Range of Glacial Environments

Question 1

What are the different types of ice mass?

Answer 1

• ice sheet
• Piedmont glacier
• valley glacier
• sea ice
• ice cap
• ice field
• cirque/corrie glacier

Question 2

Ice sheet:
1. What is it?
2. How did it form?
3. How big is it?
4. Give an example
5. Constrained or unconstrained?
6. How has the global distribution changed?

Answer 2

1. When ice on land completely submerges the regional topography forming a gently sloping dome of ice which can be several km thick in the centre
2. • Snow falls/compresses/firn
   • firn layers build up and glacier moves under the weight, compression and geothermal ice meltwater
   • flows over everything from the centre out, covering it, acting like plastic
3. 100,000-10 million square km
4. Greenland/Antarctica
5. Unconstrained
6. During Pleistocene, 1/3 of land was covered, much of the N hemisphere was covered

Question 3

Ice cap:
1. What is it?
2. How big is it?
3. Give an example
4. Constrained or unconstrained?
5. How has the global distribution changed?

Answer 3

1. Ice occupying upland areas, a smaller version of an ice cap. Drained by outlet glaciers
2. 3 - 10,000 square km
3. Vatnajokull (Iceland)
4. Unconstrained
5. During Last Glacial Maximum they were more widespread. Mountain glaciers nowadays used to be ice caps e.g. in Alps and there were enormous ones in Tanzania, compared to only one now in the whole of Africa