Russia's Claim in the Arctic and the Vexing Issue of Ridges in UNCLOS

On August 2, 2007, Russian explorers in a submersible planted their national flag on the seabed below the North Pole in symbolic support of Russia's 2001 claim relating to its extended continental shelf. This claim was first made on December 20, 2001 in the context of Russia's submission to the UN Commission on the Limits of the Continental Shelf (CLCS) in accordance with Article 76(8) of the United Nations Convention on the Law of the Sea (UNCLOS). In this submission, one of the central claims of Russia was that parts of underwater mountains underneath the Pole - the Lomonosov and the Mendeleev Ridges- are in fact extensions of the Eurasian continent. In 2002, the CLCS neither rejected nor accepted the Russian submission, recommending carrying out additional research. Russia hopes that its latest geological "findings" about these ridges will produce a different outcome when the Commission next meets, in 2009.

The Insufficiency of the "Natural Prolongation" Criterion for Answering Russia's Claim[1]

Article 76(1) of UNCLOS defines the continental shelf by reference to two alternative basis for entitlement: 200 nautical miles distance from the coast or "natural prolongation," if a country wants to claim an extended continental shelf beyond 200 nautical miles. The latter basis is the one being advocated by Russia.

Article 76(1) of UNCLOS provides that the "continental shelf of a coastal State comprises the seabed and the 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." Therefore, according to this definition, as long as the natural prolongation criterion is satisfied, the continental margin is in fact the continental shelf. The continental margin is, for its part, defined in Article 76(3) as consisting of the seabed and subsoil of the shelf, the slope, and the rise. One can visualize an idealized continental margin / continental shelf as beginning with a relatively shallow extension of the landmass, the so-called geographical shelf, to a point where there is a drop-off into the oceanic abyss. The drop-off begins by a "slope" followed at further depth by a "rise". (See Figure 1)

The International Court of Justice (ICJ) has considered the concept of natural prolongation in the context of the definition of the continental shelf contained in Article 76(1) in the Tunisia/Libya Continental Shelf case and the Libya/Malta Continental Shelf case. In both instances, the ICJ indicated that natural prolongation may be defined by reference to either the geology or geomorphology of the seabed.[2]

However, the fact that a zone of the seabed is the natural prolongation of the land territory of a country means only that it has the potential to be included in the continental shelf of a country. In other words, the "natural prolongation" nature of a zone is a necessary but not a sufficient condition for its legal inclusion in the continental shelf. This is so because Article 76(2) of UNCLOS states that "the continental shelf of a coastal State shall not extend beyond the limits provided for in paragraphs 4 to 6 [of Article 76]". Therefore, as indicated by Article 76(4) (a), these limits are the way to determine the "outer edge of the continental margin" referred to in Article 76(1). As a result, "the application of these [limits] may place a part of the natural prolongation of the land territory beyond the outer limits of the continental shelf."[3] Thus, the natural prolongation criterion is insufficient to answer claims relating to the breadth of the continental shelf.

The first limit to this breadth is stipulated in Article 76(4) which provides two formulas for establishing what one can call the Outer Limit Line (See Figure 2). Both formulas use as a point of departure the "foot of the slope", a physiographic feature on the surface of the sea floor separating the continental slope from the continental rise. From this foot of the slope, an outer limit of the continental shelf may be located based on either, whichever is the greater, a measurement of 60 nautical miles seawards, or the so-called sediment thickness line consisting of points where the underlying sediment thickness is one per cent of the distance to the foot of the slope.

The second limit to the breadth of the continental shelf appears in Article 76(5) and is relating to the maximum distance seaward (See Figure 3) that this outer limit line can lie. As long as this maximum distance is respected, the outer limit line is equivalent to the "outer edge of the continental margin." This maximum distance, which could be called the "outer constraint line", is determined through two possible rules used alone or in combination, whichever is the greater. The first rule consists in drawing a line 100 nautical miles seaward of the 2500 meters isobath which connects the depth of 2,500 meters. The second rule consists in drawing a line 350 nautical miles from the coast baselines.

It is in the context of the construction of this outer constraint line that the issue of underwater elevations arises since these elevations are submitted to a special regime.

The Vexing Issue of Ridges in UNCLOS

Articles 76(3) and 76(6) of UNCLOS use three different terms to refer to submarine elevations and it is presumable that these terms have separate meaning.

The first term, namely "oceanic ridges", appears without any definition in Article 76(3). The article provides that "the continental margin . . . does not include the deep ocean floor with its oceanic ridges or the subsoil thereof." There is a direct link between oceanic ridges and the outer constraint line, since it is indicated that these oceanic ridges are beyond the outer constraint line and therefore are deemed not to be part of the continental shelf.

The second term, namely "submarine ridges", appears also without any definition in Article 76(6) of UNCLOS. In contrast with oceanic ridges, Article 76 (6) implies that parts of these submarine ridges could be included in the continental shelf and are thus by definition a "natural prolongation" of the land territory. However, on these parts, "the outer limit of the continental shelf shall not exceed 350 nautical miles from the baselines from which the breadth of the territorial sea is measured," even if these parts of the submarine ridges satisfy the 2500 meters isobath + 100 miles formula. Therefore, no parts of submarine ridges included in the continental shelf can extend beyond 350 nautical miles from the coastline.

Finally, the third term, namely "submarine elevations", appears also in Article 76(6) followed by the qualification "that are natural components of the continental margin such as its plateaux, rises, caps, banks and spurs." Not only can these submarine elevations be included in the continental shelf and are thus a natural prolongation of the land territory, but for them there is no 350-mile outer limit constraint. Points on these submarine elevations beyond 350 miles from the coastline could be included in the continental shelf, as long as they satisfy the 2500 meters isobath + 100 miles formula.

Under what Previous Provisions are Parts of Lomonosov and the Mendeleev Ridges Claimed by Russia?

Given the confidentiality of CLCS submissions and deliberations, there is no way to know precisely what provisions Russia invoked in 2001 or, for that matter, might invoke in a 2009 submission. However, while the "natural prolongation" doctrine is likely to play an important role in the discussion, it is unable, by itself, to give complete legal answers.

Russia's claim relating to parts of the Lomonosov and Mendeleev ridges is not based on the "oceanic ridges" clause. By definition, parts on oceanic ridges cannot be included in the continental shelf. Therefore, a conclusion that these parts are on "oceanic ridges" would mean that the debate is closed since these parts would then be beyond national jurisdiction.[4] In its reaction to the 2001 Russia's submission, the United States adopted this view for both the Mendeleev and the Lomonosov ridges. With regard for example to the Lomonosov ridge, the United States stated that this "ridge is a free standing feature in the deep oceanic part of the Arctic Ocean Basin, and not . . . a component of the continental shelf of either Russia on any other state."[5]

Russia may invoke the "submarine ridges" clause as the basis for its claim on parts of the ridges. There are, however, reasons to doubt that Russia adopted this approach in 2001 or that it would adopt it in 2009. The most significant piece of evidence is the absence in the geographic maps[6] accompanying Russia's 2001 submission, which would include indications about the distance of the claimed ridge points from the baselines of Russia's coastlines. If Russia's claim was based on the "submarine ridges" clause, it likely would have felt the need to give this distance since it knew that Article 76(6) forbids the use of points on submarine ridges beyond 350 miles from the baselines of its coast.

This leaves the possibility that Russia claims that parts of the ridges are in fact "submarine elevations that are natural components of the continental margin." This position would remove the 350 miles outer line constraint for its claimed ridge points as long as these points satisfy the 2500 meters isobath + 100 miles formula. This position would be similar to the one adopted by the United States concerning the Chukchi plateau off Alaska's north coast. The United States takes the position that features such as the Chukchi plateau and its component elevations, situated to the north of Alaska, are covered by the "submarine elevations" exemption, and thus are not subject to the 350 miles limitation set forth in Article 76 (6) of UNCLOS.[7] According to the International Law Association Committee on the Continental Shelf, the fact that the term "submarine elevations" in Article 76(6) is followed by the qualification "that are natural components of the continental margin", indicates that those elevations can be distinguished as separate features, but at the same time are closely linked to the continental margin. This is the case for features, which at some point in time were not a part of the continental margin or have become detached from the continental margin and have, through geological processes, become or remained so closely linked to the continental margin as to become or remain a part of it." [8]

Apart from general affirmations relating to the "natural prolongation" doctrine, and due in part to the confidential nature of submissions to the CLCS, there is at the moment much uncertainty on the exact provisions which are in fact invoked by Russia in its extended continental shelf claim. The most likely provision is the "submarine elevations that are natural components of the continental margin." However, since neither the expressions "submarine elevations" nor "natural components" are defined in UNCLOS, it is possible that the UN Commission on the Limits of the Continental Shelf would find itself in a situation where it would have to "legislate" implicitly in order to settle Russia's claim.

About the Authors
Marc Benitah, an ASIL Member, is Professor of International Law at the University of Quebec, where he teaches the Law of the Sea. He may be contacted at marc_benitah@uqar.qc.ca.

Footnotes