Processes Of Coastal Transport And Deposition And The Associated Landforms

Question 1

What is traction?

Answer 1

Sediment rolls or slides along the sea bed

Question 2

What is saltation ?

Answer 2

Sediment is bounced along the sea bed

Question 3

What is suspension?

Answer 3

Small particles are held and moved in the water

Question 4

What is solution?

Answer 4

Material dissolved in the water and is moved by the sea

Question 5

What is the process of longshore drift?

Answer 5

Waves approach at an angle due to prevailing winds. Smash washes sediment diagonally up the beach.
Gravity pulls backwash with sediment straight down the beach.
Repeated action results in the net movement of sediment along the beach parallel to the shoreline. The direction is predominantly one way due to prevailing winds. Changes in wind direction can result in movement in the opposite direction.

Question 6

What is flocculation?

Answer 6

Where fresh water mixes with sea water such as in a river estuary. Clay particles coagulate due to chemical reactions to form flocs, which are heavier and more likely to be deposited.

Question 7

What 4 reasons does deposition occur for?

Answer 7

When waves lose velocity after breaking
When backwash percolates quickly into the beach
When sheltered coastlines reduce the wave energy
As a result of flocculation

Question 8

How is sediment sorted?

Answer 8

Large sediment deposited furthest from the sea by high energy waves. By a storm. Creates a storm beach.
Smaller material deposited near the sea.
Material nearer the sea is prone to attrition, gets eroded into smaller particles

Question 9

3 types of beaches

Answer 9

Smash aligned beach
Drift aligned beach
Zeta formed beach

Question 10

Dominant waves and sediment movement of a swans aligned beach

Answer 10

Waves break parallel to shore

Sediment moves onshore/offshore

Question 11

Dominant waves and sediment movement of drift aligned beach

Answer 11

Waves break at an oblique angle to the shore

Longshore drift along the shore

Question 12

Dominant waves and sediment movement of zeta formed beach

Answer 12

Waves break at an oblique angle but a headland at each end causes wave refraction, blocking sediment movement.

Longshore drift along the coast, but sediment builds up in front of a headland

Question 13

What is a spit?

Answer 13

A linear ridge of sediment joined to the land at one end

Proximal end joined to mainland

Distal end lies in open water

Question 14

Formation of a spit

Answer 14

Longshore drift moves sediment along a coast.
Where the coastline suddenly changes direction, the material continues to be deposited in the original direction.
Winds may cause distal end to curve. Eg hurst spit, in Hampshire.
Sheltered water behind may form a mudflat or saltmarsh.

Question 15

Formation of a bar

Answer 15

When a spit grows to form a ridge that blocks off a bay creating a lagoon. Eg slapton sands, in Devon.
A bar might start by as deposits driven onshore by rising sea levels. Eg chesil beach, in Dorset.
If a bar is not connected to the mainland it is a barrier island. Eg scolt head Island off the Norfolk coast.

Question 16

What’s a tombolo?

Answer 16

A tombolo is a spit or bar that joins the mainland to an island. Eg the Eastern end of chesil beach where it joins the isle of Portland

Question 17

What’s cuspate foreland?

Answer 17

Triangular shaped projection from the shoreline made up of a series of ridges created by longshore drift from opposing directions. Eg Dungeness in Kent