Lecture 15

Question 1

Why is land ice important

Answer 1

increases albedo

Question 2

Melting of land ice leads to what

Answer 2

sea level rise, and freshening of the oceans in polar regions

Question 3

Importance of land ice and water supply

Answer 3

Glacier melt helps with the dry season to provide water for drinking, irrigation, industry, electricity. Important in asian countries around himalayas

Question 4

What would lead to growth of land ice (earth tilt)

Answer 4

Less tilt

Question 5

How are glaciers formed

Answer 5

More snow accumulates than melts, With melting/sublimation and refreezing, crystals change shape and become dense ice

Question 6

What is a glacier

Answer 6

Permanent body of ice, consisting largely of recrystallized snow has downslope or outward movement from its own weight

Question 7

Cirque glacier

Answer 7

Bowl shaped depression

Question 8

Valley glacier

Answer 8

When a cirque expands out and flows downward into a valley

Question 9

Tidewater glacier

Answer 9

When a valley glacier reaches the sea

Question 10

Ice caps

Answer 10

Form in relatively flat but high elevation areas, ice flows away from highest point towards the edge <50,000 km

Question 11

Ice sheets

Answer 11

only found in Antarctica and Greenland today, continental size masses >50,000km

Question 12

Ice shelves

Answer 12

Only found around Greenland and Antartica, Where ice sheets extend onto sea and float on water

Question 13

Glacier types based on temperature

Answer 13

Temperate glacier - Atmospheric temperatures high enough for glacial ice to be at or near melting temp

Polar glacier - where atmospheric temps are so low that ice stays below melting temperature

Question 14

Accumulation

Answer 14

Is the addition of ice to the glacier

Question 15

Ablation

Answer 15

Is the loss of ice to the glacier

Question 16

Glaciers: Ablation

1 - sublimation

Answer 16

Common in tropical glaciers, ice goes to water vapor results in peitentes

Question 17

Glaciers: Ablation

2 - Surface melting

Answer 17

Significant part of mass balance on mountain glaciers and the Greenland ice sheet, differs summer to summer.
Leads to supraglacial lakes, once formed the promote extra melting

Question 18

Glaciers: Ablation

3 - Basal melting

Answer 18

Occurs underneath ice shelves and floating parts of tidewater glaciers due to warmer ocean water beneath, Geothermal from earth can heat the base of glacier

Question 19

Glaciers: Ablation

4 - Calving

Answer 19

Separation of ice blocks from glacier