Chapter 14

Question 1

Glacial system input

Answer 1

-10% of Earth’s land surface; 95% in Antarctica and Greenland
-input to system in precipitation as snow, insufficient solar radiation to melt
-input is a combination of ice and mineral debris and eventually lose as meltwater

Question 2

Geographical and topographical features that influence climate in the glacier system

Answer 2

latitude and distance from the ocean; altitude, relief, aspect influence precipitation and temperature

Question 3

System Function of glacial system

Answer 3

Inputs: snow and rain; outputs: ablation (melting of the glacier); movement of the ice causes calving as large pieces break off

Question 4

calving

Answer 4

the breaking of ice chunks from the edge of a glacier

Question 5

ablation

Answer 5

the process of losing mass from a glacier due to melting, sublimation, evaporation, calving, or wind erosion

Question 6

Transfer of mass in glaciers

Answer 6

• Internal shearing or deformation
• Basal sliding – glacier over its bed
  -glaciers are a frozen drainage system

Question 7

basal sliding

Answer 7

The temperature at the base of the glacier is above the pressure melting point, allowing melting to occur.
Meltwater acts as a lubricant, reducing friction and allowing the ice to slide over the valley floor.
It involves mechanisms such as rapid creep in the basal layers, pressure melting, and slippage over a layer of water at the bed

Question 8

Erosion processes in glaciers

Answer 8

• Rock fracturing
• Abrasion - sliding
• Meltwater - short periods of high
  discharge, strong pressure gradients and
  high gradient subglacial channels, high
  flood peaks are assoc with high velocities
  and turbulent flow. Temperature is colder,
  making it more viscous, reduces the fall
  velocity of suspended sediments giving
  higher concentrations – erosion of channel
  margins by sediment-, ice- and bedrock
  laden waters, by high turbulence and
  cavitation.

Question 9

Material transfer in glaciers

Answer 9

• Entrainment
• Glacier power and transportation

Question 10

entrainment

Answer 10

how it picks it up and moves things down the slope

Question 11

deposition processes in glaciers

Answer 11

• Deposition by ice: Till deposits
• Unstratified
• Poorly sorted, clasts of all sizes
• Variety of minerals, rock types, and
  weathering
• Variable in shape
• Preferred orientation: you can tell the direction the glacier was moving based on where materials are
• Meltwater deposition
• Similar to fluvial deposits, sorted and
  stratified