Geography Key Words

Milankovitch Cycles

The collective name for long term, cyclical changes in the earth’s orbit and orientation, affecting the level of solar radiation that reaches the earth over thousands over years.

Eccentricity

The change in the orbit of the earth from nearly circular to more eliptical over a period of 100,000 years due to the gravitational pull of other planets (mainly Jupiter and Saturn) and the more eliptical the orbit, the greater the seasonal difference.

Obliquity

The change in the tilt of the Earth’s axis from 22.1 to 24.5 degrees over a period of 41,000 years and the greater the tilt, the intenser the seasons.

Precession

The wobble of the Earth’s axis over a period of 26,000 years due to the gravitational pull of the Sun and the Moon, changing the timing of the seasons.

Adaptation

actions that aim to reduce/cope with the effects of global warming.

Mitigation

Actions that reduce the level of greenhouse gases in the environment with the aim of stopping/reversing global warming.

Globalisation

The process by which goods, money, services, cultures and people have spread around the world, connecting more places than ever before.

A superpower

A country or nation with a dominant position in international relations, categorised by their unparalleled ability to exert control or project power on a global level.

Neocolonialism

The indirect control over LEDCs by more developed countries usually through economic or political power.

Albedo Effect

The reflectivity of a surface.

Glacials

The cooler periods of an ice age when large areas of the earth were covered by ice and glaciers expanded.

Interglacials

The warmer periods of an ice age when ice sheet melted, sea levels rise and climate becomes warmer.

Proxy Measurement

An indirect indicator of a variable that is difficult to measure directly.

A dam

A structure built across a stream/river/watercourse to hold back and control water flow.

Viscosity

The resistance of a fluid to flow

Magma

The molten rock found beneath the earths surface eg store in a magma chamber

Lava

The molten rock that has reached the earths surface ince it has been erupted

A hotspot

An area of the crust that is particularly thin and there is a build up if magma underneath

Tectonic Plates

Large slabs of the earth’s crust that floats above the mantle and have an important role in causing natural hazards.

Natural hazards

natural event such as a volcano that has the potential to cause loss of human life, damage to infrastructure or injury.

Earthquakes

the sudden shaking and shock waves felt on the Earth’s surface caused by a sudden release of energy from the Earth’s crust

Magnitude

a measure of the size and strength of an earthquake

Seisometer

an instrument for recording the vibrations during an earthquake

Aftershock

smaller earthquakes that follow a larger earthquake, in the same area of the main shock

Fault

A fracture between two slabs of rock (tectonic plates) that enable them to move

Soft Power

influence on another country through economic or cultural persuasion

Focus

the centre of an earthquake in the crust where it origintates, it takes place along the fault and is where pressure is released.

Seismic Waves

These are the waves of energy released during an earthquake that radiate outwards and some may reach the surface.

Epicentre

the point on the earth’s surface directly above the focus. This area experiences the strongest shaking and more severe damage

Chloropleth Map

map that uses colours or shading to represent the different ranges of a particular variable across the area.