GCE O/L Geography key terms

The theory that Earth's outer shell is broken into large rigid slabs that move slowly over the softer layer beneath, causing earthquakes, volcanoes and mountain building where they meet.

A place where two tectonic plates move towards each other, producing compression, earthquakes and often a deep ocean trench or a mountain chain along the collision zone.

The process in which a denser oceanic plate sinks beneath a lighter plate into the mantle, melting at depth and feeding magma upwards to form volcanoes and island arcs.

A highland formed when thick layers of rock are squeezed sideways by plate collision and buckle into arched folds, as in the Himalayas.

The breakdown of rock in place by rain, frost, heat, plant roots or chemical reaction, without the broken material being carried away.

The wearing away of rock and soil by moving agents such as running water, waves, ice or wind, together with the transport of the loosened material to another place.

The laying down of eroded material when a transporting agent loses energy, for example where a river slows on entering the sea or where wind drops sand.

A low, fan-shaped area of new land built where a river deposits silt as its flow slows on reaching a lake or the sea.

The continuous movement of water between ocean, atmosphere and land through evaporation, condensation, precipitation, runoff and storage in soil, rivers and groundwater.

The change of liquid water into vapour at the surface of oceans, lakes and soil when it gains heat energy, usually driven by sunshine and wind.

Water falling from clouds to the ground as rain, snow, sleet or hail, produced when moist air cools and its vapour condenses.

The average pattern of weather in a place over many years, including typical temperatures, rainfall amounts and seasons, rather than day-to-day conditions.

The state of the atmosphere at a particular place and moment, described by temperature, cloud, wind, humidity and rainfall.

A dry area on the sheltered side of a mountain range, where descending air has already lost its moisture on the windward slopes.

A community of living things together with the non-living surroundings they depend on, such as a forest, coral reef or pond, linked by flows of energy and nutrients.

A sequence showing how energy passes from plants to plant-eaters and then to predators, each organism feeding on the one before it.

The large-scale clearing of forest for timber, farming or settlement, which removes habitats, exposes soil to erosion and reduces local rainfall.

The number of live births per 1,000 people in a population in one year, used to compare how quickly populations are growing.

The number of deaths per 1,000 people in a population in one year, influenced strongly by healthcare, diet, sanitation and age structure.

A pair of bar graphs showing the number of males and females in each age group, revealing whether a population is young and growing or ageing.

A negative condition in a home area, such as unemployment, war or poor housing, that encourages people to leave for somewhere else.

An attractive feature of a destination area, such as jobs, schooling or safety, that draws migrants towards it.

The rising share of a country's people living in towns and cities, usually driven by rural-to-urban migration and natural growth in cities.

An area of self-built housing on land occupied without legal title, often lacking piped water, sewers and paved roads, common in rapidly growing cities.

A part of a town or city where one main activity dominates, such as the central business district, industry, or residential suburbs.

The commercial core of a city, marked by tall offices, shops, banks and high land values, usually at the focus of transport routes.

Farming that produces mainly food for the farmer's own household, using little bought input and leaving little or no surplus for sale.

Farming carried out mainly to sell produce for profit, often with larger fields, machinery, hired labour and purchased seed and fertiliser.

A system that obtains high output from a small area through heavy use of labour, capital, fertiliser or irrigation, such as market gardening or battery poultry.

Energy from sources that are naturally replaced within a human lifetime, such as sunlight, wind, flowing water, tides and plant material.

A natural material such as coal, oil, gas or metal ore that formed over millions of years and is used up faster than it can be replaced.

Meeting present needs for resources and growth without damaging the environment or using up resources that future generations will require.

A line on a map joining points of equal height above sea level, so that closely spaced lines show steep ground and widely spaced lines show gentle slopes.

The relationship between a distance on a map and the real distance it represents, shown as a ratio, a statement or a divided bar.

A side-view diagram drawn from a map along a chosen line, plotting height against distance to show the shape of the land.

The whole area of land drained by a river and its tributaries, bounded by a watershed of higher ground.

A testable statement predicting a relationship between two variables, which fieldwork data is collected to support or reject.

Selecting a limited number of sites or people to measure or question so that results represent a larger area or group within available time.

Geographical investigation carried out outdoors, involving planning, collecting primary data at sites, recording it accurately and then presenting and interpreting the results.