Tectonics, Rivers, and Coasts Vocabulary

Flashcards covering key vocabulary from the lecture notes on tectonics, rivers, and coasts.

Constructive Plate Margin

Plates move apart, causing magma to rise and form new oceanic crust, resulting in underwater volcanoes and islands.

Iceland

An example of a large landmass formed by constructive plate margins.

Himalayas

Fold mountains formed by the collision of the Eurasian and Indian plates.

Conservative Plate Margin

Plates slide past each other, causing tension to build up and resulting in earthquakes, exemplified by the San Andreas Fault.

Destructive Plate Margin

An oceanic plate is pushed underneath a continental plate, forming a deep-sea trench, and causing the oceanic crust to melt into magma, leading to volcanoes.

Collision Plate Margin

Two continental plates move towards each other, neither can be subducted, crust crumples upwards to form fold mountains.

Slip-off slope

A gently-sloping area formed on the inside of a river meander.

Stack

A pillar of rock which stands in the sea.

Transportation

The movement of eroded material.

Reservoir

A lake behind a dam.

River cliff

A steep, undercut area on the outside of a river meander.

Saltation

The transport of sand in a hopping fashion in water or air.

Solution

The transport of a soluble load in water.

Source

The beginning of a river.

Suspension

The transport of silt in water.

Tributary

A river joining a larger river.

Watershed

The area of high land separating one drainage basin from another.

Weathering

The breaking down of rocks, in situ, by the weather, plants and animals.

Swash

An incoming coastal wave.

Spit

An extended beach which grows by deposition across a bay or river mouth.

Traction

The transport of boulders in a rolling motion in water.

Upper Course

The section of a river near its source, dominated by the processes of erosion.

Waterfall

A point on a river where water falls vertically.

Collision boundary

Where continental plates collide.

Conservative boundary

Where two tectonic plates slide past each other, but where crust is neither formed nor destroyed.

Constructive boundary

Where two tectonic plates move apart from each other and new crust is formed.

Core

The center of the Earth.

Crust

The thin outer layer of solid rock around the Earth's surface.

Convection current

Heated plumes of magma that create crustal plate movement.

Destructive boundary

Where an oceanic plate slides underneath a continental plate or another oceanic plate.

Dormant

Inactive

Earthquake

A sudden and violent shaking of the ground caused by tectonic movements.

Epicentre

The point on the Earth's surface directly above the focus of an earthquake.

Extinct

No longer active (of volcanoes)

Fault

A line of weakness in rock.

Focus

The point underground where the energy of an earthquake is released.

Foreshock

A small earthquake before a large one.

Geothermal energy

Heat and electricity produced from hot, underground water.

Igneous

Rock made from solidified lava or magma.

Lahar

A product of volcanic eruptions composed of a mixture of ash and water.

Lava

Molten rock at the Earth's surface.

Magma

Molten rock beneath the Earth's crust.

Mantle

The semi-solid mass of rock beneath the Earth's crust.

Plate boundary

The point where two tectonic plates meet.

Plate tectonics

The theory explaining how the Earth's crust is able to move.

Pyroclastic flow

A cloud of superheated gas and ash ejected from a volcano.

Sedimentary rock

Layered rock formed by deposition of sediments.

Seismic wave

A shock wave produced by earthquakes.

Seismometer

A sensitive instrument used to measure earthquakes.

Subduction zone

The downward movement of crust at a destructive plate boundary.

Tectonic plate

A large, rigid section of the Earth's crust.

Tsunami

A sea wave caused by earthquakes and volcanic eruptions.

Volcano

A mountainous vent or fissure in the earth's crust that emits lava and other igneous products.

Volcanic bomb

Lava exploded into the air which solidifies as it falls.

Abrasion

A type of erosion involving rock particles being scraped against, and wearing away, the surface of other rocks.

Arch

A coastal feature created by the erosion of back-to-back caves.

Attrition

A type of erosion involving rock fragments being ground together to become smaller, smoother and rounder.

Backwash

The outgoing water from a coastal wave.

Bay

An area of sea between two headlands.

Beach

Material which the sea deposits on the coast.

Braiding

A river feature consisting of islands of sediment deposited in the river channel in its middle course.

Confluence

The point where two rivers meet.

Corrosion

A type of erosion by water involving the dissolving away of rock, particularly chalk and limestone.

Delta

A depositional landform created where a river splits into numerous outlets.

River basin

An area of land drained by a river and its tributaries. Also known as a drainage basin.

Erosion

The wearing away of the land by material carried in rivers, glaciers, waves and wind.

Estuary

The last section of a river subject to tides.

Fault

A line of weakness in rock.

Fetch

The maximum distance over which wind can blow to form a wave.

Floodplain

The flat area either side of a river which is regularly flooded.

Gorge

A deep, steep-sided valley.

Headland

A promontory of more resistant rock which juts out into the sea.

Hydraulic action

A process of erosion involving water and air trapped in cracks and crevices.

Levee

An embankment next to a river channel, raised above the floodplain.

Longshore drift

A movement of sand and pebbles along a beach by wave action.

Lower course

The stage of a river as it nears the sea which is dominated by the process of deposition.

Mass movement

The movement of weathered soil and rock on a slope.

Meander

A bend in a river found in its middles and lower courses.

Middle course

The stage of a river between its upper and lower sections, containing a mixture of erosion and deposition.

Mouth

Where a river enters the sea (ocean or lake).

Oxbow lake

The cut-off remnant of a meander found in the lower course of a river.

Plunge pool

A deep pool which is eroded at the base of a waterfall.