EV203: Coastal Processes

In what way(s) does water erode coast lines?

• Abrasion

• Hydraulic action

• Chemical weathering

• Salt wedging

Wave refraction describes

• the bending of waves around headlands

• the backwash of waves

• how waves disperse sunlight

Over time, wave refraction will

• smooth coastlines.

• erode bays.

• deposit sediment at headlands.

Sand and debris flow _________ the beach.

• in a zig-zag pattern along

• perpendicular to

• randomly along

The longshore current

• moves water and particles paralell to the shore

• follows local wind patterns

• is also known as undertow

The landform shown here is a spit. How did it form?

• The long shore current eroded away the island where the spit is now.

• The long shore current carried sand off the mainland and deposited it here in the deeper channel.

• Wind blew sand off shore and into the sea here.

• Engineers deposited the sand to protect the main land.

Which structure would you build to maintain an open waterway where a river meets the ocean or a large lake?

• A groin

• A spit

• A jetty

• A seawall

Groins help to

• protect a section of beach from erosion.

• prevent damage to small boats.

• prevent tsunamis.

• maintain an open channel.

Erosion occurs on the _______ side of a groin.

• up-current

• down-current

• neither

When a spit completely blocks off a bay a ______ is formed

• tombolo

• jetty

• column

• baymouth bar.