2 lab assignments 1

Complete the Two lab writes ups at the bottom of these assignments.

1.

Summarize the relationship between accumulation and ablation over the course of a glacier.

What relationship between accumulation and ablation is necessary for glaciers to form? How

wil

l the relationship between accumulation and ablation change b

etween a glacier

’

s head and

its toe? How will it change between winter and summer?

2.

Compare and contrast the Nabesna and Athabasca Glaciers. Identify

and describe

three

dimensions of climate which cause the Nabesna Glacier to extend over a much la

rger distance

than the Athabasca Glacier. (HINT: remember our framework of

climate controls

—

how

will they

affect the relationship between accumulation and ablation?)

3.

In our video tour, we contrasted summer and winter

(or, at least, late

–

spring)

views of the

Victoria and Lefroy glaciers. Although snow accumulates nearly everywhere during the winter

months, in o

nly a few areas does this snow endure to form glaciers. What is special about these

areas of glacial formation?

4.

The glaciers we examined in the Canadian Rockies all end at 6700

–

7500

’

e

levation. Why

do

glaciers not extend below this altitude?

(HINT: What effects will altitude have on the

relationship between accumulation and ablation?)

5.

What landforms indicate the previous influence

of glaciation

in the valleys below the Athabasca,

Victoria, Lefroy, and Bow Glaciers?

6.

What elements of the landscape near Geor

getown, Colorado, indicate the presence of glaciers

in Colorado

’

s past? How can you tell that

this glaciation took place in the distant past, in

contrast to the relatively recent glacial activity in the Canadian Rockies?