Edexcel A Level Geography: Coastal Landscapes and Change

Comprehensive vocabulary flashcards covering coastal processes, geology, waves, erosion and depositional landforms, mass movement, sea level change, and coastal management along the Holderness Coast from Edexcel A Level Geography.

Littoral zone

The boundary zone between land and sea that extends out into the sea and onto the shore, constantly changing due to dynamic interactions and divided into the backshore, foreshore, nearshore, and offshore.

High-energy coastline

A stretch of coast exposed to powerful waves for much of the year where the rate of erosion exceeds deposition, characterized by rocky landscapes with cliffs, headlands, and shoreline platforms (e.g. Cornwall).

Low-energy coastline

A sheltered stretch of coast where waves are less powerful and the rate of deposition exceeds erosion, characterized by sandy beaches, coastal plains, and spits (e.g. Lincolnshire and Northumberland).

Coastal plain

An area of low, flat relief along a coast formed from weaker, younger sedimentary rocks and depositional environments, such as The Wash estuary system.

Lithology

The physical characteristics and geological structure of particular rocks, including rock type, strata, bedding planes, joints, folds, faults, and dip.

Strata

Distinct, individual layers of sedimentary or volcanic rock within a geological formation or cliff profile.

Bedding planes

Natural horizontal breaks or dividing planes between strata, formed by gaps in time during successive periods of rock deposition.

Joints

Vertical fractures in rock strata caused either by contraction as sediments dry out or by earth movements during tectonic uplift.

Folds

Bends and buckles in rock strata produced by tectonic stress and pressure, as seen in the Purbeck limestone of the Lulworth Crumple at Stair Hole.

Faults

Fractures formed when stress or pressure exceeds a rock's internal strength, along which blocks of rock slip and displace across fault planes.

Dip

The angle and direction at which rock strata lie relative to the horizontal, influencing whether cliff profiles are steep, vertical, or prone to sliding.

Concordant coast

A coastline where alternating bands of more-resistant and less-resistant rock run parallel to the shore, as along the southern coast of the Isle of Purbeck.

Discordant coast

A coastline where alternating bands of more-resistant and less-resistant rock run at right angles to the shore, forming headlands and bays as along eastern Purbeck.

Dalmatian coast

A type of concordant coastline formed when sea level rise drowns valleys running parallel to the coast, leaving ridge tops exposed as offshore islands (e.g. Croatia).

Haff coast

A type of concordant coastline where long barrier spits of sand and dunes enclose shallow lagoons (haffs) aligned parallel to the shore (e.g. southern Baltic Sea).

Wave refraction

The bending of incoming wave crests as they reach shallow water off headlands, concentrating erosive energy onto headlands and dissipating it within bays.

Fetch

The uninterrupted distance of open ocean water over which the wind blows to generate waves; greater fetch produces larger waves.

Swell waves

Mid-ocean waves generated by distant weather systems that travel thousands of miles across open water while retaining energy, appearing as larger waves on coasts.

Constructive waves

Low, surging waves with long wavelengths and low frequencies ($6\text{--}9\text{ per minute}$) whose swash exceeds backwash, building up sediment on beaches.

Destructive waves

High, steep, plunging waves with short wavelengths and high frequencies ($11\text{--}16\text{ per minute}$) whose backwash exceeds swash, scouring and removing beach sediment.

Berm

A ridge of coarse sand or shingle deposited near the upper limit of the high-tide mark by the strong swash of constructive waves.

Abrasion (corrasion)

A marine erosion process where waves hurl entrained sand, pebbles, and rock fragments against the cliff foot, chipping away at the bedrock.

Hydraulic action

A marine erosion process occurring when advancing waves trap and compress air in cliff joints, which expands explosively as the water recedes to widen fractures.

Corrosion (solution)

The chemical dissolving of alkaline rocks (such as chalk and limestone) or alkaline cements by weak acids naturally present in seawater.

Attrition

The gradual wear, smoothing, and reduction in size of moving rock fragments as they collide with one another in waves, tides, and currents.

Differential erosion

The selective, faster erosion of weaker rock types and structural weaknesses (faults, joints) compared to adjacent, more-resistant rock bands.

Wave-cut notch

A horizontal cut or groove excavated at the base of a cliff near the high-tide level by concentrated marine erosion, undercutting the cliff face.

Shoreline platform

A flat or gently sloping rock surface (less than $4^\natural$) left behind at low tide as a cliff retreats inland through repeated notch collapse.

Longshore drift

The zig-zag movement of sediment along a coast caused by swash carrying material obliquely up the beach and backwash dragging it straight down under gravity.

Tidal range

The relative vertical height difference between high and low tide, which generates powerful tidal currents in estuaries and narrow coastal channels.

Spit

A narrow depositional ridge of sand or shingle extending from the coastline out into the sea or partially across an estuary on a drift-aligned beach.

Recurved spit

A spit with a hooked, landward-curving distal end produced by wave refraction transporting sediment around into the sheltered water behind it.

Pioneer species

The first hardy plants (such as sea rocket, couch grass, or glasswort) to colonise bare sand or mud, binding sediment and adding nutrients to initiate succession.

Climatic climax community

The stable, final plant community (e.g. mature woodland) reached at the end of a plant succession, in balance with the prevailing climate of the area.

Sediment cell

A dynamic coastal system containing sources, transport pathways, and sinks, operating largely in isolation between prominent physical boundaries such as headlands.

Sediment budget

The overall balance between sediment entering a coastal sediment cell (inputs/sources) and sediment leaving or being stored within it (outputs/sinks).

Dynamic equilibrium (coastal)

The state of balance within a coastal system where morphology and sediment stores self-regulate via positive or negative feedback when conditions change.

Freeze-thaw weathering

A mechanical weathering process where water enters cracks in rock, freezes, expands by about $10\%$, forces the cracks wider, and creates angular scree fragments.

Salt-weathering

A mechanical weathering process where evaporating sea spray leaves salt crystals within porous rock, which grow and exert pressure that fractures the rock.

Carbonation

A chemical weathering process in which dissolved atmospheric carbon dioxide makes rainwater acidic, converting insoluble calcium carbonate in rock into soluble calcium bicarbonate.

Soil creep

The imperceptible, continuous downhill movement of individual soil particles under gravity, operating at speeds of less than $1\,\text{cm/year}$.

Solifluction

The slow downslope flow of water-saturated soil over an impermeable, permanently frozen permafrost layer in tundra regions, averaging $5\,\text{cm}\text{ to }1\,\text{m/year}$.

Rotational slumping

A rapid mass movement common in saturated permeable rock overlying impermeable clay, where cliff material rotates downslope along a curved slip plane.

Eustatic change

A global change in sea level resulting from variations in the volume of ocean water (e.g. melting glaciers) or changes in ocean basin capacity.

Isostatic change

A local vertical movement of the land surface relative to sea level, driven by ice loading (isostatic subsidence) or post-glacial unloading (isostatic recovery).

Raised beach

A former wave-cut platform and beach deposit elevated above modern sea level due to isostatic recovery, frequently fronting abandoned relic cliffs.

Ria

A sheltered, winding drowned river valley with an irregular shoreline, formed when sea levels rose post-glaciation to submerge unglaciated upland terrain (e.g. Kingsbridge).

Fjord

A long, steep-sided, drowned glacial trough with a U-shaped cross-section and hanging valleys, which is substantially deeper inland than at its entrance sill (e.g. Milford Sound).

Environmental refugees

People forced to migrate from their homes and homelands as a direct result of critical environmental degradation, rising sea levels, or climate hazards (e.g. citizens of Kiribati).

Boulder clay (glacial till)

An unsorted, unconsolidated deposit of clays, sands, and boulders left behind by glaciers, structurally weak and highly vulnerable to coastal erosion (e.g. Holderness).

Terminal groyne syndrome

Accelerated erosion of cliffs and beaches immediately downdrift of a coastal defence structure, caused by groynes blocking longshore drift and starving downdrift areas of sediment.

Rollback

An adaptation policy funded by the East Riding Coastal Change Fund that pays planning fees to relocate threatened coastal caravan parks, farms, and homes inland.