coastal landforms

Question 1

coastal landforms caused by erosion (Wave cut platforms)

Answer 1

1) Cliffs are common coastal landforms —> overtime cliffs retreat due to WEATHERING and WAVES.
2) WAVE CUT NOTCH form at the higher water mark which develops into a cave
3) rock above cave begins to be unstable with nothing to support it and collapses
4) WAVE CUT PLATFORMS are flat surfaces left behind when a cliff is eroded

Question 2

headlands and bays

Answer 2

1) headlands and bays form in a DISCORDANENT coastline
2) the soft rock is eroded quickly, forming a bay. the harder rock is eroded less and sticks out as headland

Question 3

Caves, Arches and Stacks

Answer 3

1) Some landforms are found in cliffs —> these are called cliff profile features.
2) Weak areas in rock (eg: joints) are eroded to form caves
3) caves on the opposite sides of a narrow headland may eventually join up up to form an arch
4) when an arch collapses, it forms a stack (old harry)

Question 4

coastal landforms due to Deposition beaches

Answer 4

1) beaches form when constructive waves deposit sediment on the shore —> in the coastal system.
2) Shingle beaches are steep and narrow —> larger particles pile up at steep angles —> sand beaches, formed from smaller particles, are wide and flat beaches
3) Berms are ridges of sand and pebbles found at high tide marks
- Runnels and Grooves in the sand running parallel to the shore formed by Backwash draining to the sea. Cusps are crescent-shaped indentations that form on beaches of mixed sand and shingle.

Question 5

spit formation

Answer 5

• usually forms when coasts suddenly change direction

1) LSD continuous to deposit material across the river mouth, leaving a bank of sand and shingle sticking out into sea
2) Changes in dominant wind and wave direction may lead to a spit having a curved end (HOOK FORMATION)
3) Overtime, several recurved ends may be abandoned as the waves return to original direction
4) the area behind the spit is sheltered from the waves so water becomes stagnant forming salt marshes

Question 6

offshore bars and tombolo’s

Answer 6

1) bars and formed when a spit joins 2 headlands together. this can occur across a bay or across river mouth
2) lagoon forms behind the bar
3) Bars can also form off the coast when the material moves towards the coast —> could remain partially submerged by the sea —> so they called OFFSHORE BARS
4) A bar that connects the shore to an island is called a TOMBOLO
5) ISLE OF MUCK —> MAGEE COASTLINE

Question 7

Barrier Islands//barrier beaches

Answer 7

1) Long, narrow islands of sand which run parallel to the shore and are detached from it.
-They form in areas rich in sediment, a gentle slope offshore, fairly powerful waves and a small tidal range

2) After last ice age when ice melted —> Rising water flooded the land behind beaches transported sand offshore, where it was deposited in shallow water, forming islands

3) another theory is that originally bars —> attached to coast —> eroded in sections, causing breaches in the bar

4) Lagoon/Marsh often forms behind the barrier island, where the coast is sheltered from wave action