Transcript ws-71-721 - WordPress.com

WS 7.1, Page 21
1a) Strength of wind and fetch affect the size of
waves. The stronger to wind, the larger the size of
waves. The longer the distance over which wind
blows across open water, the larger the size of the
waves
1b) As the waves approach the shore, they will
experience friction with the increasingly shallow
sea bed. The waves lose energy and slow down.
However, the waves behind case the waves in
front to steepen. When the waves become too
steep, they will collapse and break to from a
swash. Gravity pulls the waves back into the sea,
forming the backwash on the beach.
WS 7.1, Page 22
2) When the waves reach the shore at an
angle, the swash carries the sediments up
onto the coast at the same angle./ The
backwash then carries the sediments back
to the sea at a right angle to the coast due
to the pull of gravity./ This motion is
repeated and gives rise to a zig-sag
movement of sediments along the coast,
known as the longshore drift.
WS 7.1, Page 22
3) The waves are acting mainly as an agent
of deposition because the photograph
shows small waves breaking on a gently
sloping beach.
WS 7.2, Page 23
1a) X: Headland; Y: Bay
1b) Headlands and bay are formed by wave
erosion where the coast is made of
alternating bands of resistant rocks and less
resistant rocks./ The different rates of
erosion on the rocks by the waves cause the
coast to be eroded unevenly. / The areas
made up of less resistant rocks are eroded
by the waves to form bays while the areas
with more resistant rocks will protrude into
the sea to form headlands.
WS 7.2, Page 24
2a) Z is a tombolo. A tombolo is a narrow
strip of sand that connects the mainland to a
small island nearby or an outcrop of rocks.
2b) Deposition as a result of longshore drift
results in the accumulation of a long narrow
ridge of sand./ This landform is know as a
spit./ As the spit extends seawards, it joins
an offshore island or an outcrop of rocks
near the coast to form a tombolo.