Formation of different land-forms along the coast due to wave action and other processes are explained here

1. EVOLUTION OF COASTAL LANDFORMS
PRESENTER: SALAHUDIN KHURSHEED
PRESENTED TO: SIR, GHAFFAR

2. What is coast?
The coast, also known as the coastline or seashore, is
the area where land meets the sea or ocean or a line
that forms the boundary between the land and the ocean

3. CURRENTS AND TIDES
An ocean current is a continuous, directed movement of sea water
generated by a number of forces acting upon the water, including wind, the
breaking waves, cabbeling, and temperature and salinity differences.
Depth contours, shoreline configurations, and interactions with other
currents influence a current's direction and strength. Ocean currents are
primarily horizontal water movements
CURRENT:

4. TIDES:
Tides are the rise and fall of sea levels caused by
the combined effects of the gravitational forces
exerted by the Moon and the Sun, and the rotation
of the Earth.

6. WAVES:
All waves including seismic, sound, water or
any other kind transport energy

9. Any of the relief features present along any coast, the result of a
combination of processes, sediments, and the geology of the coast itself.
Coastal landforms:
The coastal environment of the world is made up of a wide variety of
landforms manifested in a spectrum of sizes and shapes ranging from gently
sloping beaches to high cliffs, yet coastal landforms are best considered in two
broad categories: erosional and depositional. In fact, the overall nature of any
coast may be described in terms of one or the other of these categories. It
should be noted, however, that each of the two major landform types may
occur on any given reach of coast

10. Factors And Forces In The Formation Of Coastal
Features:
The landforms that develop and persist along the coast are the result of a
combination of processes acting upon the sediments and rocks present in the
coastal zone. The most prominent of these processes involves waves and the
currents that they generate, along with tides. Other factors that significantly affect
coastal morphology are climate and gravity.

11. Waves:
The most obvious of all coastal processes is the continual motion of the waves moving toward the
beach. Waves vary considerably in size over time at any given location and also vary markedly from
place to place. Waves interact with the ocean bottom as they travel into shallow water; as a result,
they cause sediment to become temporarily suspended and available for movement by coastal
currents. The larger the wave, the deeper the water in which this process takes place and the larger
the particle that can be moved. Even small waves that are only a few tens of centimetres high can
pick up sand as they reach the shore. Larger waves can move cobbles and rock material as large as
boulders.
Generally, small waves cause sediment—usually sand—to be transported toward the coast and to
become deposited on the beach. Larger waves, typically during storms, are responsible for the
removal of sediment from the coast and its conveyance out into relatively deep water.
Waves erode the bedrock along the coast largely by abrasion. The suspended sediment particles in
waves, especially pebbles and larger rock debris, have much the same effect on a surface as
sandpaper does. Waves have considerable force and so may break up bedrock simply by impact

12. Longshore currents:
Waves usually approach the coast at some acute angle rather than exactly parallel to it.
Because of this, the waves are bent (or refracted) as they enter shallow water, which in
turn generates a current along the shore and parallel to it. Such a current is called a
longshore current, and it extends from the shoreline out through the zone of breaking
waves. The speed of the current is related to the size of the waves and to their angle of
approach. Under rather quiescent conditions, longshore currents move only about 10–
30 centimetres per second; however, under stormy conditions they may exceed one
metre per second. The combination of waves and longshore current acts to transport
large quantities of sediment along the shallow zone adjacent to the shoreline.
Because longshore currents are caused by the approaching and refracting waves, they
may move in either direction along the coast, depending on the direction of wave
approach. This direction of approach is a result of the wind direction, which is therefore
the ultimate factor in determining the direction of longshore currents and the transport of
sediment along the shoreline.

14. Rip current, also called riptide, narrow jetlike stream of water that flows
sporadically seaward for several minutes, in a direction normal or nearly normal to
a beach. Such currents are probably the cause of most ocean bathing accidents
blamed on undertow. The term riptide is often used but is a misnomer, the currents
being related in no way to tides.
Rip currents may have velocities as great as 1 metre per second (3.3 feet per
second, or 2 knots) and extend offshore from 60 to 760 metres (200 to 2,500 feet).
The energies of the currents may be sufficient to erode shallow channels through
offshore bars, and the water may be discoloured by suspended sand. Swimmers
caught in a rip current should not attempt to swim shoreward directly against the
current. Instead, it is best to swim a short distance parallel to the beach to emerge
from the rip current before returning to shore.
RIP CURRENT:

16. The rise and fall of sea level caused by astronomical conditions is regular and
predictable. There is a great range in the magnitude of this daily or semi-daily change
in water level. Along some coasts the tidal range is less than 0.5 metre, whereas in
the Bay of Fundy in southeastern Canada the maximum tidal range is just over 16
metres. A simple but useful classification of coasts is based solely on tidal range
without regard to any other variable. Three categories have been established: micro-
tidal (less than two metres), meso-tidal (two to four metres), and macro-tidal (more
than four metres). Micro-tidal coasts constitute the largest percentage of the world’s
coasts, but the other two categories also are widespread.
Tides:

17. EROISIONAL LANDFORMS
The process of erosion can create different landforms along the
coastline.
Headlands and bays:
Cliffs along the coastline do not erode at the same pace. When a stretch of coastline is
formed from different types of rock, headlands and bays can form.
Bands of soft rock such as clay and sand are weaker therefore they can be eroded
quickly. This process forms bays. A bay is an inlet of the sea where the land curves
inwards, usually with a beach. Hard rock is more resistant to the processes of erosion.
When the softer rock is eroded inwards, the hard rock sticks out into the sea, forming a
headland.

19. Cliffs and wave-cut platforms:
Cliffs are shaped through erosion and weathering. Soft rock erodes
quickly and forms gentle sloping cliffs, whereas hard rock is more
resistant and forms steep cliffs. A wave-cut platform is a wide
gently-sloping surface found at the foot of a cliff.

20. 1-The sea attacks the base of the cliff between the
high and low water mark.
2-A wave-cut notch is formed by erosional processes
such as abrasion and hydraulic action - this is a dent
in the cliff usually at the level of high tide.
3-As the notch increases in size, the cliff becomes
unstable and collapses, leading to the retreat of the
cliff face.
4-The backwash carries away the eroded material,
leaving a wave-cut platform.
The process repeats. The cliff continues to retreat.

21. Caves, arches, stacks and stumps
Caves, arches, stacks and stumps are erosional features that are
commonly found on a headland.

22. 1-Cracks are widened in the headland through the erosional processes of
hydraulic action and abrasion.
2-As the waves continue to grind away at the crack, it begins to open up to
form a cave.
3-The cave becomes larger and eventually breaks through the headland to
form an arch.
4-The base of the arch continually becomes wider through further erosion,
until its roof becomes too heavy and collapses into the sea. This leaves a
stack (an isolated column of rock).
5-The stack is undercut at the base until it collapses to form a stump

23. When water loses its energy, any sediment it is carrying is
deposited. The build-up of deposited sediment can form different
features along the coast.
Depositional landforms
Beaches:
Beaches are made up from eroded material that has been
transported from elsewhere and then deposited by the sea. For this to
occur, waves must have limited energy, so beaches often form in
sheltered areas like bays. Constructive waves build up beaches as they
have a strong swash and a weak backwash.

24. Sandy beaches are usually found in bays where the
water is shallow and the waves have less energy. Pebble
beaches often form where cliffs are being eroded, and
where there are higher energy waves.
A cross-profile of a beach is called the beach profile. The beach profile has lots of
ridges called berms. They show the lines of the high tide and the storm tides. A
sandy beach typically has a gentle sloping profile, whereas a shingle beach can be
much steeper. The size of the material is larger at the top of the beach, due to the
high-energy storm waves carrying large sediment. The smallest material is found
nearest the water as the waves break here and break down the rock through attrition

25. Beach cusps are shoreline formations made
up of various grades of sediment in an arc
pattern. The horns are made up of coarser
material and the embayment contains finer
sediment. They can be found all over the
world and are most noticeable on shorelines
with coarser sediment such as pebble
beaches.
Beach cusps:

27. A raisedbeach, coastal terrace, or perched coastline is a
relatively flat, horizontal or gently inclined surface of
marine origin, mostly an old abrasion platform which has
been lifted out of the sphere of wave activity. Thus, it lies
above or under the current sea level, depending on the
time of its formation
Raised Beach:

29. Mudflats:

30. is a coastal inlet formed by the partial submergence of an
unglaciated river valley. It is a drowned river valley that remains
open to the sea. Typically, rias have a dendritic, treelike outline
although they can be straight and without significant branches.
This pattern is inherited from the dendritic drainage pattern of
the flooded river valley. The drowning of river valleys along a
stretch of coast and formation of rias results in an extremely
irregular and indented coastline. Often, there are naturally-
occurring islands, which are summits of partly submerged,
preexisting hill peaks
Ria:

32. a shoal is a natural submerged ridge, bank, or bar that
consists of, or is covered by, sand or other unconsolidated
material, and rises from the bed of a body of water to near
the surface. Often it refers to those submerged ridges,
banks, or bars that rise near enough to the surface of a body
of water as to constitute a danger to navigation. Shoals are
also known as sandbanks, sandbars, or gravelbars. Two or
more shoals that are either separated by shared troughs or
interconnected by past or present sedimentary and
hydrographic processes are referred to as a shoal complex
Shoal:

34. A spit or sandspit is a deposition bar or beach landform off coasts or lake
shores. It develops in places where re-entrance occurs, such as at a
cove's headlands, by the process of longshore drift by longshore
currents. The drift occurs due to waves meeting the beach at an oblique
angle, moving sediment down the beach in a zigzag pattern. This is
complemented by longshore currents, which further transport sediment
through the water alongside the beach. These currents are caused by
the same waves that cause the drift
SPIT:

36. a deposition landform
in which an island is
attached to the
mainland by a narrow
piece of land such as a
spit or bar. Once
attached, the island is
then known as a tied
island.
Tombolo:

37. A lagoon is a
shallow body of
water separated
from a larger
body of water by
barrier islands or
reefs
lagoon: