Japan’s practice towards South Korea
As pointed out above, Japan considers that natural prolongation has no role to play in the delimitation of maritime boundaries where the distance between two States is less than 400 nm and that the Okinawa Trough cannot be interpreted as having any particular legal implications on maritime delimitation. Korea, similarly to China, claims the greater part of the East China Sea shelf as its natural prolongation. Amid the 1973 global oil crisis, Japan, South Korea and Taiwan agreed in principle to establish a trilateral joint development zone in the area bounded by their respective claims with a view to jointly carrying out petroleum exploration and exploitation operations in the designated zone and share any benefits deriving therefrom. Taiwan withdrew from this trilateral attempt
Figure 4.5 Australia-Timor-Leste maritime boundaries.
Source: Timor Sea Conciliation Commission Report and Recommendations (PCA 2017).
in view of China’s strong opposition. Negotiations continued on a bilateral basis between Japan and South Korea and resulted, in 1974, in the conclusion
1
Vasco Becker-Weinberg, Joint Development of Hydrocarbon Deposits in the Law of the Sea (Springer 2014) 97; Douglas Johnston and Philip M Saunders (eds) Ocean Boundary Making: Regional Issues and Developments (Croom Helm 1988) 97.
of the ‘Agreement Concerning Joint Development of the Southern Part of the Continental Shelf Adjacent to the Two Countries’.[1]
Interestingly, the limits of the Japan/Korea joint development zone present the overlap of 24,092 square nautical miles bounded by the outer edge of South Korea’s extended continental shelf situated at the axis of the Okinawa Trough and Japan’s 200 nm continental shelf. Indeed, the fixed points of Korea’s outer continental shelf limits beyond 200 nm (shown in South Korea’s 2009 submission to the Commission on the Limits of the Continental Shelf as points KOR-1 to KOR-4) are virtually identical to the fixed points established in the Japan/Korea 1974 Agreement (Figures 4.6 and 4.7)] As a result, the location of the joint development zone is more favourable to South Korea given that a large portion of the joint development zone falls on the Japanese side of the virtual
Figure 4.6 Japan-South Korea maritime boundary and joint development zone.
Source: International Boundaries Research Unit, Durham University, Maritime Briefing Vol 2(5) (1999).
Figure 4.7 South Korea’s continental shelf claim in the East China Sea.
Source: Republic of Korea, Preliminary Information Regarding the Outer Limits of the Continental Shelf (2009).
median line between Japan and South Korea.[2] Thus, while the Japan/Korea 1974 Agreement is not based solely on the principle of natural prolongation, in fact this principle is rejected by Japan, it is nonetheless safe to say that Korea’s claim based on the natural prolongation of its continental margin to the axis of the Okinawa Trough was duly respected in the agreement.
Turning now to the potential implications of the Japan/Korea 1974 Agreement on the future maritime boundary delimitation between China and Japan. Some authors suggest that the establishment of the Japan/Korea joint development zone has strengthened Chinese claims in the area, a fact which largely explains why China has been pushing for a similar solution in its maritime boundary dispute with Japan.[3] Indeed, it may be said that where a particular State votes in favour of a solution that explicitly or implicitly acknowledges a particular fact (e.g. the peculiar geomorphological configuration of the area under dispute), it would be hardly feasible to deny the existence of the exact same fact vis-a-vis a third State. This observation becomes clearer when one considers that the basis of South Korea’s claim is one and the same with China’s. Korea’s preliminary submission to the CLCL provides
The outer limits of the continental shelf in the East China Sea beyond 200 M from the baselines from which the breadth of the territorial sea of Korea is measured are located in the Okinawa Trough, where the seabed and subsoil of the East China Sea comprises a continuous continental landmass extending from Korea’s coast to the limits specified in the Convention.
The southern-most fixed points of the Korean outer continental shelf margin, which are also the limits of the Japan/Korea joint development zone, almost coincide with the northern-most fixed points of China’s extended continental shelf claim.
Notwithstanding the foregoing, it is important to note that the Japan/Korea 1974 Agreement was negotiated and concluded exclusively on the basis of the legal and physical regime of the continental shelf because the EEZ concept, which recognises seabed jurisdiction based on the distance criterion alone, was still in its infancy at the time. Indeed, the notion of the EEZ is a relatively recent one, insofar as it only found legal expression in international law through UNCLOS which only came into force in 1994. It is noteworthy that South Korea and Japan only promulgated EEZ regulations in 1996; that is, more than 20 years after the institution of their joint development zone in 1974.16'’ Directly related to this legal consideration is the fact that, following the introduction of the EEZ, international maritime delimitation law, as developed in State practice and jurisprudence, has shown a remarkable preference for distance-based criteria, to the exclusion of geological and geomorphological factors. As noted above, it was not until the aftermath of the Libya/Malta case in 1985 that the concept of natural prolongation and other geological or geomorphological considerations were effectively abandoned as relevant circumstances in maritime boundary delimitation. Moreover, the Japan/Korea 1974 Agreement is limited to the geographical area which is the subject of the agreement and does not give rise to any rights, either directly or indirectly, to third parties, such as China, in the remaining parts of the East China Sea. Importantly, the 1974 Agreement provides that its terms are without prejudice to the positions of Japan and South Korea with respect to the delimitation of the continental shelf.[4]
So far, the analysis in this chapter has focussed on the potential relevance of geology and geomorphology to the delimitation of the maritime boundaries between China and Japan in the East China Sea. The following section considers the second important issue in this dispute, namely, the legal status of the Senkaku/Diaoyu islands under Article 121 of UNCLOS and their possible effect in the maritime boundary delimitation between China and Japan in the East China Sea.
- [1] Agreement Concerning Joint Development of the Southern Part of the Continental Shelf Adjacent to the Two Countries (Japan/Republic of Korea) (adopted 30 January 1974, entered into force 22 June 1978) (1981) 1225 United Nations Treaty Series 114 (Japan/Korea 1974 Agreement). 2 Republic of Korea, Preliminary Information Regarding the Outer Limits of the Continental Shelf (2009)
; see also, Republic of Korea, Partial Submission to the Commission on the Limits of the Continental Shelf Pursuant to Article 76 Paragraph 8 of the United Nations Convention on the Law of the Sea (2012) . - [2] Sun Pyo Kim, Maritime Delimitation and Interim Arrangements in North East Asia (Martinus Nijhoff 2004) 303-4. 2 Douglas Johnston and Philip M Saunders (eds) Ocean Boundary Making: Regional Issues and Developments (Croom Helm 1988) 97, 98.
- [3] Ibid. 2 Seokwoo Lee and Young Kil Park, ‘Maritime Delimitation and Joint Resource Development in the East China Sea’ (UC Berkeley-Korean Institute of Ocean Science and Technology Conference, May 2012) 11-3
. 3 Republic of Korea, Preliminary Information Regarding the Outer Limits of the Continental Shelf (2009) . 4 People’s Republic of China, Submission Concerning the Outer Limits of the Continental Shelf Beyond 200 Nautical Miles From The Baselines (2012) 7-8 . 5 Art II, Japan/Korea 1974 Agreement, ‘The Joint Development Zone shall be the area of the continental shelf bounded by straight lines connecting the following points...*; see also Art XXVII of the Japan/Korea 1974 Agreement which states that the Agreement shall not affect activities in the superjacent waters. - [4] 1996 Exclusive Economic Zone and Continental Shelf Law (JPN)
