Coastlines 1

Question 1

Berm

Answer 1

Terrace of a beach formed in the backshore above the high tide water level. Common on accredting beaches.

Question 2

Lagoon

Answer 2

Body of water separated from the ocean by a natual barrier

Question 3

Spit

Answer 3

Formed where the prevailing wind blows at an angle to the coastline resulting in longshore drift

Question 4

Headland

Answer 4

Coastal landform, point of land usually high with sheer drop that extends into teh ocean.

Question 5

Tombola

Answer 5

Spit that connects the mainland to an island.

Question 6

Wave cut platform

Answer 6

Narrow flat area often found at the base of a sea cliff.

Question 7

Cliff

Answer 7

Mass rock that rises very high and vertical from the ocean.

Question 8

Storm bar

Answer 8

Sand bar formed by storms and progressive breaking and reforming of waves as they approach the beach.

Question 9

Erosion Scarp

Answer 9

Line of cliffs that has been formed by erosion.

Question 10

How are coastlines shaped

Answer 10

Tectonic plate movements
Shifts in climate patters and sea levels
Weather patterns
Movement of sediments and water (waves, currents, storms)

Question 11

What causes tidal movements

Answer 11

Gravitational lpull
Current strength
Wave action

Question 12

Define sand budget

Answer 12

Coastal management tool used to analyse and describe the different sediment inputs (sources) and outputs (sinks) on the coasts to predict change in a coastline over time.

Question 13

Define longshore drift

Answer 13

Geological process that consists of the transportation of sediments (clay, silt, sand and shingle) along a coast parallel to the shoreline.

Question 14

What causes longshore drift

Answer 14

Caused by wind, along with wave refraction can set up currents running parallel with the beach.

Question 15

Define refraction

Answer 15

Waves slow down and change direction in shallower water near the coast due to interaction with the seabed

Question 16

Define reflection

Answer 16

Waves bound back where there is a steep cliff or seawall

Question 17

Define diffraction

Answer 17

Waves bend when they get to a barrier such as an offshore rock or opening to a harbour

Question 18

Describe the processes of coastal erosion

Answer 18

HYDRAULIC ACTION - impact by wind, water on cliff face
CORROSION - cliffs erode as a result of weak acids in the sea.
ATTRITION - waves cause rick pieces to collide and grind down
SOLUTION - acids in sea water dissolve some types of rick
ABRASION - also known as corrasion when waves break on cliff faces and erode it.
CORROSION - clemical weather when seas ph is below pH 7.0 and corrode rocks.

Question 19

Characteristics of Accreting beach with constructive waves

Answer 19

Wider
Gentle slope
Microridges
Possible berm

Question 20

Characteristics of Eroding beach with destructive waves

Answer 20

Steep and hard
Black minerals appearing
Erosion scarp may be visible

Question 21

3 types of waves

Answer 21

Swell
Breakers
Tsunami

Question 22

Types of Breakers

Answer 22

Spilling waves - crumble from top on shallow beaches. Glentle waves
Plunging waves - throw from the top where bottom rises sharply. High energy, fast waves.
Surging waves - break from the full face as deep swells meet a cliff or rock. Strong backwash.
Collpsing waves - blend of plunging and surging waves causing lots of whitewater

Question 23

How do groynes prevent coastal erosion?

Answer 23

Acts as a physical barrier to interrupt wave action and protect the beach from being washed away by longshore drift. The Groyne traps the sediment and material being moved by longshore drift.

Question 24

Groyne

Answer 24

Built perpendicular to the shore is a rigid structure built from the ocean shore or bank that interrupts water flow and limits the movement of sediment or sand.

Question 25

Difference between a spit and tombolo

Answer 25

Tombolo is when a spit connects the mainland to an island
Spit is not connected to an island
Both formed by longshore drift or a river estuary depositing sand.