Geography- full glossary

Cinder/pyroclastic cone

a steep-sided volcano consisting of loose fragments of lava and volcanic ash

Conservative margin

an area where two tectonic plates slide past each other

Convergent/collision margin

where two pieces of continental crust move towards each other

Convergent/destructive margin

an area where tectonic plates containing oceanic crust move towards those containing continental crust

Core

the extremely hot centre of the Earth

Crust

the top layer of the Earth; it can be either continental or oceanic

Divergent/constructive margin

where two tectonic plates move away from each other

Epicentre

point on the Earth’s surface directly above where an earthquake occurs

Focus

the point within the Earth’s crust where an earthquake originates

Fold mountains

mountains formed by the squeezing of rock at converging plate boundaries

Lahar

highly dangerous, fast-flowing mixture of rainwater and volcanic materials

Liquefaction

the process when soil behaves like liquid after an earthquake

Lithosphere

the outermost shell of the Earth consisting of the crust and top part of the mantle

Magma

liquid rock found beneath the Earth’s crust

Magnitude

the strength of an earthquake

Mantle

the part of the Earth between the core and the crust

Mantle plume

a column of hot, molten rock which rises from the mantle to the Earth’s crust

Plate boundaries (margins)

the edges of tectonic plates

Pyroclastic flow

flow of materials such as ash ejected during a volcanic eruption

Sea-floor spreading

the bottom of the ocean growing wider at a constructive margin

Seismic wave

a wave of energy travelling through the Earth’s surface after an earthquake

Seismograph (seismometer)

a machine used to measure the strength of an earthquake

Shield volcano

a low gently-sloping volcano formed from thin, runny lava and frequent gentle eruptions

Strato-volcano

also known as a composite volcano, made up of alternate ash and lava layers and often has violent eruptions

Subduction zone

where oceanic crust is forced under continental crust

Tectonic plates

the Earth’s crust divided into large pieces called plates

Climate

average weather conditions over a period of at least 30 years

Climate change

changes to global climate and weather patterns caused by the increase in greenhouse gases

Deforestation

the removal of tree cover in an area for farming or other activities

Fossil fuels

energy resources such as oil, gas and coal

Greenhouse gases

gases in the atmosphere that act like a blanket and reflect heat

Migration

the movement of people from one place to live in another

Milankovitch cycles

changes in the Earth’s movements that affect climate over geological timescales

Net zero

when greenhouse gases produced by human activity are negated by methods used to remove them from the atmosphere or stop using them

Photosynthesis

the process where plants convert carbon dioxide into oxygen

Renewable energy

sources of power that can be used repeatedly

Solar power

power from the Sun

Sustainable

something that can be used on a long-term basis with little effect on the environment

Weather

short-term atmospheric conditions including temperature, cloud cover, precipitation, wind direction and speed

Anti-natalist policies

policies designed to reduce the fertility rate

Asylum seekers

migrants who want to be recognised as refugees but are still waiting to find out if their host country will accept them

Birth rate

the number of live births per 1000 people

Census

an official count of all people living in a place at one specific time

Cohort

a group of people born within a certain time period

Country of origin

the country where migrants are coming from

Death rate

the number of deaths per 1000 people

Demographic(s)

the characteristics of a population, for example age, gender, ethnicity

Dependency ratio

a measure of the proportion of people younger than 15 or older than 64 compared to the working-age population

Dependent group

sections of the population that rely on the working-age population for support

Destination country

the country where migrants are moving to

Diaspora

the spread of people from their original country to other countries around the world

Economic migrants

people who move to find a better life for themselves and their families

Emigration

when a person leaves their own country to live in another country

Fertility rate

a measure of the number of children per woman in a population

Freedom of movement

policies allowing people to travel, live and work in different countries with minimal restrictions

Host country

nations that receive migrants

Immigration

when a person moves into a different country to live there permanently or temporarily

Infant mortality rate

the number of babies that do not survive to age one per 1000 live births

Irregular migrants

economic migrants who enter a host country unofficially without following immigration procedures

Integration schemes

programmes and policies designed to help immigrants adapt and participate in their host country

Life expectancy

the average number of years a person is expected to live

Migrants

individuals who move from one place to live in another

Natural increase

the difference between the number of births and deaths over a period of time

Net migration

the total number of immigrants minus the number of emigrants

Points-based systems

immigration policies selecting migrants by awarding points for factors like age, education and language skills

Population

the total number of individuals living in a particular area or region

Population pyramid

a way of presenting the age and sex structure of a population

Population structure

the composition of a population, for example age and sex distribution

Pro-natalist policies

policies designed to increase the fertility rate

Pull factors

factors encouraging migration by attracting people to a place

Push factors

factors encouraging migration by pushing people away from a place

Refugees

people forced to leave their country to escape war, persecution or natural disaster

Remittances

money migrants send back to their home country

Rural-urban migration

movement of people from the countryside to towns and cities

Sanitation

systems that improve health by removing waste that can spread disease

Soil exhaustion

when soil can no longer support plant life

Trend

a pattern or development identified in data over time

Affordable housing

housing accessible to people with low to moderate incomes

Counter urbanisation

movement of people from urban areas to rural or suburban areas

Expatriates

immigrants living in another country by choice

Formal sectors

parts of the economy regulated by the government including taxes

Informal sectors

economic activities operating outside government regulation

Informal settlements

areas where housing is built without formal planning or government regulation

Infrastructure

the basic facilities and systems serving a place

Load-shedding

deliberate shutdown of electric power to prevent overloading of the grid

Megacities

cities with populations over 10 million people

Meta-cities

urban areas with populations exceeding 20 million people

Natural increase

population growth occurring when birth rate exceeds death rate

Rural

areas of low population density and open spaces

Rush hours

periods during the day when traffic congestion is at its peak

Sanitation

provision of clean water, proper waste disposal and sewage treatment

Soil erosion

removal of the top layer of soil by wind or water

Streetscape

the appearance of buildings and other elements making up a street

Suburbanised

the process by which urban areas extend outwards

Sustainability

maintaining quality of life without damaging the environment or future generations

Sustainable transport

transport systems with minimal environmental impact

Upward social mobility

ability of individuals or groups to improve socio-economic status