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Mackinder Heartland Theory 
A body of work that suggests that whomever controls the largest geographical area of land (such as Eastern Europe) is likely to reign over the peripheral areas around it.

A combination of molten (or semi-molten) rock and gas found beneath the Earth's surface.

An expression of the total energy released by an earthquake.

A treatable parasitic disease which is spread through the contamination of blood from a bite from a mosquito.

A state whereby a person or population suffers ill health as a result of having a nutritionally imbalanced diet.

Of the view that as population numbers increase the world's ability to grow enough food to meet their demands will decrease.

Managed Realignment / Retreat 
A measure whereby coastal defences to erosion are removed and areas are allowed to flood, often in order to preserve more valuable areas further down the coast.

Various types of trees that grow in saline conditions, often on the beach and shore line.

The middle layer of the Earth lying between the crust and core.

Manual Labour 
Work that involves the use of large numbers of workers with little help from machinery.

The process by which raw materials are made into goods which can be bought and sold.

Assembly plants found on the USA / Mexico border to which foreign materials and parts are shipped and from which the finished product is returned to the original market.

A social process that leads to some social groups being separated from others.

Marine Pollution 
The build up of liquid chemicals such as oil and foreign objects such as plastics in the seas and oceans.

The demand for certain goods as well as the place where they are most likely to be sold.

Market Gardening 
The intensive production of fruit, vegetables and flowers.

Mass Movement 
The downslope movement of rock fragments and soil under the influence of gravity. 

Maternal Mortality Rate 
The number of women who die from pregnancy-related illnesses while pregnant or within forty two days of giving birth (per 100,000 live births).

The process by which a country adopts the characteristics of a fast food culture such as efficiency, calculability, predictability and control.

A winding curve - with a sinuosity of above 1.5 -  in the course of a river.

The increased use of machinery to support working practices.

Medial Moraine 
A ridge of unconsolidated debris that runs down the centre of a valley floor, formed when two glaciers meet and the debris on the edges of the adjacent valley sides converges.

A city or city region whose population is at least 10 million

A large network of connected areas that share economic values, topographic landscapes or environmental systems.

Mercalli Scale  
A measurement of the intensity of an earthquake by the damage that it does.

A cylindrical map projection where the position of the continents is thought to be accurate but their relative size is inaccurate.

A city or city region whose population is at least 20 million.

Metamorphic Rock 
Rock that has been changed from its original form by heat or pressure beneath the surface of the Earth.

The loan of small amounts of money to very poor households at commercial rates.

Micro-Finance Scheme 
Finance services run by and for people with low incomes who do not have access to the banks and traditional loan services.

The movement of people in or out of a region or country.

Milankovitch Cycles 
The three variations in the orbit of the Earth around the Sun which cause variations in the amount of solar energy reaching the Earth.

Millennium Development Goals 
A set of targets that aimed to reduce different aspects of poverty worldwide between 2000 and 2015.

A site where valuable minerals or materials are extracted from the earth.

Actions that try to reduce the severity of a hazard by targeting its key processes.

Mixed Farming 
A system of farming that mixes arable farming with the raising of livestock.

Modernisation Theory (Rostow's Model) 
A development theory that suggests that countries must go through set and sequential stages of technological development before becoming modern societies.

A term used to describe the current modern era.

Moment Magnitude Scale
A successor to the Richter scale used by seismologists to compare the energy released by especially large earthquakes.

Farming where only one type of crop is grown on a large scale.

The season experienced typically in south east Asia where heavy rain falls with predictable frequency.

A seasonal change in the direction of the prevailing wind which influences weather patterns, bringing extended periods of rainfall to some tropical regions.

Layers of rock and soil debris that are deposited by a glacier as it moves through a valley.

A vertical crevasse that extends from the glacier surface towards the bed, carrying meltwater.

The point and place from which a river reaches the sea.

A relatively slow mass movement of softened debris lubricated by melting ice and snow, or by heavy rain.

Multilateral Aid
 Aid that is provided by a group of countries or an organisation that represents multiple countries.

Multiplier Effect
 A process whereby one economic change sets in motion a sequence of events that result in economic decline or growth.

Connected to the administration that runs a town or a region.

National Park
 Areas of the UK that are protected by the Government as a result of their beauty, wildlife and cultural heritage.

Changing something from private to state ownership or control.

A political system which identifies most strongly with being attached to one's country.

Natural Change 
The birth rate minus the death rate of a population.

Natural Disaster 
A naturally occurring event that has already caused huge harm to people and / or the environment.

Natural Hazard 
A naturally occurring event that has the potential to cause harm to people and / or the environment.

Natural Population Growth 
A growth in population that has come about by women citizens giving birth rather than through migration.

Natural Resource  
A property of the physical environment - such as minerals or natural vegetation - which humans can use to satisfy their needs; may be classified as renewable or non-renewable.

Natural Resources 
A naturally occurring substance that can be used in its own right or made into something else.

The continued influence of a developed country on a developing country long after the latter has officially become independent of the former.

A movement which puts the economic governance and decision-making of a scheme into the hands of private enterprise or individual groups of people.

Net Migration 
The total number of people immigrating into a country or region minus the total number of people emigrating from that country or region.

Net Primary Productivity 
The amount of energy which primary producers can pass on to the second trophic levels, representing the amount of CO2 taken in by a plant minus the CO2 it emits during respiration. 

New International Division of Labour 
A spatial division of labour that occurs across national boundaries where workers for a company are not centred in one country.

Newly Industrialised Country (NIC) 
A country that has experienced a rapid breakthrough into manufacturing and export-led economic growth.

The particular place and position a species occupies within an ecosystem according to its breeding and feeding needs.

Nomadic Pastoralists 
Farmers who move from place to place with their cattle in order to make best use of seasonal grazing.

Non-Government Organisation (NGO) 
An organisation or body that operates in a not-for-profit and apolitical fashion.

Non-Renewable Energy  
A finite energy source which cannot be restored within human lifetimes after use, such as fossil fuels.

North American Free Trade Agreement (NAFTA) 
An agreement made between the USA, Canada and Mexico allowing free trade between the countries.

Nuclear Power  
A type of energy that is harnessed from uranium through an atomic reaction whereby atoms are split and energy released.

Nucleated Settlement  
A settlement that has historically formed around a single central point such as a market square or a river crossing point.

A chemical substance which provides nourishment  for animals or plants.

Ocean Acidification 
The slow increase in pH of the oceans associated with the absorption of carbon dioxide.

Oceanic Crust  
The thinner, but denser portion of the outer, rigid part of the Earth which underlies the ocean.

Oceanic Ridge  
An underwater mountain range developed at a section of oceanic crust where magma rises up through a cracking and widening ridge.

Oceanic Trench  
Long, narrow and deep depressions on the bottom of the ocean floor, typically formed when one tectonic plates sub ducts under another.

Off Piste 
Skiing that takes place in unmarked or uncontrolled areas away from the main ski runs.

Oil Sands 
Porous sand at or near the Earth's surface which contains viscous hydrocarbons such as bitumen.

A measure from one to eight of the extent of cloud cover shown on synoptic chart.

Referring to living matter or once living matter.

Organic Farming 
Agriculture that does not use any chemical intervention (such as fertilisers or pesticides) to strengthen the quality or quantity of a harvest.

Organisation of Petroleum Exporting Countries (OPEC) 
A cartel of countries which works to protect the price of oil  by storing reserves and monitoring the international market.

Orographic Lifting  
The process that occur when an air mass is forced to rise from a low elevation to a higher one in order to pass over higher terrain.

Orographic Rainfall / Relief Rainfall  
Rainfall that forms when moisture-laden air masses are forced to rise over high ground, which cools them and begins the condensation process.

Receiving goods or services from an outside supplier.

Removing fish from the sea faster than they can naturally replenish themselves.

The over use of the land for grazing by herds, such that denudation of the landscape occurs.

Overland Flow 
The flow of water horizontally over the surface of the land, usually towards a channel.

A state where there is too great a population for a given area or set of resources to support.

Overseas Territories (British) 
Parts of the UK that are not found in its immediate waters, such as the Falkland Islands and Bermuda.

Ox-Bow Lake 
A horseshoe-shaped lake once part of (and now positioned alongside) a meandering river, created by the erosion of the river through the narrow stretch of land between the joins of the river curve.