Transcript COASTAL LANDFORMS - 2015-Sec3-Geog

COASTAL
LANDFORMS
CLIFFS
SHORE
PLATFORMS
TOMBOLOS
LANDFORMS
HEADLANDS
SPITS
BEACHES
BAYS
Caves,
Arches,
Stacks
and
Stumps
CLIFF
It refers to a high,
steep rock face
along
a coast.
Cliff: Formation
Waves pound repeatedly against a rocky
coast.
This weakens the rock and causes lines of
weaknesses to form in the rock.
Over time, the waves erode the coast to
cut a notch along the lines of weaknesses
Cliff: Formation
The notch may be further eroded to form a
cave.
The overhanging part of the cave or notch
eventually collapses.
The part of the coast that is left forms a
cliff.
SHORE PLATFORM
It refers to a gently sloping, coastal land
surface with a cliff behind it.
Platform Formation
Due to constant erosion, the cliff retreats
inland.
Over time, a gently sloping surface
develops at the base of the cliff.
Rock fragments from the receding cliff are
deposited in this surface known as a shore
platform.
Draw: Cliff & Shore
Platform Formation
HEADLAND
It refers to a high steep faced cliff that
protrudes into the sea.
BAY
It refers to a wide, inward curve of the
coastline.
Formation
The coastline
consists of parallel
bands of hard and
soft rock
(perpendicular to
the sea).
Formation
Due to differential
erosion, the less
resistant rocks are
eroded faster than
the more resistant
rocks.
Formation
 The less resistant
rocks will curve
inwards to form bays.
 The more resistant
rocks will protrude from
the coastline to form
headlands.
Caves, Arches, Stacks
and Stumps
Formation
As waves approach the headland, the
waves gets refracted towards the
headland.
waves erode the headland along lines of
weaknessess (e.g. joints, faults and
bedding planes)
Two back-to-back caves first form on each
side of a headland.
Continuous erosion causes these back-toback caves to extends backward
till the sea caves meet and a natural tunnel
is produced.
The top portion of the sea caves becomes
an arch, linking the tip of the headland with
the mainland.
When the arch collapses , the sea ward
pillar is left standing and becomes a
stack.
Continual wave erosion eventually
reduces the stack into a stump.
BEACH
It refers to an
accumulation of
sediments on the
coast.
Formation
Materials eroded from the headlands,
together with other material carried by the
waves is deposited at the bay.
Fine materials form gently sloping
beaches while coarse materials form
beaches of steep gradient.
It refers to a long, narrow, ridge of sand
with one end connected to the land and
the other extends into the open sea.
SPIT
Formation
Longshore currents encounter a bay or
bend in a coast with shallow sheltered
water.
The materials the currents carry will be
deposited in the direction of the longshore
drift.
Formation
Over time, the accumulation of materials
will result in a long narrow ridge of sand.
One end of the ridge will be attached to
the mainland and the other extends into
the open sea.
This coastal feature is known as a spit.
TOMBOLO
It refers to a long, narrow, ridge of sand linking
the mainland to an island.
Formation
Tombolo is formed when a spit increased
in length until it joins a nearby island.
It can also be formed when two spits,
facing each other grow and eventually
meet.
CLIFFS
SHORE
PLATFORMS
TOMBOLOS
LANDFORMS
HEADLANDS
SPITS
BEACHES
BAYS
Caves,
Arches,
Stacks
and
Stumps
THE END