coastal Geomorphology Landforms Of Wave Erosion and Wave Deposition

1. KRISHNAPRASAD PK
1st MSc
Dept Of Geology
University of Calicut

2.  COASTAL GEOMORPHOLOGY : is a branch of geomorphology
in which the focus is on the area influenced by large bodies of
water, including seas and oceans, and large lakes such as the Great
Lakes in North America.

4. WAVES: are generated by wind blowing over the sea. be transported toward
the coast and to become deposited on the beach, and erode the bedrock along
the coast largely by abrasion.
LONGSHORE CURRENT: is an ocean current that moves parallel to
shore. combination of waves and longshore current acts to transport large
quantities of sediment
RIP CURRENTS : type of coastal current caused by wave activity. and are
powerful, narrow channels of fast-moving water that are prevalent along the
coasts , as well as along the shores of the Great Lakes., can move faster
TIDES : in coastal landforms is , tidal currents transport large quantities of
sediment and may erode bedrock, and the rise and fall of the tide distributes
wave energy across a shore zone by changing the depth of water and the position
of the shoreline.

5.  CLIMATE
Rainfall : runoff in the form of streams and also is a factor in producing and
transporting sediment to the coast.
Temperature : factor in the physical weathering of sediments and rocks along the
coast
and in the adjacent drainage basins.
Wind : is important primarily because of its relationship to waves. key factor in
directly
forming coastal landforms, particularly coastal dunes.
GRAVITY : too, plays a major role in coastal processes. It is directly involved through
downslope movement of sediment and rock as well.

6. Attrition
Materials carried by the waves bump into each other and so are smoothed and broken
down into smaller particles
Hydraulic action
This process involves the force of water against the coast. The waves enter cracks (faults)
in the coastline and compress the air within the crack. When the wave retreats, the air
in the crack expands quickly, causing a minor explosion.
This process is repeated continuously.
Corrosion
This is the chemical action of sea water. The acids in the salt water slowly dissolve rocks
on the coast. Limestone and chalk are particularly prone to this process
Abrasion/Corrasion
This is the process by which the coast is worn down by material carried by the waves.
Waves throw these particles against the rock, sometimes at high velocity.

7.  HEADLANDS
 BAY
 SEA CLIFFS
 WAVE-CUT PLATFORM
 SEA ARCHES
 SEA STACKS
 SEA CAVES
 SEA STUMPS

9. Headlands : is a coastal landform, a point of land usually high and often
with a sheer drop, that extends out into a body of water. A headland of
considerable size often is called a cape. Headlands are characterised by high,
breaking waves, rocky shores, intense erosion, and steep sea cliffs.
Headlands and bays are often found on the same coastline. A bay is surrounded
by land on three sides, whereas a headland is surrounded by water on three sides
Chalk Headland on South Coast of England, England.

10. BAY : A bay is a body of water connected to an ocean or lake, formed by
an indentation of the shoreline. A large bay may be called a gulf,
a sea, a sound, or a bight
View of BAY OF KOTOR , ITALY

11. SEA CLIFFS: The most widespread landforms of erosional coasts are sea
cliffs. These very steep to vertical bedrock cliffs range from only a few meters
high to hundreds of meters above sea level
WORLD’S HIGHEST SEA
CLIFFS ON MOLOKAI, HAWAII
Located on the shore of the
Pacific Ocean in the Molokai
island of Hawaii,
Cliffs are the highest sea cliffs in
the world with a height of 1,010
meters (3,315 ft)

12.  WAVE-CUT PLATFORMS: is the narrow flat area often found at the
base of a sea cliff or along the shoreline of a lake, bay, or sea that was
created by the erosion of waves.

13.  SEA ARCHES: A sea arch is a natural opening eroded out of a
cliff face by marine processes. They are usually composed of a soft
rock that eroded over millions of years as waves hit land, carving
caves and tunnels in the rock.

14. SEA CAVES : formed in a cliff by wave action of an ocean or lake. Sea caves occur on
almost every cliffed headland or coast where the waves break directly on a rock cliff
and are formed by mechanical erosion rather than the chemical solution process.
BLUE GROTTO : is a sea
cave on the coast of
the island of Capri,
southern Italy.
Sunlight, passing
through an underwater
cavity and shining
through the seawater,
creates a blue
reflection

15. SEA STACKS : is a geological landform consisting of a steep and often vertical
column or columns of rock in the sea near a coast, formed by wave erosion.
Stacks are formed over time by wind and water, processes of coastal
geomorphology
THE TWELVE APOSTLES
are large limestone stacks which were
formed as a result of erosion by rain,
winds and wild seas. They are located
along the spectacular Great Ocean
Road in Victoria, Australia

16. SEA STUMP: Sea Stacks will be attacked at the base in the same way that
a wave-cut notch is formed. This weakens the structure and it will eventually
Collapse to form a stump
Sea Stump Great Pollet Sea Arch in County Donegal, Ireland.

22. BEACHES: Beaches are a common feature of a coastline. It is a landform along
a body of water. It usually consists of loose particles, which are often composed
of rock, such as sand, gravel, shingle, pebbles, or cobblestones.

23. BAR: A bar is very similar to a spit. If a spit joins one part of the mainland
to another it is called a bar. It is a ridge of sand or shingle which forms across
the mouth of a river, the entrance to a bay or harbour. It is usually parallel
to the coast.
Orford Ness is a foreland shingle spit on the Suffolk coast in Great Britain.

24. BARRIER : Barrier islands are coastal landforms and a type of dune system
that are exceptionally flat or lumpy areas of sand that form by wave and tidal
action parallel to the mainland coast. They usually occur in chains, consisting
of anything from a few islands to more than a dozen.

25. SPIT : A Spit is a long,
narrow ridge of deposited
materials that extends
from the mainland into the
sea.

26. TOMBOLO : When the spit is connected the island to the mainland to form
a feature is called the Tombolos.

27. RIDGE AND RUNNELS: Areas of the foreshore that are raised above the
adjacent shore which dips into a RUNNE. The cross section is similar to the hills
and valleys. They are formed due to the interaction of tides , currents, sediments
and the beach topography. They will only form on sallow gradient
Beaches
Ridges and runnels on Harlech beach, North Wales

28.  SAND DUNE: A sand dune is an accumulation of sand formed by the wind,
by waves and by eroding sandstone. Because dunes are dependent on the ever
constant forces of wind and water their structure is constantly changing.
Formby Coast, Merseyside in England

29. BLOWOUTS : is commonly occur in the foredune or within and on older vegetated
dunes. They are erosional dune landforms that are typically trough-, bowl-, or saucer-shaped
depressions or hollows formed by wind erosion of a pre-existing sandy substrate or dune

30. PARABOLIC DUNES: Continued transport of sand through blowouts often results
in the development of parabolic dunes.

32. SALT MARSH :A salt marsh is a coastal marsh that forms on mud flats.
They usually form in very sheltered inlets and estuaries, or behind spits
Salt marsh in CALIFORNIA

33. BEACH CUSP: 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
worldand are most noticeable on shorelines with coarsersediment such as
pebble beaches.

34. LAGOON: area of relatively shallow, quiet water situated in a coastal enviro-
nment and having access to the sea but separated from the open marine conditions
by a barrier. The barrier may be either a sandy or shingly wave-built feature
(such as a sandbar or a barrier island), or it may be a coral reef.

35. WASHOVER FANS : A fan-like landform of sand that washed over a barrier
island or spit during a storm, and then deposited sand on the landward side.
Washover fans can be small and completely subaerial—or they can be quite
large and include subaqueous margins that extend into adjacent lagoons

36. BEACHBERMS : are commonly found on beaches that have fairly coarse
sand and are the result of the deposition of material by low-energy waves.
On broad beaches there may be three or more subparallel berms , each
formed under different wave conditions. On some beaches a berm several
metres wide may be laid down each summer and destroyed each winter
by high storm waves.