EQ1 Flashcards
Glacial period
Period of time during an ice age when glaciers advance because of colder temperatures.
Interglacial period
Period of time during an ice age when glaciers retreat because of milder temperatures.
Icehouse conditions
Very cold glacial conditions.
Greenhouse conditions
Warmer interglacial conditions.
Pleistocene
Period of time from about 2 million years ago to 11,700 years ago. During this period areas of land at higher and middle latitudes where covered with glacial lice.
Milankovitch cycle
A theory which suggests that changes in the Earths climate are caused by variations in solar radiation at the earths surface. There variations are due to cyclical changes in the geometric relationships between the Earth and Sun. It comes in three parts: axial tilt and earth wobble.
Stadials
Short term changes to conditions that lead to ice re advances.
Interstadials
Short term changes to conditions that lead to ice.
Orbital / Astronomical forcing
A process which can change the amount of energy from the sun reaching the Earth and forces climate to change as a response.
Albedo
The amount of light or radiation that is reflected by a surface such as ice.
Calving
The breaking up of the ice sheet at the glacier snout which then forms icebergs.
Thermohaline circulation.
The oceans consists almost entirely of water and salt. The density of water depends on its temperature and salinity. Any changes to this causes the water to flow (currents). Also known as ocean conveyer.
Ablation
Surface removal of ice or snow from a glacier or snowfield by melting sublimation, and/or calving.
Cirque
Landform created by glaciers, grinding an existing valley into a rounded shape with steep sides, often called a corrie or a cwm.
Ice field
Large levels area of glacial ice found covering a large expanse of land. Similar in size to an ice cap but does not have a dome shape.
Cryosphere
The frozen water part of the Earth system.
Nivation
Process where snow patches initiate erosion through physical weathering, meltwater flow and gelifluction.
Solifluction
Form of mass movement in environments that experience freeze-thaw action. It is characterised by the slow movement of soil material downslope and the formation of lobe-shaped featured.
Permafrost active layer
The top level of soil of permafrost that thaws and freezes during summer and winter.
Continuous permafrost
Form of permafrost that exist across a landscape as an unbroken layer.
Discontinuous permafrost
Form of permafrost that contains numerous scattered pockets of unfrozen ground.
Sporadic permafrost
Form of permafrost that exists as small islands of frozen ground in otherwise unfrozen soil and sediments.
