Glaciers - Processes Flashcards
glaciers
- slow-moving mass of ice formed by the accumulation & compaction of snow
- persistent body of dense ice
ice shelves
permanent floating sheets of ice connected to a landmass
ice sheet
glacial ice more than 50,000 square kilometres
formation
- snow accumulates + compressed into ice
- snow builds on top in new layers compressing even further
- 30-40 years for snow to form dense glacial ice
movement
- gravity
- meltwater at the base which helps, known as basal slip
crevices
ice gets streched/squashed = cracks
glacials/ice ages
- cold periods
- nearly reached london
interglacials
warm periods
glacial budget
ablation
- melting zone
- ice is lost from budget
glacial budget
accumulation
- material builds up
- added to glacial budget
glacial budget
calving
- splitting the end of icebergs
- can become icebergs if snout is in the sea
glacial budget
inputs
fresh snow + avalanches
outputs
- melting
- evaporation
- sublimation
- calving
glacial budget
- inputs and outputs of glacial system + overall balance between them
- if input > output, glacier grows
plucking
melt water freezes onto rocks, as th glacier moves it rips out those fragment = rough, jagged surface
weathering
- rock is open to attack from the weather
- diff between erosion is that it erodes the rock in its original position
freeze-thaw weathering
- water enters crack in rock
- water freezes, expanding
- water will melt, repeat
subglacial moraine
material carried underneath glacier
englacial moraine
material within the glacier
supraglacial moraine
moraine on top
terminal moraine
final point the glacier and moraine it was pushing infront
snout
front of glacier
bulldozing
pushing material infront of it
