GTLE Geography flashcards
GTLE Geography · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Subduction zone
- A convergent boundary where denser oceanic lithosphere descends beneath another plate, generating deep earthquakes, explosive volcanoes, trenches, and island arcs.
- Fold mountains
- High mountain ranges formed where thick sedimentary sequences are compressed and uplifted at a convergent plate boundary, producing anticlines and synclines.
- Shield volcano
- A broad, gently sloping volcano built by fluid, low-silica basaltic lava that flows far before solidifying, typical of hotspots and divergent boundaries.
- Composite cone
- A steep-sided volcano built from alternating layers of viscous lava and ash, typical of subduction zones where high-silica magma produces explosive eruptions.
- Freeze-thaw weathering
- Mechanical weathering in which water enters rock joints, freezes, expands, and prises the rock apart, dominant in cold climates with frequent temperature fluctuations around freezing.
- Carbonation
- Chemical weathering in which weakly acidic rainwater dissolves calcium carbonate in limestone and chalk, forming caves, stalactites, and swallow holes in wet regions.
- Hydraulic action
- River or coastal erosion caused by the force of moving water compressing air in cracks, weakening and eventually breaking up rock and cliff faces.
- Longshore drift
- The zigzag movement of sediment along a coast caused by waves approaching at an angle, building spits, bars, and tombolos where the coastline changes direction.
- Storm hydrograph lag time
- The delay between peak rainfall and peak river discharge; it shortens with impermeable rock, steep slopes, bare soil, and urban surfaces, raising flood risk.
- Meander formation
- A river curve produced by faster flow eroding the outer bank and slower flow depositing on the inner bank, with cut-offs forming oxbow lakes on the floodplain.
- Glacial trough
- A U-shaped valley eroded by ice, with steep sides, a flat floor, truncated spurs, and hanging valleys where tributary glaciers joined the main glacier.
- Drumlin
- A streamlined mound of glacial till shaped beneath moving ice, with a blunt end indicating the up-ice direction and a tapering end indicating ice flow.
- Outwash plain
- A flat area of sorted, rounded sediment deposited by meltwater streams beyond a glacier's terminus, in contrast to unsorted till deposited directly by ice.
- Population pyramid
- A graph showing population by age and sex; a wide base indicates high birth rates and future growth, while a narrow base with a wide top indicates ageing.
- Dependency ratio
- The proportion of a population outside working age relative to those of working age, indicating the burden on services, pensions, and the labour force.
- Natural increase
- Population growth calculated as birth rate minus death rate per thousand people, excluding the effect of migration into or out of an area.
- Counter-urbanisation
- The movement of people from cities to rural areas, driven by housing costs, congestion, and lifestyle preferences, often increasing commuting and rural service demand.
- Settlement hierarchy
- An ordering of settlements by population size and the range and number of services they provide, with higher-order services found only in larger centres.
- Central business district
- The zone of a city with the highest land values and accessibility, dominated by retail, offices, and transport hubs, and with few permanent residents.
- Urban heat island
- The tendency of cities to be warmer than surrounding countryside because building materials store heat and vegetation and evaporation are reduced.
- Desertification
- Land degradation in drylands caused by overgrazing, overcultivation, deforestation, and drought, reducing productivity and biodiversity, and distinct from drought itself.
- Leaching
- The downward movement of dissolved nutrients through soil by rainwater, dominant in humid climates and producing nutrient-poor, often acidic soils.
- Salinisation
- The accumulation of salts in soil through evaporation of irrigation water in dry climates, reducing fertility and crop yields and often caused by poor drainage.
- Relief rainfall
- Rainfall produced when moist air is forced over high ground, cooling and condensing on the windward slope and leaving a drier rain shadow to leeward.
- Hadley cell
- A circulation cell in which moist air rises at the equator and sinks dry air near 30 degrees latitude, producing equatorial rainforests and subtropical deserts.
- Human Development Index
- A composite development measure combining income per capita, life expectancy, and education, giving a broader picture than GDP per capita alone.
- Sustainable development
- Development that meets present needs without compromising future generations, balancing economic, social, and environmental objectives in policy and practice.
- Mitigation versus adaptation
- Mitigation reduces greenhouse gas emissions or enhances sinks, such as afforestation; adaptation adjusts to expected impacts, such as flood defences and drought-resistant crops.
- Hazard risk
- The likelihood of harm from a hazard, shaped by exposure and vulnerability, so the same hazard can cause very different losses in different places.
- Six-figure grid reference
- A map location given by easting then northing, each to three digits, locating a point within a grid square rather than the square itself.
- Contour interval
- The vertical height difference between adjacent contour lines; closely spaced contours indicate steep slopes and widely spaced contours indicate gentle slopes.
- Map scale
- The ratio of map distance to real distance, so a 1:50,000 map means one centimetre represents 0.5 kilometres on the ground.