A Flashcards
Ablation
The net loss of water from a glacier through melting, calving, evaporation, sublimation or wind transport. Is dominant to accumulation over space and time when the glacier enters warmer conditions.
Abiotic
Literally not from living things. In physical geography, used to describe non-living components of an environment such as rock or water.
Abrasion
Degradation of the land through the scouring action of materials being carried by an agent of erosion. Rates vary according to amount of material carried, energy of the agent and hardness of materials involved.
Absolute humidity
The amount of water vapour in the air in grams per cubic metre.
Absorption
The absorbing of insolation to solids, liquids and gases on the surface and in the atmosphere.
Abyssal plain
Large, relatively flat areas of ocean floor found at 5,000-6,000m below sea level. If sediments are discharged from a river and deposit relatively quickly onto the plain they may form an abyssal fan.
Accessibility
The level of difficulty associated with getting to a location or feature within a larger area measured in distance, time and / or cost.
Accretion
Growth of a natural feature by enlargement due to the addition of more of the same material.
Accumulation
The net gain in ice mass by precipitation of snow, arrival of snow from avalanche, arrival of snow by wind transport or refreezing of melt water. It is dominant to ablation over space and time when the glacier enters colder conditions.
Acidification
The increase in acidity in an environment due to the development of a particular biome or due to human pollution causing unnaturally high levels of acid rain.
Acid lava
Lavas containing high percentage of silica. Tend to have high melting points and to be highly viscous.
Acidophilous
An organism which prefers acid conditions.
Acid rain
Refers to the unnatural increase, through human pollution, in the acidity of water precipitation. Most commonly sulphuric and nitric acids formed from by-products of fossil-fuel burning and metal smelting.
Acquired immune deficiency syndrome
A fatal syndrome caused by HIV. Main characteristic is a greatly reduced ability of the body to fight infection. Victims usually die from other illnesses they can no longer fight, rather than aids itself, which can lead to underreporting.
Acrotelm
The upper layer of peat deposits.
Active layer
The upper few metres of soil in a periglacial area which undergoes thawing in summer and is prone to mass movement relative to the permafrost layer below.
Adiabatic
Change in temperature due to expansion or contraction of a parcel of air which thus changes the pressure and therefore the temperature. No heat transfer between the air parcel and the surrounding air.
Adret slope
A south-facing slope.
Adsorption
Physical or chemical bonding of solid particles with liquids or gases.
Advection
Horizontal transfer of heat by a horizontally moving air mass.
Aeolian
Literally ‘of the wind’. Refers to transportation, erosion and deposition by wind action.
Afforestation
Planting of trees on previously un-wooded land.
Aftershock
Ground tremors occurring after a major earthquake but associated with the same focus point.
Agent of erosion
The direct source of movement that can cause erosion through the transfer of energy or transport of rock material: water (rivers and waves), wind and ice.
Agglomeration
The grouping together of businesses in the same area to minimize costs through linkages.
Aggradation
Deposition of load within river channels.
Agribusiness
Corporations organized to provide vertical linkages both below and above the farm itself.
Agriculture
The science, art, and business of cultivating the soil, producing crops, and raising livestock; farming.
Agricultural chain
Every step in the process(es) that lead to the consumption of food.
Agricultural revolution
A period of fundamental changes to agricultural systems which tend to concentrate land and production into fewer hands while increasing yields. Changes may be organizational and technological.
Aid
Transfer of resources from a donor to a recipient. May be undertaken at a variety of scales usually under the following conditions:
(1) Bilaterally between national governments. The donor will usually attach specific conditions both economic and political.
(2) Multilaterally where donors contribute to an agency (e.g. World Bank) which then distributes to recipients again imposing political and economic conditions but at a system level.
(3) Voluntary aid - charitable, non-governmental organizations (NGOs) generate income from collection campaigns in the donor country for use in smaller-scale often community level schemes in recipient countries. Usually not tied.
