A seminar on Coastal Landforms.

1. A Seminar On
Coastal Landforms
GUIDED BY:- SUBMITTED BY:-
Dr. S.N. Mohapatra Pratyush Kumar Mohanta
S.O.S Earth Science M.Sc. 1st Semester
Jiwaji University, Gwalior

2. Contents
Introduction
Factors and Forces in the Formation Of Coastal Features
Process Of Erosion
Landforms Of Coastal Erosion
Landforms Of Coastal Deposition
Coastal Landforms in India
Conclusion

3. COASTAL GEOMORPHOLOGY
Coastal Geomorphology is a branch of geology in
which the focus is on the area influenced by large
bodies of water, including seas and oceans, and large
lakes.
It includes understanding coastal weathering
processes, particularly wave action, sediment
movement and weather, and the ways in which
humans interact with the coast .

4. FACTORS AND FORCES IN THE FORMATION OF
COASTAL FEATURES
WAVES
RIP CUREENT
TIDES
CLIMATE RAINFALL
TEMPRATURE
WIND
GRAVITY

5. PROCESS OF EROSION
HYDRAULIC
ACTION
ATTRITION
ABRASION
SOLUTION

6. PROCESS OF EROSION
Hydraulic action:
Hydraulic action occurs when waves striking a cliff face compress air in cracks
on the cliff face.
This exerts pressure on the surrounding rocks and can progressively splinter
and remove pieces. Over time, the cracks can grow, sometimes forming a cave.
Attrition:
Attrition occurs when waves cause loose pieces of rock debris to collide with
each other, grinding and chipping each other , progressively becoming smaller,
smoother and rounder.

7.  Solution:
Solution is the process in which acids contained in sea water will dissolve
some types of rock such as chalk or limestones.
 Abrasion:
Abrasion also known as corrosion, occurs when waves break on cliff faces
and slowly erode it.
As the sea pounds cliff faces it also uses the from other wave actions to
batter and break off pieces of rock from higher up the cliff face which can
be used for this same wave action and attrition.
 Corrosion:
Corrosion occurs when the seas pH corrodes rocks on a cliff face.

8. LANDFORMS OF COASTAL EROSION
Headlands and Bays
Cliffs and Wave Cut Platforms
Sea Caves, Arches
Sea stacks, Stumps

9. HEADLANDS AND BAYS
 Headlands and bays are
landforms of coastal erosion.
 A headland is an area of land
that is surrounded by water
on three sides. Very often,
the land areas are called
capes.
 A bay is an area of water. It is
surrounded by land on three
sides .
 A bay is a large body of water
in the land next to a sea or
lake between two headlands

11. CLIFFS AND WAVECUT PLATFORMS
 Cliffs are steep or vertical slopes
that rise precipitously from the sea
or from a basal platform .
 About 80% of the world’s oceanic
coasts are edged with cliffs (Emery
and Kuhn 1982) .
 Cliff-base notches are sure signs of
cliff erosion .
 Wave -cut platform 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 .

14. SEA CAVES AND ARCHES
A sea cave, is a hollow excavated by waves in a
zone of weakness on a cliff.
The cave depth is greater than the entrance
width.
Sea caves tend to form at points of geological
weakness, such as joints and faults.
It is 20m high and 70m long .
Where powerful wave action has excavated
caves along joints and bedding planes on a
cliffed coast, some may extend through
headlands to form a natural arch.
Sea Cave
Sea
Arches

15. SEA STACK AND STUMPS
 A sea stack 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 process of coastal
geomorphology.
 A sea stump is formed when a tall sea stack is eroded and worn
down until it just above the surface of the sea.

17. Sea Stack Sea Stump

18. LANDFORMS OF COASTAL DEPOSITION
Beach
Bar and Barriers
Tombolo
Spit
Lagoons
Coastal Sand Dunes

19. BEACH
 Beaches are the most significant
accumulations of sediments
along coast.
 They are formed in the zone
where wave processes affect
coastal sediments.
 In composition, they consist of a
range of organic and inorganic
particle mostly sand, or pebbles.
 Pebble beaches are more
common at middle and high
latitudes where pebbles are
supplied by course glacial and
peri glacial debris.

20. BARS AND BARRIERS
 The ridge, embankments or mounds of sands formed by sedimentation
through sea waves parallel to the shore line are called Bars.
 The larger forms of bars are called Barriers .
 The formation of bars and barriers starts with the development of
shoals due to deposition of sands .

21. TOMBOLO
 Tombolos are wave-built ranges of beach material connecting islands to
the mainland or islands to islands.
 They come in single or double varieties .
 Chesil Beach in Dorset, England, is part of a double tombolo that attaches
the Isle of Purbeck to the Dorset mainland.
 Tombolos tend to grow in the lee of islands, where a protection is
afforded from strong wave action and where waves are refracted and
convergent.
 Y-shaped tombolos develop where comet-trail spits merge with cuspate
forms projecting from the mainland or where a cuspate barrier is
extended landwards or seawards.

22. Tombolo

23. SPITS
Barrier spits often form at the mouths of estuaries and other places where
the coast suddenly changes direction.
Sediments moving along the shore is laid down and tends to extend along
the original line of the coast.
Some spits project into the ocean and then curve round to run parallel to
the coast.
An example is Orfordness on the east coast of England, where the River
Alde has been deflected some 18km to the south.

24. Spits

25. LAGOON
 A lagoon is a shallow body of water
separated from a larger body of water
by reefs, barrier islands or a barrier
peninsula.
 Lagoons are commonly divided into
coastal lagoons and atoll lagoons.
 They have also been identified as
occurring on mixed-sand and gravel
coastlines.
 There is an overlap between bodies of
water classified as coastal lagoons and
bodies of water classified as estuaries.
 Lagoons are common coastal features
around many parts of the world.

26. Costal Sand Dunes
 Coastal dunes are heaps of wind
blown sediment deposited at the
edge of large lakes and seas.
 With few exceptions, they are made
from sediment blown off a beach to
accumulate in areas sheltered from
the actions of waves and currents.
 Small crescentic dune fields often
form at the back of bays enclosed by
rocky headlands, while larger
prograding dune fields form on
straight, sandy coasts that are
exposed to prevailing and dominant
onshore winds.
 Coastal dunes are mainly composed
of medium sized to fine quartz grains
that are well to very well sorted.

27. COSTAL LANDFORMS IN INDIA
• Beaches Found In India:-
 Puri Sea Beach in Odisha
 Beach in Mumbai Maharashtra
 Beach in Visakpatnam, Andhra Pradesh
 Lettuvellam Vembanad, Kerela

28. LAGOON IN INDIA
 Chilika Lake in Odisha (Worlds 2nd largest and Indias largest )
 Pulicat Lake in Tamilnadu
 Vembanad lake in Kerala
 Nizampatnam Lagoon in Andhra Pradesh
 Kaliveli Lake in Tamilnadu

29. SEA CLIFF IN INDIA
 Verkala Kerala
 Diu, Gujrat
 Meenakunnu Beach Kerala
 The highway Linking Panel and Goa
 Vagator Goa

30. Sea Caves and Sea Arches in
India
Bora caves Andhra Pradesh
Sea Arch in Neil Island, Andaman and Nicobar, India
Sea Stacks in India
 Sea stack at Saurashtra, Gujarat India

31. CONCLUSION
There are several other aspects coming under the coastal regions.
The classification of coasts, classification of beaches and
classification of shorelines are all very vast areas of study. All of them
are coming under the subject called Coastal Geomorphology . It is a
very interesting subject to learn.
There are hundreds of kinds of landforms existing in several parts of
the world . Let us try to understand them in the subject
geomorphology.

32. BIBLIOGRAPHY
 Coastal Geomorphology -An Introduction, Second
Edition- Eric Bird (1973)
 Fundamentals of Geomorphology - Second Edition
Richard Jhon Huggett

33. THANK YOU