Week 10: Shorelines

Question 1

Name and describe the two types of Coastline

Answer 1

• Emergent: exposed by relative fall in sea level

e.g. - raised beaches, high cliffs, headlands, exposed bedrock, arches, rocky shores

• Submergent: Submerged by relatve sea level rise (relative to land)

e.g. - flooded river mouths, fijords, barrier island, lagoons, bays, estuaries

Question 2

Name and describe the 5 main shoreline zones

Answer 2

Offshore: not affected by active wave turbidity currents

Nearshore: Affected by waves with water depth of 1/2 wavelength (depends on wavelength and water depth)

Surf Zone: Actively breaking waves

Foreshore: Periodically wet and dry due to waves and tide

Backshore: Typically always above sea level (sometimes dunes form)

Question 3

The balance between sediment _______ and _________ drives the evolution of the coast

Answer 3

demand and supply

Question 4

What is Soft Engineering?

Answer 4

The use of natural management techniques to tackle erosion, not artifical structures

e.g. Dune Nourishment and Reprofiling

Question 5

What is Dune Nourishment and Reprofiling?

Answer 5

Dune Nourishment: restoration of dunes using plants

Reprofiling: The movement of sediment around the beach to limit the effects of erosion

Question 6

What is Hard Engineering?

Answer 6

When erosion cannot be managed by soft engineering, building artificial structures is required

E.g. - Sea Walls, Groynes, Rock armour or rip rap

Question 7

How do waves move?

Answer 7

Gravity pulls teh water in the crests downward. Forced out from beneath the falling crests, the falling water pushes teh former troughs upward and the wave moves to a new position.

Question 8

Waves transmit _________, not __________

Answer 8

energy, not water

Question 9

What is the coastal cell?

Answer 9

The concept of a balanced coastline where there is mass balance of sediment inputs and outputs