systems and processes

Question 1

what is a glacial budget?

Answer 1

this is the mass balance of a glacier/the difference between accumulation and ablation

Question 2

what is a postive glacial budget?

Answer 2

when accumulation exceeds ablation

Question 3

what is a negative glacial budget?

Answer 3

when ablation exceeds accumulation

Question 4

what are the two types of glaciers?

Answer 4

warm based and cold based

Question 5

explain the features of a warm based glaciers (temperate)

Answer 5

summer winter
surface temp ≈5°C ≈-10°C
base temp <0°C <0°C

climate > fluctuating
features a lot of meltwater
processes: basal sliding and internal deformation

Question 6

exlplain the features of a cold based glacier

Answer 6

summer winter
surface temp ≈-15°C ≈-20/30°C
base temp <-10°C(below PMP) <-10°C

climate > consistently dry and cold
features little meltwater
processes: ONLY internal deformation and little basal sliding

Question 7

name the geomorphological processes

Answer 7

weathering: frost action and nivation

ice movement: internal deformation, compressional flow, extensional flow, rotational slip, basal sliding

erosion: plucking and abrasion

Question 8

define the process of frost action

Answer 8

water gets into cracks, freezes into ice and expands by 10% this puts pressure and causes it to break

Question 9

define the process of nivation

Answer 9

when snow gathers in a small depression and erodes into a hollow ful of snow. (common in periglacial environments)

Question 10

define the process of internal deformation

Answer 10

deformation of layers of ice is caused by the pressure from weight, causing layers to move faster

Question 11

define the process of compressional flow

Answer 11

when ice hits a shallow area, so friction slows ice to build up and compress=thicker ice

Question 12

define the process of extensional flow

Answer 12

when ice meets a steep gradient so velocity increases making it thin and stretch. this causes cracks and crevasses

Question 13

define the process of rotational slip

Answer 13

compressed ice is trapped in a hollow and gravity continues to move it down. aswell as meltwater assisting it to move > eroding the hollow

Question 14

define the process of basal sliding

Answer 14

the glacier slides over bedrock due to lubrication from the meltwater

Question 15

define the process of plucking

Answer 15

this is when rocks are attached to bedrock and become frozen to the glacier, as the glacier moves, rocks are plucked leaving a jagged surface

Question 16

define the process of abrasion

Answer 16

the sandpaper effect by small rocks leaving a smooth surface with small sitrations (scratches)

Question 17

name the periglacial processes and features

Answer 17

permafrost, active layer, frost heave and solifluction

Question 18

what is permafrost?

Answer 18

permafrost is ground that is permanently frozen for atleast 2 years

Question 19

what is the active layer?

Answer 19

the top layer of the permafrost that thaws in the summer

Question 20

what is frost heave?

Answer 20

water gets underneath a substrate/rock and freezes. this expands and forces it up

Question 21

what is solifluction?

Answer 21

the movement of soil that becomes water logged when water is trapped between active layer and permafrost. this flows down with gravity