Cold Environments Flashcards
Katabatic Winds
- extremely cold winds that chill the ice
Periglacial Climate
- Covered in ice, but not all year round
- found in high altitude or high latitude
Mountain Climate
- Areas that used to be covered in ice, but are now free from snow or ice
- features still remain
Orographic Rainfall
- Rain that is produced as air is forced to rise over high ground such as a mountain barrier
- it subsequently cools, condensation occurs and precipitation is produced
Insolation
At high latitudes the heat and Ray’s from the sun have to spread out over a greater surface area, therefore it is less effective
Glacial Processes
- weathering
- transportation
- deposition
How do glaciers form?
- snowfall exceeds snowmelt for a long period of time
- the snow accumulates incrementally
- pressure increases
- changed into névé and glacier
What is a corrie?
The hollow where a glacier begins
How does a corrie form?
- ABRASION: the former surface debris which is incorporated in the glacier wears away the basin
- PLUCKING: the glacier melts, then freezes around jutting out rock, and black this rock out of the back wall (adds to abrasion)
- FREEZETHAW WEATHERING
What is a fjord?
-An inlet with sharp sides, created by glacial erosion, that is connected to the sea but is extended below sea level
How is a fjord formed?
- a glacier cuts a u-shaped valley in the surrounding bedrock
- the glacier retreats, leaving the valley behind, and the sea fills the valley floor
What is Isostatic Uplift
- sea level change as a result of a change in the height of the land
- glaciers put pressure on the land, causing the land to decrease: and the sea level to rise
- when the glaciers melt, this pressure is released and the land slowly rises: and the sea level decreases
Arêtes
- a sharp ridge cause by intense freezethaw
- formed when two neighbouring corrodes run back to back
Pyramidal Peaks
A sharp point caused by 3 or more Arêtes converging
U-shaped Valleys
- characterised by steep sides and a relatively flat bottom
- result from the channel long of ice through valleys, combining freeze-thaw, plucking and abrasion
Truncated Spurs
- a projection of land from a ridge or mountain
- Spurs are rounded areas of land which have been cut off
- formed when glaciers move through the main valley and cut off Spurs
Ribbon Lakes
- long linear lakes which fill a glaciated trough
- glacier moves over an area containing alternate bands of hard and soft bedrock
- also if a tributary glacier joins a main glacier: increase in power creates a trough, which is filled with water from a river to create a ribbon lake
Hanging Valley
- small u-shaped valley formed by a small glacier that joins and hangs above a large a large u-shaped valley formed by a larger glacier
- waterfalls can often be seen
Till
-finely grained rock flour (sand and clay)
Erratics
-large boulders foreign to the local geology which have been dumped by the ice usually on flat areas
Moraines
-lines of rock fragments which have been weathered from the valley sides above the ice and have fallen downslope onto the ice
Drumlins
- elongated hills of glacial deposits
- would have been part of the debris that was carried along and then accumulated under the ancient glacier
Eskers
- elongated ridges of coarse stratified sands and gravels
- the ridges usually meander
Kames
- irregular mounds of bedded sands and gravels arranged in a chaotic manner
- formed where a meltwater stream flowed out beneath an area of stagnant or decaying ice, into a lake dammed between the ice front and drift materials
Frost Heave
The process where water freezes in the soul and pushes the surface upwards and churns it
Ice-Lensing
The process where ice crystals in the soil
Soilfuction
- flowing soil: an accelerated form of soil creep
- in winter water freezes in the soil causing expansion of the soil and segregation of individual soil particles
- in spring ice melts and water flows downhill, it can’t infiltrate I tot he soil because of the impermeable permafrost
- as it moves over the permafrost, it carries segregated soil particles and deposits them further downslope as a soilfuction lobe
Chemical Weathering
- carbonation: low temperatures = CO2 is more soluble, thus water become acidic
- hydration: certain minerals absorb water, expand and change
Glacial Climate
- Covered in ice all year round (permanent)
- katabatic winds
