mostly in glacial lakes.
Part 3-:
Glacial sediments provide a source of sand and gravel used in road construction. The most valuable sediments are those that are well-sorted and do not require much modification after extraction. Knowing this, which glacial deposit do you think provides the best source for gravel?
a) drumlin
b) outwash plain
c) moraine
d) varve deposit
e) roche moutonné
Explanation / Answer
1.B. base of a temprate glacier, because, base os subjected to pressure from overlying layers, and temperate glaciers have solid base compared to continetal glacier, which has water under its base.
2.A. False, when glaciers retreat, the sediments are deposited along its path before the retreat happend.They often deposit large mounds of till: gravel, small rocks, sand, and mud.
B. True. Glaciers flow down the vallley and follows slope. Because of gravitational pull.
C. True. A sediment ridge, located on a glacier’s exposed ice surface, far from valley walls, extendinng to the end of the glacie. Formed as two lateral morine combines when two glaciers meets.
D. false, glacial riversflow downhill, ie, according to gravitational slope.
E. False.
3 b. Outwash plains are formed by deposits carried in melt water of a glacier, It is water transported deposits, making it well sorted and layered.