Coasts: Depositional Landforms

Question 1

Spit

Answer 1

Sand/shingle beach extending beyond a turn in the coastline greater than 30°

At the turn, longshore drift current spread out, loses energy leading to Deposition

Length of spit is determined by the existence of secondary currents causing erosion

Question 2

Bar

Answer 2

Sand/shingle beach connecting two areas of land, with a shallow lagoon behind

Occurs when a spit is long enough to extend across a bay

Question 3

Tombolo

Answer 3

Sand/shingle bar attaching the coastline to an offshore island

Forms due to wave refraction around offshore island

Causes low energy environment -> deposition between island and coast

Question 4

Hooked/recurved spit

Answer 4

Spit that’s curved landward due to a change in prevailing wind direction

Question 5

Bayhead beach

Answer 5

Fault penetrated in concordant coastline leads to erosion of less resistant rock by sea

Wave refraction causes bay to be an area of deposition

Question 6

Offshore bar

Answer 6

Ridge of sand offshore, can be submerged during high tide

Initially formed by rip tide currents following destructive waves