humanities test

Swash is the forward movement of water up the beach after a wave breaks. It carries sand and sediments onto the shore, helping to build up the beach.
Backwash is the water flowing back into the sea after a wave retreats. It can pull sand and sediments away from the beach, contributing to erosion.

How waves change the coast:

Change & Environment: Waves cause erosion by wearing away cliffs and shorelines, and deposition by building up beaches and sand dunes.
Interconnection & Scale: Large, powerful waves (from storms) can reshape coastlines quickly, while smaller waves create gradual changes over time.

This is what happens to sand on a beach where the waves strike directly onto the beach:

1) Sand moves straight in and out – The waves push sand up the beach and pull it straight back, leading to minimal lateral movement.
2) No longshore drift – Unlike angled waves, which create longshore drift, direct waves do not transport sand along the coast.
3) Steeper beach formation – Repeated direct wave action can move sand offshore, making the beach steeper over time.

A grain of sand follows a zigzag pattern along the shore due to angled waves.

Rocks erode at different rates due to hardness (soft rocks like sandstone erode faster than hard rocks like granite) and exposure (constant waves, wind, and chemical weathering speed up erosion).

Constructive waves add sand to a beach because they have strong swash (which carries sand up the beach) and weak backwash (which doesn’t pull much sand away). This builds up the beach over time.

Different ways humans use coastlines:

•Tourism – People visit for swimming, surfing, and holidays.

•Fishing – Catching fish and farming seafood.

•Transport – Ships move goods and people.

•Living – Many people build homes near the coast.

•Industry – Factories, wind farms, and oil rigs.

Coastal protection – Sea walls and dunes stop erosion.