coats geogrpahy

explain the process of longshore drift.

• Waves approach the beach at an angle because of the prevailing wind.

• Swash carries sediment up the beach at that angle.

• Backwash carries sediment straight down the beach under gravity.

• Repeated movement transports sediment along the coast in a zigzag pattern.

how headland and bays are formed

• A coastline has alternating bands of hard and soft rock.

• Waves erode the softer rock more quickly.

• The softer rock retreats inland, forming a bay.

• The harder rock remains sticking out into the sea, forming a headland.

how caves, arches, and stumps are formed

• Crack: waves widen weaknesses in the rock through hydraulic action and abrasion.

• Cave: the crack becomes a larger hollow.

• Arch: erosion breaks through the headland, creating an opening.

• Stack: the arch roof collapses, leaving an isolated column of rock.

• Stump: further erosion and weathering reduce the stack to a short remnant, often visible at low tide.

how beaches are formed

• Waves carry sand, pebbles and other sediment towards the coast.

• When waves lose energy, they deposit the sediment.

• Repeated deposition builds up a beach.

how spits are formed.

• Longshore drift transports sediment along the coast.

• The coastline changes direction, or a river mouth creates an opening.

• Sediment continues to be deposited out into the sea.

• A long, narrow ridge of sediment called a spit develops.

• Its end may curve due to changes in wave direction or wave conditions.

how sand dunes are formed

How they form:

1. Wind blows dry sand from the beach inland.

2. Obstacles, such as driftwood, slow the wind and trap sand.

3. Marram grass grows in the sand and traps more particles with its stems.

4. More sand accumulates, gradually building dunes.

conditins for coral reefs

1. Warm water — temperatures of about 23–29°C.

2. Shallow water — sunlight can reach the coral and its algae.

3. Clear water — little sediment, so sunlight can penetrate.

4. Sunlight — needed by the algae living inside coral polyps for photosynthesis.

5. Salty water — normal marine salinity.

6. Clean, unpolluted water — pollution can harm coral growth.

7. Well-oxygenated water — provides oxygen for marine organisms.

8. A hard surface — gives coral larvae somewhere to attach and grow.