1a) systems
Glaciated landscapes - parts of earth shaped by glaciers in the past and present.
Geological time scale - system of chronological measurement used to describe
timing and relationships between events in earth's history
Past distributions - ice ages
• long term reduction in earths temperature, continental and polar ice
sheets expand
• Last ice age - Pleistocene glaciation - 2mil till 10,000 years ago
• During ice ages there are
o Glacial periods - cold and dry climate where ice grows
o Interglacial periods - warmer periods where ice and valley glaciers
retreat (present - Holocene)
Present glacier activity
• High latitude areas - Greenland
• High altitude areas - the Alps
• Local scale factors - relief / slope aspect
Glaciers
• mass of ice in motion
• Powerful erosion agent - when it moves it picks up sediment and along
with heavy weight erodes the land
Systems - transfer and store energy through inputs, outputs, throughput and
stores
Open system - energy and matter can enter from neighbouring systems as
inputs or be transferred to neighbouring systems as outputs
Dynamic equilibrium - system responds to disturbance and changes till
equilibrium is restored
Positive feedback - changes enhance
Glacier mass balance
• Difference between accumulation and ablation
• Positive mass balance - accumulation > ablation
• Negative mass balance - ablation > accumulation
• Equilibrium - ablation = accumulation
Accumulation zone
• Positive mass balance
• Origin of glacier high in the mountains where snowfall is high leads to
formation of ice
• Factors affecting growth:
o Climate - shorter summers mean less ablation and snow remains
permanent
o Further snow - gradual accumulation of snowing turning to firn,
then ice.
, o Aspect
Ablation zone
• Negative mass balance
• Snout of glacier - lower elevations have higher average temps so ice
melts
• Factors affecting decay:
o Higher summer temps - lead to negative mass balance causing
retreat
o Calving
Inputs
• Precipitation
• Thermal energy
• Potential energy
• Kinetic energy
• Melt water
• Avalanches
• Material (from deposition etc.)
Outputs
• Sediment
• Calving
• Ablation
• Sublimation
• Evaporation
• meltwater
1b) influences on glaciated landscapes
,CLIMATE:
• Wind:
o Can shape landscape through aeolian processes (wind driven
processes like erosion, deposition and transport) in particularly fine
material deposited by meltwater
• Precipitation:
o Major input (snow, rain, sleet) in glacial system
o Can be affected by latitude, altitude and seasonal variation
o High in high altitude but low in high latitude
o Higher altitudes have greater seasonal variation than higher
latitudes
o The greater seasonal variation the greater variation in mass
balance
• Temperatures:
o Temps >0ºC = higher ablation and outputs
o Greater variation in high altitudes as there is seasonal variation
o High latitudes have less temp variation but never >0ºC so despite
low precipitation ice sheets are thick
Altitude
o Even at low latitudes highest points have ice
o Temp decreases at rate of 0.6ºC/100m increase in height
Latitude
o High latitude = dry/little seasonal variation
o Contrasts to high altitudes in low latitudes as there is more seasonal
variation so dynamic valley glaciers will shape the landscape more
GEOLOGY:
• Lithology - physical/chemical composition of rocks
o Basalt - strong structure with interlocking crystals make it more
resistant to erosion
o Limestone - chemically weaker and soluble in weak acids makes it
more vulnerable to chemical weathering
• Structure - properties of individual rocks
o Jointed/permeable rock - allows water through joints and can easily
exploit joints through solution and freeze thaw processes
o Porous rocks - presence of small air spaces allows water to enter
and freeze thaw and solution can take place
o Angle of dip - where rocks incline profiles follow the angle - valleys
sides are steeper where there is horizontally bedded rock
Relief
o The steeper the relief the more potential energy due to the greater force
of gravity so the glacier will have more energy to move downslope
Aspect - direction a slope faces
o Facing away from the sun means temps will remain 0ºC for longer so less
melting will take place and they will have a positive mass balance
making them advance downslope
o The higher the mass balance the larger the erosive power the glacier has
so greater shaping of landscape
, Melt water
o Can be input/output
o Increases velocity of glacier so reaches lower altitudes quicker
1c.a) glacial ice formation
Glaciated landscapes - parts of earth shaped by glaciers in the past and present.
Geological time scale - system of chronological measurement used to describe
timing and relationships between events in earth's history
Past distributions - ice ages
• long term reduction in earths temperature, continental and polar ice
sheets expand
• Last ice age - Pleistocene glaciation - 2mil till 10,000 years ago
• During ice ages there are
o Glacial periods - cold and dry climate where ice grows
o Interglacial periods - warmer periods where ice and valley glaciers
retreat (present - Holocene)
Present glacier activity
• High latitude areas - Greenland
• High altitude areas - the Alps
• Local scale factors - relief / slope aspect
Glaciers
• mass of ice in motion
• Powerful erosion agent - when it moves it picks up sediment and along
with heavy weight erodes the land
Systems - transfer and store energy through inputs, outputs, throughput and
stores
Open system - energy and matter can enter from neighbouring systems as
inputs or be transferred to neighbouring systems as outputs
Dynamic equilibrium - system responds to disturbance and changes till
equilibrium is restored
Positive feedback - changes enhance
Glacier mass balance
• Difference between accumulation and ablation
• Positive mass balance - accumulation > ablation
• Negative mass balance - ablation > accumulation
• Equilibrium - ablation = accumulation
Accumulation zone
• Positive mass balance
• Origin of glacier high in the mountains where snowfall is high leads to
formation of ice
• Factors affecting growth:
o Climate - shorter summers mean less ablation and snow remains
permanent
o Further snow - gradual accumulation of snowing turning to firn,
then ice.
, o Aspect
Ablation zone
• Negative mass balance
• Snout of glacier - lower elevations have higher average temps so ice
melts
• Factors affecting decay:
o Higher summer temps - lead to negative mass balance causing
retreat
o Calving
Inputs
• Precipitation
• Thermal energy
• Potential energy
• Kinetic energy
• Melt water
• Avalanches
• Material (from deposition etc.)
Outputs
• Sediment
• Calving
• Ablation
• Sublimation
• Evaporation
• meltwater
1b) influences on glaciated landscapes
,CLIMATE:
• Wind:
o Can shape landscape through aeolian processes (wind driven
processes like erosion, deposition and transport) in particularly fine
material deposited by meltwater
• Precipitation:
o Major input (snow, rain, sleet) in glacial system
o Can be affected by latitude, altitude and seasonal variation
o High in high altitude but low in high latitude
o Higher altitudes have greater seasonal variation than higher
latitudes
o The greater seasonal variation the greater variation in mass
balance
• Temperatures:
o Temps >0ºC = higher ablation and outputs
o Greater variation in high altitudes as there is seasonal variation
o High latitudes have less temp variation but never >0ºC so despite
low precipitation ice sheets are thick
Altitude
o Even at low latitudes highest points have ice
o Temp decreases at rate of 0.6ºC/100m increase in height
Latitude
o High latitude = dry/little seasonal variation
o Contrasts to high altitudes in low latitudes as there is more seasonal
variation so dynamic valley glaciers will shape the landscape more
GEOLOGY:
• Lithology - physical/chemical composition of rocks
o Basalt - strong structure with interlocking crystals make it more
resistant to erosion
o Limestone - chemically weaker and soluble in weak acids makes it
more vulnerable to chemical weathering
• Structure - properties of individual rocks
o Jointed/permeable rock - allows water through joints and can easily
exploit joints through solution and freeze thaw processes
o Porous rocks - presence of small air spaces allows water to enter
and freeze thaw and solution can take place
o Angle of dip - where rocks incline profiles follow the angle - valleys
sides are steeper where there is horizontally bedded rock
Relief
o The steeper the relief the more potential energy due to the greater force
of gravity so the glacier will have more energy to move downslope
Aspect - direction a slope faces
o Facing away from the sun means temps will remain 0ºC for longer so less
melting will take place and they will have a positive mass balance
making them advance downslope
o The higher the mass balance the larger the erosive power the glacier has
so greater shaping of landscape
, Melt water
o Can be input/output
o Increases velocity of glacier so reaches lower altitudes quicker
1c.a) glacial ice formation
