Glaciation Flashcards
(22 cards)
What is permafrost ?
Where a layer of soil, sediment or rock below the ground surface remains almost permanent frozen
What is a fragile environment?
An environment susceptible to change and easily damaged
How long was the Pleistocene period ?
Approx 2 million years
When did the Pleistocene period end ?
11,700 years ago
What is the name given to the period of cooling between 1550 to 1850 which occurred after the medieval warm period?
The little Ice age
What is the word to describe periods of cold ice advances?
Stadials
Define an interstadial period
Periods of warm ice retreat
Which epoch are we currently within?
The Holocene
Define the cryosphere
The frozen part of the earths hydrological system
What is the albedo effect?
The ability of snow and ice to reflect heat (solar radiation) back
off the earths surface
What are ice sheets ?
Vast expanses of ice
Often over 1km thick
What are ice shelves?
Where ice sheet margins extend out to sea
What are ice caps?
Small masses of ice associated with mountain ranges
What are ice fields?
Areas of ice less than 50,000km squared
Extensive regions of interconnected valley glaciers
What is the name of high mountain peaks that rise above ice fields?
Nunataks
What is the name given to the temperature at which ice is in the verge of melting ?
Pressure melting point
What is a polar region and an example of where one is located?
Areas of permanent ice and of high latitude
Ex - Central Greenland
What is a periglacial region and what is an example or one ?
Areas at the edge of permanent ice
Characterised by permafrost
Ex- Russia
What is an alpine region and where would you find one ?
High altitude regions resulting in cold conditions
Glaciers are often found here
Ex- the Himalayas
What is a glacial environment and what is an example of one ?
Environments found at the edges of ice sheets and in the higher mountain regions
Ex- the Southern Andes
What process can be sporadic, continuous or discontinuous depending on temperature ?
Permafrost
Define the active layer ! (Permafrost )
A saturated and mobile layer above permanently frozen material that thaws and freezes regularly and seasonally
