Shoreline Erosion

Waves and Wind Shape the Shoreline

Waves● Waves pound the rocks and shells creating

sand.● The sand on a beach will consist of

particles eroded from the surrounding area.● Hawaii's black sand beaches come from

the volcanic rock nearby.● White sand beaches come from shells and

coral.

Longshore Drift● The longshore current ( runs parallel to

shore) creates the longshore drift.● Longshore drift moves large amounts of

sand along beaches.● Groins are installed to keep sand from

drifting.

Longshore Drift● cat

Sand Trapped By Groins● cat

Longshore Current Landforms● Longshore current also transport sand to

form sandbars and spits● Spit – is a sand bar that has built up above

the waters surface with one end joined to land.

● Bay mouth bar- a spit that complete blocks a bay and creates a lagoon

● Tombolo – is an island that join to land by a thin strip of sand.

Spit● This spit is almost a

bay mouth bar

Tombolo● cat

Barrier Island● Barrier island are

formed by erosion and deposition

Headland● Headland – an area

of coastline that protrudes further into the sea than the surrounding coast.

Sea Arch● Sea arches form

when softer stone is eroded behind the headland.

Sea stack● Stacks form when

the roof of a sea arch collapses.