On 14 December 2012, the People’s Republic of China (“China“) made a partial submission to the Commission on the Limits of the Continental Shelf (the “CLCS“) regarding the limits of its continental shelf beyond 200 nautical miles in the East China Sea.
China’s submission triggered an almost immediate response from both the Republic of Korea and Japan. On 26 December 2012, the Republic of Korea made a partial submission to the CLCS in the East China Sea that overlapped in part with China’s submission. Japan filed objections with the Commission to the submissions of China and the Republic of Korea on 28 December 2012 and 11 January 2013 respectively.
The East China Sea consists of an area of approximately 1,250,000 km2 and is reported to be rich in natural resources. It is bounded by China to the west, the Republic of Korea to the north, Japan to the east and the Republic of China (Taiwan) to the south. The continental shelf is only one of several questions in dispute between States regarding the East China Sea in addition to, for example, the issue of sovereignty over the islands known as the Diaoyu islands (in Chinese) or Senkaku islands (in Japanese).
The United Nations Convention on the Law of the Sea (“UNCLOS” or the “Convention“) sets out a regime of maritime zones which includes the territorial waters, Exclusive Economic Zone (“EEZ“) and continental shelf. UNCLOS has been ratified by 163 States and many of its provisions are considered as reflective of customary international law (i.e., binding upon all States, whether they have chosen to ratify the Convention or not).
Article 77(1) of UNCLOS provides that a coastal State: “exercises over the continental shelf sovereign rights for the purpose of exploring it and exploiting its natural resources”. Pursuant to Article 76(1) of the Convention, the continental shelf of a coastal State constitutes the seabed and subsoil of 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, alternatively, to a distance of 200 nautical miles from the coast where the continental margin falls short of 200 nautical miles.
Article 76(4) of the Convention sets out two methods by which the outer edge of the continental margin can be measured, both of which use the “foot of the continental slope” (the point where the gradient of the seafloor undergoes its maximum change) as the starting point. These are commonly known as the “Irish Formula” and the “Hedberg Formula”.
The “Irish Formula” delimits the margin by reference to the outermost points where the thickness of sedimentary rock is at least 1% of the distance between it and the foot of the slope. The alternative “Hedberg Formula” determines the limit of the shelf based on a line that falls 60 nautical miles from the foot of the slope. Both China and the Republic of Korea utilised the Hedberg Formula in calculating the outer limits of the continental shelf in the East China Sea in their partial submissions of December 2012.
Despite the comprehensive regime created by UNCLOS to determine the outer limits of the continental shelf, it appears unlikely that the CLCS will be able to take meaningful action in relation to the East China Sea; under its Rules of Procedure, the CLCS’ mandate does not extend to situations which involve a “land or maritime dispute”.
The CLCS was established by UNCLOS to resolve situations of uncertainty concerning the calculation of the limits of the continental shelf. Pursuant to Article 76(8) of the Convention, where a coastal State seeks to claim a continental shelf beyond 200 nautical miles, it must submit information on the limits of the continental shelf to the CLCS. Since 2001, CLCS has received over 60 submissions.
After receiving a submission, the CLCS has a mandate to make recommendations: “on matters related to the establishment of the outer limits of their continental shelf”. This can be a lengthy process, and it may take the CLCS several years to issue recommendations. Where a coastal State establishes the limits of the continental shelf on the basis of these recommendations, Article 76(8) of UNCLOS provides that the limits “shall be final and binding”. However, if the coastal State disagrees with the CLCS’ recommendations, UNCLOS provides that the State shall “within a reasonable time, make a revised or new submission to the Commission”.
China has made two submissions on the outer limits of the continental shelf beyond 200 nautical miles. China’s first submission was lodged on 11 May 2009. In its second submission of 14 December 2012, China extended its earlier submission by moving the outer limit of its continental shelf further toward the Republic of Korea.
In its second submission, China claims that the continental shelf off its coastline in the East China Sea extends to the Okinawa Trough. The Okinawa Trough is described by China in its submission as a “generally elongated depression” approximately 1,200 km in length and up to 150 km wide, with a maximum depth of 2,300 meters. It is located well within 200 nautical miles of Japan. China’s position is that the “geomorphic and geological features” of the Okinawa Trough are distinctly different from the continental shelf. China argues the continental shelf is comprised of “stable continental crust”, while the Okinawa Trough has been “transformed” into “transitional crust” by the upwelling of the upper mantle and thinning of the continental crust. The “prominent cut-off characteristics” of the Okinawa Trough are thus said by China to demonstrate that it is the “natural termination” of the continental shelf.
Following China’s submission of 14 December 2012, the Republic of Korea also made a second submission to the CLCS on 26 December 2012. In that submission, the Republic of Korea adopted a similar approach to China in defining the limits of the continental shelf, also claiming that the natural prolongation of the continental shelf off its coast extended to the Okinawa Trough. Thus, part of the Republic of Korea’s submission overlaps with that of China.
Again like China, the Republic of Korea’s second submission also extended to a larger area than in its previous 2009 submission (the Republic of Korea submitted its “Preliminary Information regarding the Outer Limits of the Continental Shelf” on the same day as China in 2009). The Republic of Korea’s first submission defined an outer shelf area extending to 19,000 km2 beyond its 200 nautical mile limit; its subsequent submission now identifies an outer shelf area over double that size.
On 28 December 2012, Japan issued a communication requesting the CLCS not to consider China’s submission. Japan highlighted that the distance between their opposing coasts was less than 400 nautical miles. It noted that, pursuant to Article 83 of UNCLOS, the delimitation of the continental shelf between States with opposite coasts is to be effected “by agreement on the basis of international law … in order to achieve an equitable solution.” Finally, Japan observed that the CLCS’ Rules of Procedure provide:
“In cases where a land or maritime dispute exists, the Commission shall not consider and qualify a submission made by any of the States concerned in the dispute. However, the Commission may consider one or more submissions in the areas under dispute with prior consent given by all States that are parties to such a dispute.”
For the avoidance of doubt, Japan expressly stated that it did not grant its consent to the consideration of China’s submission to the CLCS. Further, on 11 January 2013, Japan issued a further communication – this time in response to the submission made by the Republic of Korea – reiterating the same objections it had raised against China’s submission.
The thirty-second session of the CLCS is due to take place in New York between 15 July and 30 August 2013. In view of Japan’s recent communications, however, it appears unlikely that the CLCS will act upon the recent submissions of China and the Republic of Korea. Even if the CLCS were to consider these submissions, UNCLOS stipulates that the actions of the CLCS must not “prejudice matters relating to the delimitation of boundaries between States with opposite or adjacent coasts.” Thus, CLCS’ mandate would be limited to making recommendations on matters which did not prejudice the legal positions of the disputant States, such as the legal significance of the Okinawa Trough.
In any event, the submissions made by China and the Republic of Korea are undoubtedly of political significance, perhaps constituting the basis of future discussions or negotiations between the States concerned. Indeed, it has been posited that the timing and coordinated nature of the submissions put forward may not be coincidental, but may represent a “joint effort” by China and the Republic of Korea to put pressure on Japan. It remains to be seen how the CLCS will respond.