3.3 0 How LSD Creates Distinct Coasts

Question 1

Swash Aligned Coasts

Answer 1

Wave crests are parallel to the coast
Swash transfers sediment 90 to shoreline
Wave refraction around headlands
Most deposition when waves are constructive
Limited Longshore Movement - Marine Transgression

Question 2

Drift Aligned Coasts

Answer 2

LSD
Swash comes in at 30 degrees
Backwash out perpendicular because of gravity and sediment is transported in direction of prevailing wind.

Question 3

Intereference In LSD

Answer 3

Where transport of material is stopped/changed e.g. river flow or wind.

Question 4

Wave Refraction In LSD

Answer 4

Energy levels of the wave change, the direction of the material transport has also probably changed.

Question 5

Distance Decay/Gravity Settling

Answer 5

Wave energy is reduced, larger material is deposited, smaller material is deposited further.

Question 6

Why Might Waves Not Have Energy

Answer 6

Wind dropping, Obstruction, Wave Refraction, Friction

Question 7

Beaches

Answer 7

Accumulation of sediment produced by constructive waves. Swash is strong whilst backwash is weak, sediment is not able to be carried up by the beach.

Question 8

Bayhead Beach

Answer 8

Curved beach, in swas aligned coasts, wave refraction distributes energy unevenly, sedminet i smoved up bay, so serosion is concentrated on headlands and deposition is in bays.

Question 9

Spits

Answer 9

Linear ridges of sand stretching into the sea but still connected to the land, at drift aligned coastline, LSD occurs at the curve and wave refraction causes wave energy to disperse. The length is determined by river/wave action.

Question 10

Tombolo

Answer 10

A sand/shingle bar attaching the coast to an offshore isalnd/ Wave refraction around an offshore island, creates calm water and hence deposition between the island and the coast.

Question 11

Barrier Beach/Bar

Answer 11

A sand/shingly beach connection two areas of land with shallow water behind it, when a spit is so long it connect to another pece of land

Question 12

Hooked/Recurved Spit

Answer 12

A spit that’s end is curved landward into a bay. The seaward end gradually curves into shallow water.

Question 13

Offshore Bar

Answer 13

A ridge of sand found offshore can be submerged during hightide. Initially formed by rip-tide currents following destructive waves.

Question 14

Double Spit

Answer 14

Lagoon created by low-energy behind the spit. Tidal Gap - between 2 steps and formed in different directions. Water moving between them prevents them from meeting.

Question 15

Recurved pit

Answer 15

DOminant winds cause deopisiton in different direction. Marsh-low energy environment behind the spit leads to subsequent flocullation of small clay-particles carried by the river.

Question 16

Barrier Beach

Answer 16

Very flat, the origin of beach material either from the headland, or rolled inland as sea.

Question 17

Bayhead Beach

Answer 17

Ridges created by high-tide. Cusps - steeper gradient so smaller sediment is transported. up the beach, whilst backwash removes the larger sediment