Glacier Key Terms Flashcards
Define Ablation
The output of snow and ice from a glacier
Define Ablation Till
Till deposited from melting ice from retreating glaciers
Define Ablation Zone
Where outputs from a glacier exceed inputs
Define Abrasion
The grinding away of bedrock by fragments of rock in the ice
Define Accumulation
The input of snow and ice into a glacier by precipitation avalanches and wind
Define Accumulation Zone
Where inputs from a glacier exceed outputs
Define Active Landscape
A landscape experiencing glaciation
Define Active Layer
The top layer of permafrost that freezes in winter and thaws in summer
What is the Albedo Effect
Solar radiation that gets reflected
Define Alpine
Glacial environments found in high altitude areas
Define Avalanch
A sudden downslope movement of snow and ice
Define Basal Melting
Melting at the base of the glacier that increases the movement speed
Define Basal Slip
When pressure and friction create meltwater which lubricates the movement of the glacier
Define Calving
The breaking up of chunks of ice at the glacier snout to form icebergs when a glacier reaches a body of water
Define Crique Glacier
A small glacier in a mountain hollow that craves out a corrie
Define Compressional Flow
When reductions in a gradient force slow down casing it to thicken
Define Continous Permafrost
Where the ground is permanently frozen found in high latitude areas and is frozen until 500m below the surface
Define Cryosphere
The parts of Earth that are subjected to negative temperatures at some time in the year
Define Discontinuous Permafrost
The shallow frozen ground that thaws in summer
Define the Dynamic Equilibrium
When landforms and processes are in a state of balance
Define Englalical
Debris inside Glaciers
Define Entrainment
The process by which surface sediment is incorporated
Define Environmental Lapse Rate
The rate of atmospheric temperature decreases with altitude
Define the Equilibrium Line
Where outputs from a glacier are the same as inputs
Define Extensional Flow
When an increase in gradient causes the ice to flow faster
Define Extrusion Flow
The theory that glacier ice flows faster at depth
Define Fluvioglacial
The erosion caused by the meltwater of a glacier
Define Freeze-Thaw Weathering
When water enters a rocks joints expands by 10% due to freezing, causing the rock to slowly disintegration
Define Frost Heave
When freezing and expanding of the soil forces stones upwards
Define Glacials
Cold icehouse periods
Define Glaciers
Slow-moving bodies of ice found in polar and alpine regions
Define Glacial Mass Balance
The difference between acculamtion and ablation of snow and ice
Define Glacial Outburst Flood
A sudden release of water from a sub/proglacial lake
Define Greenhouse Conditions
Warm interglacial periods
Define Holocene
The latter epoch in the Quaternary that began 10,000 years ago
Define Ice Caps
Smaller versions of Ice Sheets in upland areas
Define Ice Fields
Ice covering an upland area that is not deep enough to cover topography
Define Ice Sheets
When ice completely covers topography
Define Ice Shelf
Large areas of floating ice on the coast
Define Icehouse Conditions
Cold glacial conditions
Define Imbricarion
Where glacial deposits are aligned overlapping each other
Define Interglacials
Warmer periods of time
Define Internal Deformation
When glacial ice courses ice crystals to deform
Define Loess
A windblown deposit of silt or clay in glacial conditions
Define the Meso Scale
Large scale landforms
Define the Mirco Scale
Small scale landforms
Define Firn
Crystalline snow in the upper part of the glacier
Define Nivation
A combination of processes that erodes the ground below a snow patch
Define Periglacial
Areas on the edges of glacial environments that don’t have a permanent layer of ice
Define Permafrost
A layer of soil that is permanently frozen
Define Piedmont Glacier
Valley glaciers that extend beyond valleys
Define Pleistocene
The first epoch of the Quaternary period occurring from 2MYA to 10,000YA
Define Plucking
When a rock is removed by water penetrating its joints
Define Polar
Glacial environments found in high altitude areas
Define Polar Glacier
The glaciers in cold polar environments
Define Pressure Melting point
The pressure that dictates when the ice melts
Define Quaternary
The time period which we are living in that started 2MYA
Define Regelation Creep
When ice melts under pressure travels around an obstacle and refreezes
Define Relict Landscape
A landscape that has experienced glacial action in the past
Define Solifcation
The downslope movement the saturated active layer under the influence of gravity
Define Sporadic Permafrost
When permafrost only covers 50% of the land
Define Stadials and Interstadial
Short term fluctuations within the icehouse/greenhouse conditions
Define Subglacial
Debris transported on beneath the glacier
