Geography: Rivers, Coasts, Weather, and Natural Hazards

Vocabulary flashcards covering plate tectonics, river processes and landforms, coastal geography, and weather measurement instruments based on the lecture notes provided lecture notes.

Constructive Plate Boundary

A plate boundary where plates move away from each other, allowing magma to rise and form new crust.

Destructive Plate Boundary

A plate boundary where plates move towards each other, often involving a subduction zone where oceanic crust melts due to friction.

Conservative Plate Boundary

A plate boundary where plates slide past each other, accumulating pressure that is released as earthquakes without volcanic activity.

Subduction Zone

An area at a destructive margin where oceanic crust sinks into the mantle and melts due to heat and friction.

Active Volcano

A volcano that has erupted recently.

Dormant Volcano

A volcano that has not erupted recently but may erupt in the future.

Extinct Volcano

A volcano that is unlikely to erupt again because it contains no magma.

Drainage Basin

The area of land drained by a river.

Watershed

The edge of highland surrounding a drainage basin that marks the boundary between two drainage basins.

Confluence

The point at which two rivers join together.

Tributary

A smaller river that joins a larger river.

Thalweg

The fastest part of the river, always located near the middle of the river channel.

Attrition

A type of erosion where river or coastal materials smash into each other, becoming smaller and rounder.

Hydraulic Action

Erosion caused when water is forced into cracks of a bank or cliff, compressing air and widening the cracks.

Abrasion

The grinding away of the river bed, bank, or cliff face by sediment and rocks carried by the water.

Traction

A transportation process where large, heavy rocks or boulders roll or slide along the river bed or seabed.

Saltation

A transportation process where small stones, pebbles, or silt bounce along the bed of a river.

Suspension

A transportation process where fine materials such as clay and sediment are carried along by the water.

Solution

A process where water dissolves materials, serving as both a method of erosion and transportation.

Waterfall

A river landform created when a river flows over hard rock on top of soft rock, eroding the soft rock more quickly to form a plunge pool.

Meander

A bend or curve in a river formed by lateral erosion on the outside bank and deposition on the inside bank.

Ox-bow Lake

A crescent-shaped lake formed when a meander neck is breached during a flood and the old loop is sealed off by deposition.

Levee

A raised natural bank along a river channel formed by the repeated deposition of heavy sediment during flood events.

Swash

The movement of water breaking and washing up onto the beach after a wave breaks.

Backwash

The movement of water draining back down the beach into the sea under the influence of gravity.

Longshore Drift

The zig-zag movement of sediment along a coast caused by waves approaching the beach at an angle determined by the prevailing wind.

Spit

A coastal landform consisting of a ridge of sand or shingle deposited by longshore drift that builds out into the sea where the coastline changes direction.

Stevenson’s Screen

A white, wooden, slatted box used to house thermometers, designed to reflect sunlight and allow air circulation while shielding instruments from direct heat.

Rain Gauge

A weather instrument with a fixed-diameter funnel used to measure rainfall depth in $mm$.

Anemometer

An instrument with rotating cups mounted on a pole used to measure wind speed in units such as $m/s$ or knots.

Sunshine Recorder (Heliograph)

An instrument using a glass sphere to focus sun rays onto a card, burning a trace to record the duration of bright sunshine in hours per day.

Max-min Thermometer (Six’s Thermometer)

A U-shaped tube containing mercury and alcohol used to measure the highest and lowest temperatures over a $24$-hour period.

Hygrometer (Wet & Dry Bulb Thermometer)

A pair of thermometers used to measure relative humidity by calculating the temperature difference (depression) caused by evaporation from a wet wick.

Barometer

A weather instrument used to measure air pressure in millibars, hectopascals, or $mmHg$ using a flexible vacuum chamber.

Wind Vane

An instrument with an arrowhead and fletching used to record the direction the wind is blowing from.

Mangroves

Tropical or subtropical trees that grow in sheltered, low-energy saline environments with soft, oxygen-poor mudflats.

Coral Reefs

Diverse marine structures built from limestone remains that require warm water ($20 - 30^\circ C$), shallow depths (less than 60\,
ext{m}), and clear, unpolluted water.