Glaciation Flashcards
Névé
Low density granular snow consisting of ice crystals
Sensible heat
The amount of heat energy that occurs when an object is heated. When an object’s temp falls, the heat removed is also called sensible heat
Sublimation
Solid straight to gas e.g ice to water vapour
Accumulation
The addition of snow or ice to a glacier
Ablation
The natural removal of snow or ice to a glacier
Accumulation zone
The area of net gain in a glacier
Ablation zone
The area of net loss in a glacier
Zone of equilibrium
Net gain of snow = net loss of snow
Paleoclimatic
Climatic conditions in the geological past or reconstructed from a direct or indirect data source
Pleistocene era
The first epoch of the quaternary period
Altitude
The height above sea level
Latitude
The distance north or south of the equator
Permafrost
Areas of permanently frozen ground
Thermohaline system
Part of the ocean circulation, caused by differences in water density, temp and salinity
Ice lenses
Formed when moisture in the soil accumulates under rocks, they then freeze and push the rocks up in a process called frost heave
Glacial period
A time period when ice masses develop and advance into lower latitude
Interglacial period
A time period when glaciers retreat to the polar regions
Internal deformation
Small scale movement of ice due to gravity. The ice crystals become unaligned
Crevasse
Large deep fractures in a glacier, caused by extensional flow
Basal sliding
The large scale movement of ice due to glacial melt water, only in warm based glaciers
Pressure melting point
The temperature at which ice melts under pressure, can occur below freezing
Seracs
Steep faults on the surface of a glacier
Extensional flow
Ice is moving faster at the front of the glacier so the ice is stretched, causing crevasses
Compressional flow
The ice behind is moving faster than the front so a build up of ice occurs
Abrasion
Rock on rock action wearing away the sides and bottom of a glacier emg rocks in a glacier on the bedrock below
Plucking
When ice freezes to the rock below and moves, pulling it out of the ground
Rotational slip
When a glacier begins to rotate with mass, this causes erosion on the sides and back wall
