International Court of JusticeFebruary 24, 1982

Ramirez, Princess L.Public International Law

2nd Semester, AY 2009-2010

Geographical Context

The FactsThe Republic of Tunisia and the Socialist People’s Libyan Arab

Jamahiriya are both situated on the northern coastline of the African Continent, fronting on the Mediterranean Sea.

While the Parties have not concluded any agreement delimiting any part of the continental shelf, this has not prevented a certain amount of exploration and exploitation. Each Party has granted concessions in respect of areas regarded by the Party concerned as appertaining to itself.

Tunisia had an existing concession line. In 1974, Libya granted a concession the boundary of which was a line drawn from Ras Ajdir at some 26° to the meridian, further west than the equidistance line, so the result was an overlapping of claims in an area some 50 miles from the coast.

Following protests in 1976 by each Government at the activities of the other, the Parties signed a Special Agreement in 1977 by which the matter was brought before the International Court of Justice.

The Dispute Libya and Tunisia requested the Court to:

A. Determine what principles and rules of international law may be applied for the delimitation of the area of the continental shelf appertaining to each of them;

B. Decide according to equitable principles, and the relevant circumstances which characterize the area, as well as the new accepted trends in the Third Conference on the Law of the Sea, and;

C. Clarify the practical method for the application of these principles to enable the experts to delimit these areas without difficulties.

Submission of the PartiesSubmission of the PartiesLIBYA TUNISIA

• A State is entitled ipso facto and ab initio to the continental shelf which is the natural prolongation of its land territory into and under the sea.

•Any delimitation should leave as much as possible to each Party all those parts of the continental shelf that constitute its natural prolongation.

•The delimitation should be effected in such a way, taking into account the physical and natural characteristics of the area, as to leave to each party all those parts of the continental shelf that constitute a natural prolongation of its land territory into and under the sea, without encroachment on the natural prolongation of the land territory of the other.

•The natural prolongation of the land territory of a State into and under the sea establishes its ipso jure title to the appurtenant continental shelf .

•The delimitation must not, at any point, encroach upon the area within which Tunisia possesses well-established historic rights

LIBYA TUNISIA

• For the purpose of achieving an equitable delimitation, the whole of the sea-bed and subsoil beyond the low-water mark along the coast of each Party is to be taken into account.

•The delimitation must be effected in conformity with equitable principles and taking account of all the relevant circumstances which characterize the case.

• Given the particular geographical configuration, the equidistance method would result in a delimitation of the continental shelf which would be inequitable, inappropriate, and not in conformity with international law.

•The delimitation should lead to the drawing of a line which would not appreciably depart from the lines which result from taking into account the geomorphological factors peculiar to the region, in particular the existence of a crestline determined by the Zira and Zuwarah Ridges,

Submission of the PartiesSubmission of the Parties

The Parties’ Delimitation MethodsTunisian methods

Tunisia has 2 kinds of methods:

The first group consists in defining the natural prolongation of the two States on the basis of geological, geophysical and bathymetric data

The second group is geometrical, based on the configurations of the coasts of the two States, with a view to implementing the concepts of the coastal front and of proportionality

Libyan method

Construct a line of delimitation which is consistent with the northward direction of the natural prolongation.

The Court’s RulingA. APPLICABLE PRINCIPLES AND RULES OF

INTERNATIONAL LAWThe delimitation is to be effected in accordance with

equitable principles considering all relevant circumstances.

The area relevant for the delimitation constitutes a single continental shelf as the natural prolongation of the land territory of both Parties, therefore principle of natural prolongation cannot be used.

In the particular geographical circumstances of the present case, the physical structure of the continental shelf areas is not such as to determine an equitable line of delimitation.

The Court’s RulingB. THE RELEVANT CIRCUMSTANCES TO BE

TAKEN INTO ACCOUNT IN ACHIEVING AN EQUITABLE DELIMITATION

The existing and potential delimitations with other states in the area -- the rights of third States are reserved

The general configuration of the coasts of the Parties, and in particular the marked change in direction of the Tunisian coastline

The existence and position of the Kerkennah IslandsThe land frontier between the Parties, and their conduct

prior to 1974 in the grant of petroleum concessions, resulting in the employment of a line seawards from Ras Ajdir, which had in the past been observed as a de facto maritime limit

The element of a reasonable degree of proportionality

The Court’s RulingC. THE PRACTICAL METHOD FOR THE

APPLICATION OF THE AFORESAID PRINCIPLES AND RULES

The Court reviewed and rejected the lines proposed by the parties. It held that a delimitation based on equitable principles, taking into account the relevant circumstances, called for the boundary area to be treated as two sectors, and it indicated a line of delimitation in two segments.

The Court’s RulingThe area is delimited by two lines:

Initial line – The Court took note of the de facto line employed by each Party dividing their petroleum concessions.

Second line – The change in direction of the coast was taken into account. The land territory of the two States is adjacent but because of the change in direction of Tunisia’s coast, it seems opposite at some point. In determining the angulation of this line, the existence of

Kerkennah Islands was considered. Causing the delimitation line to run parallel to the island

coastline would amount to giving excessive weight to the islands and would result in the diminution of the Libyan continental shelf

The Court’s Delimitation MethodStep 1: Determine the initial line

De facto line used by parties to divide their oil concessions

Step 2: Take note of the abrupt change in the coast’s direction

The Court identified the most westerly portion of the Tunisian coast

Step 3: The “Half-effect” MethodTo determine the angle of the second line, the Court employed the “half-effect” method. This involved drawing two delimitation lines:one giving to the island the full-effect attributed to it by the delimitation method in usethe other disregarding the island totally. The delimitation line actually adopted is drawn between the first two lines.

Line

1 (n

o ef

fect) Line 2 (fu

ll effect)

The Result

Legend: No effect / full effect Half-effect