Classifying coastal landscapes

Question 1

Coasts can be divided into which two main types?

Answer 1

Rocky (or cliffed) coastlines with cliffs varying in height from a few metres to hundreds of metres.
Coastal plains (with no cliffs) where the land gently slopes towards the sea across an area of deposited sediment, often in the form of sand dunes and mud flats.

Question 2

Formation processes: What are primary coasts?

Answer 2

Primary coasts are dominated by land-based processes, such as deposition at the coast from rivers or new coastal land formed from lava flows.

Question 3

Formation processes: What are secondary coasts?

Answer 3

Secondary coasts are dominated by marine erosion or deposition processes.

Question 4

Relative sea level change: What are emergent coasts?

Answer 4

Emergent coasts are where the coast is rising relative to sea level, for example as a result of tectonic uplift.

Question 5

Relative sea level change: What are submergent coasts?

Answer 5

Submergent coasts are being flooded by the sea either because of sea level rise and/or subsiding land.

Question 6

Tidal range: What is the name for a tidal range of 0-2m?

Answer 6

Microtidal

Question 7

Tidal range: What is the name for a tidal range of 2-4m?

Answer 7

Mesotidal

Question 8

Tidal range: What is the name for a tidal range of greater than 4m?

Answer 8

Macrotidal

Question 9

Coasts can be classified according to which different physical features and processes?

Answer 9

Formation processes
Relative Sea level change
Tidal range
Wave energy

Question 10

Wave energy: What is low energy?

Answer 10

Low energy sheltered coasts with limited fetch and low wind speeds resulting in small waves.

Question 11

Wave energy: What is high energy?

Answer 11

High energy exposed coasts, facing prevailing winds with long wave fetches resulting in powerful waves.

Question 12

What are high relief cliffs composed of?

Answer 12

Relatively hard rock

Question 13

What are the two main cliff profile types?

Answer 13

Marine erosion dominated

Subaerial process dominated

Question 14

What are marine erosion dominated cliff profile types?

Answer 14

Wave action dominates the cliffs tend to be steep, unvegetated and there is little rock debris at the base of the cliff.

Question 15

What are subaerial process dominated cliff profile types?

Answer 15

Not actively eroded at the base by waves; shallower curved slope and lower relief; surface runoff erosion and mass movement are responsible for the cliff shape.

Question 16

What do subaerial processes include?

Answer 16

Subaerial processes include weathering processes (mechanical/physical, chemical and biological), mass movement processes and surface runoff erosion.

Question 17

What does accretion refer to?

Answer 17

Accretion refers to the deposition of sediment at a coast that expands the area of land.

Question 18

What do many coastal plains include?

Answer 18

Estuary wetlands and marshes, being just above sea level and poorly drained because of the flatness of the landscape.

Question 19

When do coastal plains form?

Answer 19

When the sea level falls, exposing the sea bed of what was once a shallow continental shelf sea e.g. the Atlantic coastal plain the the United States.
Sediment brought from the land by river systems is deposited at the coast causing coastal accretion so coastlines gradually move seaward, such as a river delta.
Sediment is moved from offshore sources (sand bars) towards the coast by ocean currents.