A continental shelf is the edge of a continent that lies under the ocean which
extends from the coastline of a continent to a drop-off point called as shelf
break.[i] A continental shelf holds a great significance for any coastal state
because of the fact that it holds many vital natural resources.
As a consequence,
there has been a need for the development of law at the international level
relating to continental shelf or otherwise different countries of the world
might have occupied large portions of the sea-bed and incorporated them into
their territory. Accordingly, continental shelves have been included under
International law which confirms as well as delimits each coastal state’s right
to explore and exploit the natural resources of continental shelf.
conventions, namely, the Geneva Convention, 1958 and the U.N. Convention on
the Law of the Sea, 1982 (UNCLOS) have played the fundamental role in the
shaping of International law with respect to continental shelves. And the U.N.
Convention on the Law of the Sea is also the present law on this point,
regulating the exploration and exploitation of natural resources of continental
Meaning and structure of Continental shelf
To define, continental shelf is a broad, relatively shallow submarine terrace of
continental crust forming the edge of a continental landmass. Stating simply,
continental shelf is the area of seabed around a large land mass where the sea
is relatively shallow compared with the open ocean. The continental shelf is
geologically part of the continental crust and shelf seas occupy about 7% of the
area of the world’s oceans, the majority of the world's continental shelf still
being unknown and unmapped.
However, a continental shelf is of national importance not just in the
geographical sense, but also in the legal, social and economic sphere because it
has abundance of natural resources; it being formed of both organic and
inorganic materials accumulated over millions of years.
Regarding the structure, a continental shelf typically extends from the coast to
depths of 100–200 metres (330–660 feet). It is gently inclined seaward at an
average slope of about 0.1°. In nearly all instances, it ends at its seaward
edge with an abrupt drop called the shelf break. Below this lies the continental
slope, a much steeper zone that usually merges with a section of the ocean floor
called the continental rise at a depth of roughly 4,000 to 5,000 metres (13,000
to 16,500 feet).[ii]
Historical Development of Legal Regime of Continental Shelf
States have always attached great importance to sea due to two important reason,
- the natural resources of the sea, and
- from the point of view of national security.
Talking about continental shelf, it too has both the
above-mentioned significance. However, though the geographical and geological
concept of continental shelf is quite an old one, the legal concept of
continental shelf was brought forward by the Gulf of Paria Treaty ,1942 and
brought into limelight by the Truman Proclamation of 1945.
The reason for the same being that the concept of continental shelf is
essentially related to the exploration of the natural resources from the sea
adjacent to the territorial sea. It was thus, not of much importance until the
exploration of marine natural resources became technically possible. Until the
first quarter of the twentieth century, the submarine areas remained widely
unexplored. But due to the progress made in marine technology and the
understanding of man of the land under the oceans, the exploration of continental
shelves began and gradually enhanced to a great extent during Second World War.
Subsequently, the United Kingdom and United States, although acting
independently, initiated a new legal regime of continental shelf for the
exploration of mineral and other resources in continental shelves Their
initiatives in this regard can be summarised as below:
The Gulf of Paria Treaty, 1942 This treaty was initiated by the United Kingdom with Venezuela. It was the first
conscious effort to establish rights or simply control over a large area of
sea-bed beyond the territorial waters, that is, continental shelf. In 1936, the
Foreign Office of the United Kingdom instructed its embassy in Venezuela to
negotiate with the host government in order to arrive at an agreement to delimit
the sea-bed and sub-soil of the Gulf of Paria whichis surrounded by the coast of
Venezuela and the island of Trinidad. Under it the parties agreed to recognise
each other’s rights and control which had been or might hereafter be lawfully
acquired, over the specified parts of the submarine area of the Gulf. The treaty
referred solely to the submarine areas of the Gulf and clearly mentioned that
nothing in the treaty would affect the legal status of the island, islets or
rocks above the surface of the sea together with the territorial waters thereof.
Lastly, it is worth noticing that the treaty had not used the term continental
shelf nor employed any criteria for delimiting frontiers of the annexed areas.
It did not indicate the basis on which the areas had been claimed by the
parties. But from the provisions of the treaty, it would be inferred that the
limits of territorial waters adjacent to the coast could be acquired by
occupation, provided that such occupation did not impinge upon the status of
waters above the submerged land.The treaty had thus, used the occupation-theory
in support of claiming larger areas of the sea-bed. [iii]
The Truman Proclamation, 1945
In 1943, the Secretary of the Interior of United States communicated to
President Roosevelt for emphasizing the importance of the continental shelf
extending some 100 to 150 miles from the shore, to the United States from the
point of view of security as well as natural resources. Accordingly, he
suggested the laying of a legal regime for full appropriation of the immense
natural resources of the continental shelf. Ultimately on September 28, 1945,
President Truman signed a Proclamation on the policy of United States with
respect to the Natural Resources of the Sub- soil and Sea-bed of the continental
It laid down that the Government of the United States regards the continental
shelf beneath the high seas but contagious to the coasts as a part of the United
States and thus, subject to its jurisdiction and control. But in cases where the
continental shelf extends to the shores of another state or is shared with an
adjoining state, the boundary shall be determined by the United States and the
state concerned according to equitable principles. Further it clearly provided
that the legal status of high seas and the right to their free navigation are in
no way affected by the treaty.
To sum up, like the Gulf of Paria Treaty, this Proclamation too had some
inherent defects, the major one being that it did not lay down any criteria for
delimiting the frontiers of the submerged areas, between the states concerned
and the basis on which such areas could be claimed by the parties. But a
subsequent U.S. State Department press release defined continental shelf as
submarine land which is contagious to the continent and which is covered by no
more than 100 fathoms of water. [iv]
The Geneva Convention on Continental Shelf, 1958
Encouraged by the said treaty and proclamation certain other states made similar
proclamations, for example, Mexico in 1945, Argentina in 1945, Chile in 1947 and
Peru, etc. These proclamations necessitated that a definite shape and form
should be given to the International Law relating to the continental shelf as it
was feared that in the absence of definite International Law on the point
different countries of the world might occupy large portions of the sea-bed and
incorporate them into their territory. Thus, in order to develop, codify and
enforce definite rules of International Law relating to continental shelf and
other aspects of the law of sea a conference was called at Geneva in 1958 and as
a consequence a convention called as the Convention of Continental Shelf, 1958
Stating briefly, apart from defining and delimiting the boundaries of a
continental shelf, the Geneva Convention through its various provisions seeks to
establish a balance between the rights of the coastal states over their
continental shelf and those of other states making use of the high seas for the
purpose of navigation, fishing, etc. with a view to avoid or minimise the
conflicts arising out of the competing use of the sea. It does not confer any
rights on the other states but it requires the latter to ensure certain
facilities to the former in connection with free navigation, fishing, laying of
submarine cables on the continental shelf and conducting scientific research
into the biological or physical characteristics of the continental shelf.
Article 1 of the convention defines continental shelf as follows:
Continental shelf refers to-
- to the seabed and subsoil of the submarine areas adjacent to
the coast but outside the area of the territorial sea, to a depth of 200metres
or, beyond that limit, to where the depth of the superjacent waters
admits of the exploitation of the natural resources of the said areas;
- to the seabed and subsoil of similar submarine areas adjacent to the
coasts of islands.
Criticism of the Definition:
The above definition providestwo alternative criteria for defining the area of
continental shelf, namely, depth of the sea criteria and exploration criteria.
The first criterion is that the continental shelf extends to a depth of 200
metres of the sea because at that time it was thought that exploration of
natural resources was not possible beyond this depth from coasts. However, the
criterion was not rigid and where the exploitation of resources could be made
beyond that limit, that area could also be referred to as continental shelf on
the basis of the exploitation criteria.
And the developed statesapplied the exploitation criteria. Thus, if the above
definition is accepted a large part of the sea would become part of the
continental shelf and the International Relations would be burdened with new set
of conflicts. Accordingly, there was a need for a more definite and elaborate
law on the point and now the law in this regard is laid down by the U.N.
Convention on the Law of Sea, 1982. [v]
The U.N. Convention on the Law of Sea, 1982 (UNCLOS)
UNCLOS has been ratified by 153 nations and is in force since 1994. It specifies
under Article 76 national obligations, rights, and jurisdiction over continental
shelf up to at least 200 nautical miles or to a maritime boundary. And further,
it contains provisions enabling the coastal states to establish their
continental shelves beyond 200 nautical miles also, but, according to and
subject to the conditions given therein. To date, seven submissions for extended
continental shelves (ECS) have been filed under UNCLOS (Annex II).
Before, looking into the specific provisions of the convention relating to
continental shelf it isworth mentioning that they have been influenced by and
are largely based on the decision of the International Court of Justice in the
North Sea Continental Shelf Case (1969). In this case the Court had observed
the rights of the coastal state in respect of the area of continental shelf
that constitutes natural prolongation of its land territory into and under the
sea, exist ispo facto and ab initio by virtue of its sovereignty over the land
and as an extension of it in exercise of sovereign rights for the purpose of
exploring the sea-bed and exploiting its natural resources. Here, there is an
inherent right of the coastal state.
The Court further held, what confers
the ispo jure title with International Law, which attributes to the coastal
states in respect of continental shelf, is the fact that submarine areas may be
deemed to be actually part of the territory over which the coastal state has
already dominion in that sense that although covered with water, they are a
prolongation or continuation of that territory, an extension of it under the
Definition of Continental Shelf
Article 76 of the convention thus, defines continental shelf as follows:
The continental shelf of a coastal State comprises the seabed and subsoil of
the submarine areas that extend beyond its territorial sea throughout the
natural prolongation of its land territory to the outer edge of the
continental margin, or to a distance of 200 nautical miles from the
baselines from which the breadth of the territorial sea is measured where
the outer edge of the continental margin does not extend up to that
Thus, the above definition incorporates in the first part, the concept of
continental shelf as highlighted by the International Court of Justice in the
North Sea Continental Shelf Case, and in the second part provides for a uniform
continental shelf up to a distance of 200 nautical miles to those coastal states
which have a short continental shelf and their continental shelf does not extend
to the said distance. Therefore, the convention has set at rest the controversy
as to the definition of continental shelf.
- Outer Limits of Continental Shelf
Paragraph 4(a) of Article 76 of U.N Convention on the Law of the Sea,
"For the purposes of this convention, the coastal State shall establish the
outer edge of the continental margin wherever the margin extends beyond 200
nautical miles from the baselines from which the breadth of the territorial sea
is measured, by either:
(i) A line delineated in accordance with paragraph 7 by references to the
outermost fixed points at each of which the thickness of sedimentary rocks is at
least 1 per cent of the shortest distance from such point to the foot of the
continental slope; or
(ii) A line delineated in accordance with paragraph 7 to fixed points not more
than 60 nautical miles from the foot of the continental slope."
So, Paragraph 4(a) lays down the method of establishing the outer edge
of the established continental margin or in simpler terms, the seaward boundary
of the continental shelf beyond 200 nautical miles. Further, the convention also
lays down the formula for fixing the precise limits of the Continental Shelf of
a coastal state in Paragraph 5 of Article 76 in the following words:
"The fixed points comprising the line of the outer limits of the Continental
Shelf on the sea bed, drawn in accordance with paragraph 4(a) (i) and (ii),
either shall not exceed 350 nautical miles from the baselines from which the
breadth of the territorial sea is measured or shall not exceed 100 nautical
miles from the 2,500 metres is obath, which is a line connecting the depth of
A State C’s Exploration Ship discovers oil below the depth of 1500 metre in the
Seabed at a distance of 190 miles from the Indian coast. India claims that she
has exclusive rights to exploit and use this oil. The question which arises is
whether India’s claim is justified or not. India's claim is justified
because as for definition of continental shelf in Article 76 of the Convention
the continental shelf of a coastal State extends to the edge continental margin
or 200 nautical miles where the outer edge of the continental margin does not
extend upto that distance.
Moreover, outer limit of the continental shelf may be upto 350 nautical miles from the baselines or may not exceed 100 nautical miles
from the 2,500 metres isobath. Since 'C' State has discovered oil below the
depth of 1500 metres in the Seabed at a distance of 190 miles from the Indian
coast, it is clearly within the continental shelf of India. [vii]
- Commission on the Limits of the Continental Shelf
The Convention also establishes a Commission on the Limits of the Continental
Shelf. Paragraph 8 of the Article 76 of the Convention provides that information
on the limits of the Continental Shelf beyond the 200 nautical miles from the
baselines (which is dealt by paragraph 4(a), paragraph 5 and paragraph 7) shall
be submitted by the coastal state to the Commission on the Continental Shelf set
up under Annex II and the work of the Commission is to make recommendations to
the coastal state on matters related to the establishment of the outer limits of
their Continental Shelf. Lastly,the limits of the shelf established by a coastal
state on the basis of these recommendations shall be final and binding.
The detailed provisions relating to the Commission are contained in Annex II of
the Convention. Article 1 of Annex II provides thata commission on the limits
of the Continental Shelf beyond 200 nautical miles in accordance with Article 76
shall be established. Article 4 of Annex II provides that the concerned coastal
stateshall submit particulars of extended boundary to the Commission along with
supporting scientific and technical data as soon as possible but within 10 years
of the entry into force of this convention for that State.
Further according to Article 6 of Annex II the Commission shall consider data
and other material submitted by coastal states and then make recommendations in
writing to the coastal state which made the submission and to the
Lastly, Article 8 of Annex II provides that in case of
disagreement of the coastal state with recommendations made by the Commission,
the coastal state shall, within reasonable time make a revised or a new
submission to the Commission.
North Sea Continental Shelf Case (1969)
Article 6(2) of the Geneva Convention, 1958 provides:
where the same Continental Shelf is adjacent to the territories of two adjacent
states, the boundary of the Continental Shelf shall be determined by agreement
between them. In the absence of agreement, and unless another boundary line is
justified by special circumstances, the boundary shall be determined by
application of the principle of equidistance from the nearest points of the
baselines from which the breadth of the territorial sea of each state is
And in the North Sea Continental Shelf Case (1969)the International Court of
Justice considered this principle of equidistance in such a remarkable manner
thatthe Court’s judgement will long be remembered for its classical exposition
of the principle governing delimitation of continental shelf between two or more
- Detailed Analysis of the Case
Germany’s North Sea Coast is concave, whereas, Netherlands’ and Denmark’s Coasts
are convex. When a dispute arose between these states regarding the delimitation
of their continental shelf both Denmark and Netherlands relied on a multilateral
treaty among them and Germany which provided for delimitation by the
The treaty permitted the signatory states to reserve their position with respect
to the equidistance method. Germany had signed the treaty but had not ratified
it and moreover, it had reserved its position with respect to delimitation by
the equidistance method, which might have adversely affected its own continental
Further, it was contented by Denmark and Netherlands that the configuration of
the German North Sea coast did not amount to ‘special circumstances ‘as
mentioned in Article 6(2) of the Geneva Convention, 1958 and thus, the
delimitation must be according to the equidistance method. They even maintained
that the method has emerged into a custom also and thus was binding on Germany.
Germany rejected the obligatory character of the method, as a custom, on the
ground of absence of opinion juris on its part. Further, it contended that the
different configuration of its coast amounts to special circumstances under the
above-mentioned article. Thus, the correct rule for delimitation of the
continental shelf is one according to which each state gets a just and equitable
share of the continental shelf, in proportion to the length of its coast line or
- Judgement of the Case
By majority of eleven votes to six, the World Court finally held that the use of
the equidistance method of delimitation was not obligatory between the parties
of the case; and thus, there being no single method of delimitationthe use of
which is in all circumstances obligatorythe principles applicable to the parties
in this case are as follows:
(1) Delimitation is to be affected by agreement in accordance with
equitable principles, and taking into account of all the relevantcircumstances,
in such a way to leave as such possible to each party allthose parts of the
Continental Shelf that constitute a naturalprolongation of its land territory
into and under the sea, withoutencroachment on the natural prolongation of the
land territory of the other;
(2) if in the application of the preceding sub-paragraph, the
delimitation leaves to the parties areas that overlap, these are to be divided
between them in agreed proportions, or failing agreement, equally, unless they
decide on a regime of joint jurisdiction, user or exploitation for the zones of
overlap or any part of them;
(3) in the course of negotiations, the factors to be taken into account are to
(a) the general configuration of the coasts of the parties as well as the
presence of any special or unusual features;
(b) so far as known or readily ascertainable the physical and geological
structure and natural resources, of the Continental Shelf areas involved;
(c) the element of a reasonable degree of proportionality, which a
delimitation carried out in accordance with equitable principles ought to bring
Being influenced by the above decision of the International Court of
Justice, Article 83 of the U.N. Convention on the Law of the Sea, 1982, provides that delimitation
of Continental Shelf between states with opposite or adjoining coasts shall be
made by agreement on the basis of international law, as referred to in Article
38 of the Statute of the International Court of Justice, in order to achieve an
In case no agreement can be reached within a reasonable period of time, the
states concerned shall resort to the procedure provided under Part XV dealing
with the Settlement of Disputes. And during the pendency of the settlement,
the states concerned in spirit of understanding and co-operation, shall make
every effort to enter into provisional arrangements of a practical nature, and,
during this transactional period, not to jeopardise prejudice to the final
Where there is an agreement in force between the states concerned, questions
relating to the delimitation of Continental Shelf shall be determined in
accordance with the provision of that agreement.
Thus the 1989 Convention does not at all mention the principle of equidistance.
It emphasizes agreement between the parties. However, parties "in order to
achieve an equitable solution" may take into account the principle of
Significance of the U.N. Convention on the Law of Sea, 1982 (UNCLOS) in the present time
The Convention is playing a very significant role in international relations
with the increasing significance of continental shelves, in the sense that the
coastal states are now more and more willing to explore the shelf areas for
exploiting their natural resources.
The Convention lays down various rights of the coastal states in respect of
continental shelf areas
, the most important provision of the Convention being
the one relating to delimitation of continental shelf.
The area of continental shelf cannot be appropriated by the coastal states, and
therefore, they cannot exercise sovereignty over it. However, the states may
exercise sovereign rights over it for the purposes of exploring it and
exploiting its natural resources upto 200 nautical miles.
Also, according to Article 76
of the Convention the coastal states may determine
the outer limits of the continental shelf as well, in accordance with and
subject to the limitations given therein.
In this regard Article 82
provides that those coastal states which exploit the non-living resources of the
continental shelf beyond 200 nautical miles are required to make payments or
contributions in kind to the International Sea-bed Authority. And the rate of
payments and contributions shall be according to Article 83, and be made
Another important provision is laid down under Article 77 which provides that
the above rights of exploring and exploiting are exclusive. It means that if the
coastal state does not explore the continental shelf or exploit its natural
resources, no other state cancarry out these activities without its express
Article 81 also provides that the coastal states shall have the exclusive right
to authorise and regulate drilling on the continental shelf for any purposes.
And according to Article 85 they have a right to exploit the subsoil by way of
tunnelling, irrespective of the depth of water above the subsoil.
Apart from the rights of the coastal states, the Convention makes some
provisions for the rights of the other states as well.
- Firstly, Article 78 maintains that the above rights of the coastal
states over the continental shelf do not affect the legal status of the
superjacernt waters or of the air space above them.
- Secondly, the exercise of the right of the coastal states over the
continental shelf must not infringe or result in any unjustifiable
interference with navigation rights and freedom of other States.
Thus, coastal States are entitled only to construct and operate the necessary
installations within their continental shelf in accordance with these
safeguards. Further, the other states are entitled to lay submarine cables and
pipelines on the continental shelf. But the right can be exercised only with the
consent of the coastal states. The coastal State for giving consent of giving
may impose conditions for cables or pipelines.
Indian Position on Continental Shelf
Indian position on continental shelf has been made clear under Section 6 of the
Maritime Zones Act of 1976. Part 1 of the above Section lays down that the
continental shelf of India comprises:
"the sea-bed and subsoil of the sub-marine areas that extend beyond the limit of
the territorial waters throughout the natural prolongation of its land territory
to the outer edge of the continental margin or to a distance of 200 nautical
miles from the baseline….where the outer edge of the continental margin does not
extend up to that distance."
The Act also laid down under Section 6, Para 3:
The Union has:
- sovereign rights for the purposes of exploration, exploitation,
conservation and management of all resources;
- exclusive rights and jurisdiction for the construction, maintenance or
operation of artificial Islands, off-shore terminals, installations and
other structures and devices necessary for the continental shelf or for
convenience of shipping or any other purpose;
- exclusive jurisdiction to authorise, regulate and control scientific
- exclusive jurisdiction to preserve and protect the marine environment
and to prevent and control marine pollution.
It is further provided that no person (including a Foreign Government) shall,
except under, and in accordance with, the terms of licence or a letter of
authority granted by the Central Government, explore the continental shelf or
carry on any search or drill therein or construct or conduct any research with
the continental shelf or drill therein or construct, maintain or operate any
artificial Islands, off shore terminals, installations or other structure or
device therein for any purpose.
Thus, the Indian position is consistent with the provisions of the U.N.
Convention on the Law of the Sea, 1982.
The geographical concept of continental shelf is an old one but the legal regime
regarding continental shelves at the International level is of quite a recent
origin. It started from the Gulf of Paria Treaty ,1942, followed by the Truman
Proclamation of 1945. Then the Geneva Convention of 1958 was a major convention
on this point but it had some inherent defects, particularly in the definition
of continental shelf, provided under the Convention.
At present, the law relating to continental shelf is provided by the U.N.
Convention on the Law of Sea, 1982. Also, the remarkable judgement of the
International Court of Justice in the North Sea Continental Shelf Case (1969)
laid down some very important rules rather guidelines for the delimitation of
Further, it is worth mentioning that the U.N. Convention on the Law of Sea, 1982
is a very comprehensive one, dealing with all the aspects of continental shelf
delimitation, the various rights of the coastal states as well of the other
Thus, it not only seeks to avoid conflicts among the coastal states but also to
strikes a balance between the rights of the coastal and other states. To sum up,
it can be stated that the adoption of the continental shelf concept has been so
rapid, due to the natural resources of continental shelf as well as from the
point of view of security of the coastal states also, that the U.N. Convention
on the Law of Sea has acquired an important place in the sphere of International
- Continental Shelf, available at:https://www.nationalgeographic.org/encyclopedia/continental-shelf/
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- Continental Shelf, available at: https://www.britannica.com/science/continental-shelf
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- S.P. Gupta, International Law and Human Rights 158 (Allahabad Law
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- S.K. Kapoor, International Law & Human Rights 265 (Central Law Agency,
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- Dr. H.O. Agarwal, International Law & Human Rights 140 (Central Law
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- I.C.J. Reports (1969), p.3.
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- I.C.J. Reports (1969), p.3.