全球外大陆架划界进展与形势分析

方银霞 尹 洁 唐 勇 李金蓉

全球外大陆架划界进展与形势分析

方银霞*尹 洁**唐 勇***李金蓉****

自2001年俄罗斯率先提交划定其200海里以外大陆架外部界限的划界案以来已经15年，截至2016年6月30日，大陆架界限委员会收到的划界案总数达81个，完成审议并通过委员会建议的划界案有24个。本文系统介绍了全球外大陆架划界案提交情况、委员会对划界案的处理模式以及审议时重点关注的问题等，并从科学和法律两个角度分析了当前外大陆架划界实践的特点与未来发展趋势。因此，本文建议，我们应加大相关科学技术和法理问题研究，及时总结大陆架制度理论与实践的最新发展，以便为我国今后外大陆架划界和积极应对侵害我国海洋权益的他国划界主张提供参考和借鉴。

200海里以外大陆架 划界案 大陆架界限委员会 委员会建议

一、引 言

根据《联合国海洋法公约》（以下简称“《公约》”）第76条规定，沿海国的大陆架包括其领海以外陆地领土的全部自然延伸，扩展到大陆边外缘的海底区域的海床和底土，如果从领海基线量起到大陆边的外缘的距离不到200海里，则扩展到200海里；如果超过其领海基线200海里，则可以主张200海里以外的大陆架。①国家海洋局海洋发展战略研究所编：《联合国海洋法公约（汉英）》，北京：海洋出版社1996年版。根据《公约》上述规定，沿海国可根据其大陆边缘的地貌形态和地质条件，将大陆架外部界限最远划到领海基线350海里或2500米等深线外100海里。《公约》附件二第4条还规定，拟按照第76条划定其200海里以外大陆架外部界限的沿海国，应将这种界限的详情连同支持这种界限的科学和技术资料（以下简称“划界案”），尽早提交至大陆架界限委员会（以下简称“委员会”）。

为了执行《公约》第76条，委员会于1997年3月正式成立。根据《公约》规定，委员会除了为沿海国提供大陆架外部界限划定的科学和技术咨询意见外，其主要职能是审议沿海国提交的关于200海里以外大陆架外部界限的划界案并提出建议，沿海国根据委员会建议确定的大陆架外部界限才是具有约束力的最后界限。

委员会于1997年第2届会议上通过了《委员会的工作方式》，②CLCS/L.3文件。2001年第9届会议上通过了《委员会小组委员会内部程序》，③CLCS/L.12文件。2004年第13届会议上通过了《大陆架界限委员会议事规则》（以下简称“《议事规则》”），后者取代了上述2份文件。由于委员会工作是项全新的工作，因此随着外大陆架划界实践的不断发展，《议事规则》也在不断补充和完善中，2008年4月委员会第21届会议通过了修订版《议事规则》，基本明确了委员会的工作方式和流程。④CLCS/40/Rev.1文件。1999年5月13日委员会第5届会议还通过了《大陆架界限委员会科学和技术准则》（以下简称“《科学和技术准则》”）及其附件等一系列重要技术文件。⑤CLCS/11文件。《议事规则》和《科学和技术准则》的通过表明委员会已经做好了接受沿海国划界案的准备工作。考虑到只有在委员会通过《科学和技术准则》之后，各沿海国才能依照《科学和技术准则》要求编写划界案，2001年《公约》缔约国第11次会议决定，对于《公约》在1999年5月13日以前开始对其生效的缔约国，《公约》附件二第4条规定的向委员会提交划界案的10年期限从《科学和技术准则》通过的1999年5月13日开始起算，⑥SPLOS/72号文件。也就是说，这些沿海国划界案提交的截止日期统一为2009年5月13日。

二、外大陆架划界案提交概况

2001年12月20日，俄罗斯率先向委员会提交了划界案，这是委员会成立以来收到的第1个划界案。自俄罗斯划界案提交以来的近15年里（截至2016年6月30日）划界案总数已达81个（含俄罗斯、巴西和巴巴多斯的4个修订划界案）（图1）。⑦At http://www.un.org/depts/los/clcs_new/commission_submissions.htm, 18 October 2016.从提交时间来看，2009年5月13日截止日前共有50个划界案，占62%，截止日之后提交了31个，占38%。从划界案形式来看，81个划界案中，修订划界案4个，联合划界案7个，⑧法国、爱尔兰、西班牙、英国有关凯尔特海和比斯开湾区的联合划界案，毛里求斯和塞舌尔关于马斯克林海台的联合划界案，密克罗尼西亚、巴布亚新几内亚和所罗门群岛关于翁通瓜哇海台的联合划界案，马来西亚和越南关于南海南部的联合划界案，法国和南非关于克罗泽群岛和爱德华王子群岛的联合划界案，图瓦卢、法国、新西兰（托克劳）关于罗比海脊的联合划界案，佛得角、冈比亚、几内亚比绍、几内亚、毛里塔尼亚、塞内加尔和塞拉利昂西非七国联合划界案。部分划界案多达48个，另有5个划界案在委员会审议之前又提交了补充材料。⑨斐济划界案，库克群岛关于马尼基希海台划界案，法国和南非关于克洛泽群岛和爱德华王子群岛的联合划界案，南非大陆划界案，密克罗尼西亚、巴布亚新几内亚、所罗门群岛关于翁通爪哇海台的联合划界案。从划界案的提交国来看，81个划界案共涉及77个国家，部分国家以不同形式提交了多个划界案，其中，最多的是法国，共提交了7个（含3个联合划界案），英国提交了4个（含1个联合划界案），丹麦提交了4个，爱尔兰和西班牙均提交了3个（各含1个联合划界案），挪威、墨西哥、汤加都提交了2个，另有新西兰、毛里求斯、南非、密克罗尼西亚、越南、塞舌尔等国也都提交了2个（各含1个联合划界案）。

除重复的4个修订案外，77个划界案中有68个划定的外大陆架呈圈闭的多边形区，但也有9个划界案只确定了大陆架外部界限，并未形成圈闭区块，如苏里南划界案、英国关于哈顿—罗科尔区划界案、越南关于中国南海北部划界案、英国有关福克兰岛的划界案、汤加关于克马德克海脊东部区划界案、中国东海部分海域划界案、韩国划界案、尼加拉瓜划界案、法国关于圣皮埃尔—密克隆岛划界案。由于未形成圈闭多边形，这9个划界案的外大陆架面积无法准确计算，剩余68个划界案所申请的外大陆架总面积约3000多万平方千米。

图1 全球外大陆架划界形势图（据委员会官网发布的划界案数据编绘）（绿色为专属经济区，橙色为沿海国划界案所主张的外大陆架）

考虑到缔约国，特别是包括小岛屿发展中国家在内的发展中国家，在履行《公约》附件二第4条规定的10年期限时可能会遇到的问题，2008年缔约国第18次会议决定，可通过提交200海里以外大陆架外部界限的初步信息以及关于划界案编写情况和预计提交日期的说明（以下简称“初步信息”）来满足《公约》附件二第4条关于10年期限的规定。⑩SPLOS/183号文件。

到2016年6月30日，共有44个国家提交了47份初步信息，①At http://www.un.org/depts/los/clcs_new/commission_preliminary.htm, 18 October 2016.其中在2009年5月13日截止日前共有39个国家提交了42份初步信息，此后，不受统一截止日期限制的赤道几内亚、科摩罗、瓦努阿图、尼加拉瓜、加拿大和摩洛哥6国又先后提交了初步信息。提交的47份初步信息中有3份为联合初步信息；②贝宁和多哥关于几内亚湾区的联合初步信息，斐济和所罗门群岛关于夏洛特暗滩区的联合初步信息，斐济、所罗门群岛和瓦努阿图关于北斐济海盆区的联合初步信息。提交初步信息的44个国家中发达国家有4个，分别是法国、西班牙、新西兰和加拿大，其余40个均为发展中国家；法国、毛里求斯、多哥和所罗门群岛4国都提交了2份初步信息。

对比初步信息和划界案提交情况可以发现，44个提交初步信息的国家中已经有25个国家（占57%）正式向委员会提交了18个划界案，其中含佛得角、冈比亚、几内亚比绍、几内亚、毛里塔尼亚、塞内加尔和塞拉利昂的西非七国联合划界案。

三、委员会对划界案的处理模式

委员会是按照各国提交划界案的先后顺序进行审议的。截至2016年6月30日，委员会已完成24个划界案（含俄罗斯和巴巴多斯2个修订案）的审议，并在联合国网站发布了委员会建议摘要。③At http://www.un.org/depts/los/clcs_new/commission_submissions.htm, 18 October 2016.此外，委员会全会正在审议的建议草案有2个，小组委员会正在审议的划界案有10个（包括新提交的俄罗斯关于北冰洋的修订划界案），另有7个划界案被推迟审议。迄今，不审议的情况主要有两种，第一种是涉及南极陆地领土的划界案，如澳大利亚、阿根廷、挪威划界案均涉及到《南极条约》关于冻结南纬60°以南领土所有权主张的规定，委员会认为其无权处理与《南极条约》相关的问题而不予审议。第二种情况是如果两个国家提出的划界案涉及同一区域，并存在领土主权或海域划界争端，委员会则对此不予审议，如阿根廷和英国划界案所涉及的马尔维纳斯群岛（英称福克兰群岛），因划界案涉及马尔维纳斯群岛的主权归属问题，委员会决定不审议。从委员会审议划界案情况的分析可以看出，委员会对划界案的处理模式通常有以下3种。④李金蓉、罗婷婷、万芳芳：《200海里外大陆架划界案审议进程及发展趋势研究》，载于《国际论坛》2014年第3期，第37～42页。

（1）全部审议：如果划界案所涉及的区域不存在陆地领土和海域划界争端，即委员会未收到有关国对此划界案提出引用委员会《议事规则》附件一第5(a)条款的反应照会，委员会将建立小组委员会负责审议沿海国所拟划定的大陆架外部界限是否具有充分的依据，然后以建议的方式对沿海国提交的外大陆架主张作出认可、部分认可或否定的决定。如已经完成审议并通过委员会建议的俄罗斯划界案及其鄂霍次克海修订案、巴西划界案、爱尔兰关于波丘潘深海平原的划界案、新西兰划界案、法国—爱尔兰—英国—西班牙联合划界案、挪威关于东北大西洋和北冰洋区的划界案、墨西哥关于墨西哥湾西部多边形区划界案、巴巴多斯划界案及其修订案、英国关于阿森松岛划界案、印度尼西亚关于苏门达腊岛西北区划界案、毛里求斯和塞舌尔联合划界案、苏里南划界案、法国关于安的列斯群岛和凯尔盖朗岛划界案、菲律宾关于贝汉姆隆起划界案、加纳划界案、丹麦关于法罗群岛划界案和巴基斯坦划界案。

（2）推迟审议：在有些划界案中，尽管相关国家有引用《议事规则》附件一第5(a)提交的反应照会，但由于该划界案仍在排队中，考虑到有关国家正在或即将协商解决争端，委员会决定暂时搁置划界案，待排队轮到时再做考虑；如果争端问题仍未解决则继续等候，直至相关国家都不反对。如缅甸划界案因孟加拉的反对推迟审议，也门关于索科特拉岛东南区划界案因索马里的反对推迟审议，斐济划界案因瓦努阿图的反对推迟审议，英国和爱尔兰关于哈顿—罗科尔区两个划界案均因冰岛和丹麦的反对推迟审议，马来西亚—越南联合划界案也因为中国和菲律宾提交了反对照会而推迟审议，肯尼亚划界案则因索马里的反对而推迟审议。

（3）部分审议：如上所述，如果沿海国所提交的划界案中的部分区域涉及南极陆地领土，或者涉及陆地领土或海域划界争端，委员会按照具体情况采取不审议或推迟审议，或只对其中不涉及南极、陆地领土或海域划界争议部分进行审议并给出建议。如对澳大利亚划界案中涉及南极陆地领土部分不审议，只审议了澳大利亚划界案的阿尔戈区、澳大利亚大海湾区、凯尔盖朗海台区、豪勋爵海隆区、麦夸里海岭区、博物学家海台区、三王海脊区、沃勒比和埃克斯茅斯海台区等9个区块。对阿根廷划界案中涉及南极陆地领土部分和涉及领土争端的马尔维纳斯群岛部分均不审议，只审议了阿根廷被动陆缘北部区和复合型陆缘西部区。另外，暂不审议法国关于法属圭亚那和新喀里多尼亚划界案中涉及新喀里多尼亚东南区的部分，只审议了法属圭亚那部分和新喀里多尼亚西南区。对日本划界案中涉及冲之鸟礁的部分也暂不审议，只审议了南硫磺岛区、南鸟岛区、茂木洋脊区、小笠原海台区、冲大东洋脊南部区和四国海盆区。⑤方银霞、唐勇、付洁：《日本划界案大陆架界限委员会建议摘要解读》,载于《中国海洋法学评论》2013年第2期，第96～109页。

四、委员会审议划界案重点关注的问题

根据委员会《议事规则》的相关规定，划界案的委员会建议全文是不公开的，所以我们很难全面了解委员会对划界案的审议情况，但是划界案的建议摘要委员会会妥为公布在联合国网站上，我们藉此可大致了解委员会对划界案的审议情况。从公布的委员会建议摘要来看，委员会对划界案的审议主要按委员会是否有权审议、划界海域的区域地质地理概况、沿海国陆块的自然延伸情况、大陆坡脚的确定、大陆边外缘的确定、大陆架外部界限的确定等内容进行。从建立小组委员会开始，在具体审议划界案的过程中，小组委员会审议重点主要在于陆坡基部区和大陆坡脚是否合理、1%沉积物厚度点是否可靠、2500米等深线外延100海里限制线是否适用、200海里线上的点是否合理等问题。

（一）陆坡基部区及大陆坡脚点是否合理

委员会认为大陆坡脚是一项重要的地形特征，《公约》规定的扩展大陆架的两条公式线均是基于大陆坡脚来确定，因此它是扩展大陆架的重要基础，也是委员会审议的一个重要参数。根据《科学和技术准则》规定，大陆坡脚的确定主要有两种方法，一种是根据大陆边缘的地形地貌形态特征，在陆坡基部区选取坡度变化最大之点，另一种方法是利用相反证据，在利用坡度变化最大之点的地貌证据无法可靠地确定大陆坡脚位置时，可以基于利用地质和地球物理等证据得到的洋陆过渡带来确定大陆坡脚。从目前已审议完成的划界案来看，大陆坡脚的确定基本都采用第一种方法，即在陆坡基部区选择坡度变化最大之点作为大陆坡脚。

在英国关于阿森松岛划界案的审议过程中，委员会对英国提出的陆坡基部区以及确定的大陆坡脚位置提出质疑，双方经多次沟通，始终未达成一致意见。英国把大西洋洋中脊扩张轴的拉张裂谷以及与裂谷区有关的深海盆地都看作是阿森松岛的陆坡。委员会认为作为深海底一部分的大洋扩张构造，只有当这些离散的海底构造隆起形成岛屿时才能成为该岛屿陆坡的一部分，而阿森松岛明显不属于这种情况，阿森松岛在地形地貌上与这些离散分布的海底隆起并不连续（图2）。委员会建议指出，阿森松岛和中大西洋洋中脊轴部之间的起伏海底属于正常洋壳的一部分，而非阿森松岛的陆坡区，因此，英国在该区选定的大陆坡脚点均未得到委员会的认可。⑥At http://www.un.org/Depts/los/clcs_new/submissions_fles/gbr08/gbr_asc_isl_rec_summ. pdf, 18 October 2016.

图2 委员会建议的阿森松岛大陆坡脚确定示意图⑦

（二）1%沉积物厚度点是否可靠

沉积物厚度规则是确定扩展大陆架的权利和划定其外部界限的两个同等有效的公式线之一，委员会对此审议也非常严格。沉积物厚度公式线的确定涉及沉积基底的确定、沉积物厚度的计算和沉积物分布的不连续性等技术问题。沉积物厚度可以通过直接取样和间接勘测方法来确定，因为用钻探等直接取样方法费用昂贵，目前所提交的划界案均是通过地震数据间接计算而来，这就涉及到沉积层的识别、速度谱分析、时深转换等数据的可靠性问题，一般间接计算出的沉积厚度会有10%的误差。比如，委员会在巴巴多斯划界案审议中，对其中一个沉积物厚度点GP12的确定存有异议，委员会认为巴巴多斯确定的厚度点涉及到大间距的内插计算，要求提供其他佐证数据。为此，巴巴多斯提供了新的声纳浮标数据来证实其速度模型，并利用地震测线对GP12点做了重新确定后才获得委员会通过。⑧At http://www.un.org/Depts/los/clcs_new/submissions_fles/brb_10rev2011/brb_10rev2011 _summary_recommendations.pdf, 18 October 2016.

（三）2500米等深线外延100海里限制线是否适用

《公约》第76条提到三种法律意义上的脊，即深洋洋脊、海底洋脊和海底高地，它们所具有的外大陆架权利不同，其中，深洋洋脊没有外大陆架，海底洋脊的大陆架外部界限最远不能超过350海里，而作为大陆边自然组成部分的海底高地，最远可扩展至350海里或2500米等深线外推100海里。《公约》第76条虽规定了三类“脊”的大陆架权利，但对三类“脊”却未给出准确的定义或较明确的判别方法。由于《公约》对脊规定的不确定性，导致《科学和技术准则》也没能提供最终的解决方案，一些学者对此也进行过探讨，如委员会前委员西蒙兹等在论述洋脊条款时，将脊分为离散构造背景和汇聚构造背景下形成的两大类脊，认为脊的分类需考虑脊的成因、所处构造位置等地质因素。⑨Philip A. Symonds, Mike F. Coffin, George Taft and Hideo Kagami, Ridge Issues, in Peter J. Cook and Chris M. Carleton eds., Continental Shelf Limits: The Scientific and Legal Interface, New York: Oxford University Press, 2000, pp. 285～307.但同为委员会前委员的布瑞克等对脊的分类，则没有考虑脊的地质形成过程，而是更多的考虑脊与大陆边的位置关系。⑩Harald Brekke and Philip A. Symonds, The Ridge Provisions of Article 76 of the UN Convention on the Law of the Sea, in Myron H. Nordquist, John Norton Moore and Tomas H. Heidar eds., Legal and Scientific Aspects of Continental Shelf Limits, Leiden/Boston: Martinus Nijhof f Publishers, 2004, pp. 169～199.从善意解释《公约》的角度出发，笔者认为只有与沿海国陆地及其水下自然延伸部分在地形上连续的，在地质属性上是一致的脊才为海底高地；地形上不连续的脊为深洋洋脊；而介于两者之间，在地形上是连续的但地质属性上不一致的脊则为海底洋脊。①Wang Weiguo, Geological Structures of Ridges with Relation to the Definition of Three Types of Seafoor Highs Stipulated in Article 76, Acta Oceanologica Sinica, Vol. 30, No. 5, 2011, pp. 125～137.关于脊的界定，目前仍没有较明确的判别原则与方法，委员会在对待具体的划界案时，对脊属性的认识也不完全一致。

比如，委员会在审议澳大利亚划界案时，对威廉姆斯海岭、乔伊海隆是否为《公约》第76条所定义的海底高地提出质疑，委员会认为澳大利亚提交的数据只给出了关于威廉姆斯海岭和乔伊海隆性质和地质起源的间接证据，不足以清晰解释它们的地质成因，不能认定为是海底高地，也不同意澳大利亚根据2500米等深线外推100海里限制线确定的外部定点。②At http://www.un.org/Depts/los/clcs_new/submissions_fles/aus04/Aus_Recommendations_ FINAL.pdf, 18 October 2016.由此可见，委员会对三类脊的判定不仅仅只根据地形连续性，还充分考虑到地质属性上的一致性，这也完全符合《公约》规定不同脊享有不同大陆架权利的初衷。

（四）200海里线上的点是否合理

《公约》第76条第7款规定，沿海国的大陆架如从测算领海宽度的基线量起超过200海里，应连接以经纬度坐标标出的各定点划出长度各不超过60海里的若干直线，划定其大陆架的外部界限。因此，澳大利亚划界案在其主张的各个区块，为了达到利益最大化，均采用长度不超过60海里的线段连接公式线确定的点和200海里线上的任何定点来确定外部界限。然而，委员会认为，这样确定的外大陆架范围超出了《公约》规定的范围，大陆架外部界限最后定点的确定应根据公式线与200海里线的交点来确定。因此，委员会不同意澳大利亚划界案所有区块所提交的位于200海里线上的点的确定方法。同理，委员会也不同意澳大利亚划界案在麦夸里海岭区和三王海岭区用不超过60海里的直线来确定位于澳大利亚—新西兰海洋界线上的各点。③At http://www.un.org/Depts/los/clcs_new/submissions_fles/aus04/Aus_Recommendations_ FINAL.pdf, 18 October 2016.

（五）350海里线外的点是否合理

这种情况主要见于联合划界案中，在提交的第一个法国—英国—爱尔兰—西班牙四国联合划界案审议过程中，委员会发现尽管外部界限点FP 30位于西班牙350海里线之内，但却位于其他三国350海里线之外。而且委员会认为FP 30是基于爱尔兰而非西班牙的大陆边缘扩张延伸得到的，应该受爱尔兰350海里线的限制，因此，该点应落在爱尔兰350海里限制线内/上而非线外，最终四国划界案据此建议做了修改才获得委员会的审议通过。④At http://www.un.org/Depts/los/clcs_new/submissions_fles/frgbires06/fsu_clcs_recommen dations_summary2009.pdf, 18 October 2016.

五、外大陆架划界实践的特点与发展趋势

外大陆架蕴藏着丰富的自然资源。同时《公约》第77条第1款写明，“沿海国为勘探大陆架和开发其自然资源的目的，对大陆架行使主权权利。”可见，200海里以外大陆架外部界限的划定，不仅关系到沿海国的主权权利问题，也与各国的经济利益直接相连。由于外大陆架丰富的自然资源及提交划界申请所产生的宣示主权效应，各国对于外大陆架申请这一“蓝色圈地运动”越来越重视，投入力度也越来越大。特别是自2001年俄罗斯首次提交其划界案以来的15年，沿海国关于外大陆架划界的国家实践和委员会对划界案的审议工作模式都在不断发展。从沿海国实践来看，各沿海国划界案的提交一开始主要还是为截止期限所迫，但现在越来越多的国家以积极主动的态度，通过外大陆架划界案的提交，全方位多层次地维护其海洋权益，凸显和加剧了全球海洋划界争端。从委员会工作实践来看，委员会对划界案的审议程序、审议原则等均逐渐发展为固定模式，并反过来或多或少地影响着沿海国外大陆架划界的实践。总体来看，全球外大陆架划界实践具有以下特点。

（一）划界主张存在大量重叠

从目前提交的77个划界案来看，外大陆架主张重叠严重，其中有47个国家的主张区或多或少存在重叠（表1），且有个别情况非常严重，比如孟加拉、印度、缅甸、斯里兰卡4国在孟加拉湾主张的外大陆架几乎完全重叠在一起。此外，英国关于马尔维纳斯群岛的大陆架主张也几乎与阿根廷主张完全重叠；英国、爱尔兰、冰岛、丹麦四国在北大西洋哈顿—罗科尔海域的大陆架主张存在重叠；中国东海除了中日之间存在以钓鱼岛主权归属为核心的争议外，韩国也在该海域提出外大陆架主张。在南海海域，则是以南沙群岛的主权归属为核心的中国、越南、马来西亚和菲律宾等国之间的争议。实际上，各国外大陆架划界主张重叠源于各海域已经存在的主权争端和划界冲突，外大陆架划界只是将这些矛盾重新显示了出来。有些颇有争议的划界案，委员会肯定不会审议，但是对申请国而言，无论审议与否，通过提交外大陆架划界案都达到了宣示主权的目的。因此，宣示主权也成了沿海国提交外大陆架划界申请的重要原因。

表1 外大陆架划界主张重叠情况统计

18加纳—尼日利亚几内亚湾19肯尼亚—索马里东非大陆边缘20马尔代夫—斯里兰卡北大西洋21孟加拉—缅甸—斯里兰卡—印度孟加拉湾22莫桑比克—南非西南印度洋23葡萄牙—西班牙加那利群岛北部海域24葡萄牙—西非七国加那利群岛南部海域25日本—帕劳菲律宾海26索马里—坦桑尼亚东非大陆边缘27索马里—也门东非大陆边缘28中国—韩国中国东海

（二）部分划界案和联合划界案成为许多国家的选择

由于各国划界主张重叠严重，在实践中，如果有关划界案涉及划界争端或者其他相关海上或陆上争端，利害关系国往往通过递交外交照会发表评论意见的方式表达关切或反对，而此种评论意见可能足以阻止委员会审议存在海上或陆上争议的划界案。但委员会《议事规则》附件一的第3条建议，为暂时回避争端，沿海国可就其一部分的大陆架提出划界案，以避免妨害以后国家间在大陆架任何其他部分划定界限所涉及的问题。该规定促使一些沿海国为回避争议，仅仅就无争议的部分先行提出外大陆架划界申请。目前已提交的77个划界案中，部分划界案就高达46个，占全部划界案的60%。

除了避免争端之外，部分申请的另一个好处是沿海国可以通过集中力量，增加申请获得委员会认可的可能性。外大陆架的划定涉及到复杂的法律、科学和技术问题。由于在某一问题上经常存在科学认识上的差异，因此原则上任何申请都不可避免地存在一定程度的不确定性。而如果申请国的主张与审议时小组委员会的意见有所差别，除非该国提供充分的证据，否则很难得到委员会的认可。在这种情况下，一国先对有充分证据的海域提出部分申请无疑是明智的，尤其对于面临科学、技术和财政等多方面问题的发展中国家特别适用。

（三）南北极大陆架划界引起普遍关注

对南极正式提出领土要求的国家有7个，即澳大利亚、新西兰、阿根廷、智利、法国、英国、挪威，主要针对的是南纬60°到南极点的扇形区域。目前，对南极领土提出主张的七国中，除智利仅提交关于大陆架外部界限的初步信息外，澳大利亚、新西兰、挪威、法国、英国和阿根廷均已向委员会正式提交了划界案或部分划界案。特别是，澳大利亚、挪威、阿根廷三国在其划界案中都对南极洲领土主权及南极洲大陆架提出明确主张，澳大利亚、阿根廷和英国还有部分地区的大陆架主张延伸至南纬60°以南，即延伸至南极条约体系的适用范围内。众所周知，南纬60°以南的南极地区，是南极条约体系的适用范围。《公约》确立了12海里的领海和200海里的专属经济区，并建立和发展了大陆架及国际海底区域制度。但这些制度如生搬硬套至南极地区，无疑会对南极条约体系中既存的法律规定构成挑战。

北极地区的法律制度和南极不同，并没有一个完整的条约体系。现行有关北极地区的国际法规只局限于解决某一具体问题，尚无将北极地区或北冰洋作为一个整体加以管理的法律。北冰洋周边国家主要有俄罗斯、加拿大、美国、丹麦、挪威、芬兰、瑞典和冰岛8个国家，但真正意义上的北冰洋沿海国则只有俄罗斯、加拿大、美国、丹麦、挪威等组成A5集团的5个国家。北冰洋沿海国家中除美国以外其他均为《公约》缔约国。俄罗斯、挪威、丹麦均提交了涉及北冰洋的划界案（图3）。其中，俄罗斯划界案在2002年被委员会认为科学证据不足未获通过，但近10多年来俄在北冰洋开展了大规模科学调查，并基于大量地质和地球物理证据于2015年8月提交了其修订案，其主张的外大陆架面积不减反增。挪威划界案涉及北冰洋大陆架的是斯瓦尔巴群岛，该划界案已获委员会审议通过。丹麦划界案分别涉及格陵兰东北部和北部，特别是2014年12月提交的格陵兰北部划界案，其主张外大陆架向北越过北极极点延伸至俄罗斯的200海里线。此外，加拿大一直宣称已完成北冰洋划界案编制，将于近期择机提交。美国尽管尚未批准加入《公约》，但也绝对不会放弃扩展其大陆架的权利。因此，随着A5集团各国划界案的提交，北冰洋外大陆架划界将日趋白热化。

图3 北冰洋外大陆架划界形势图

（四）洋脊规则成为外大陆架划界中最复杂问题

脊状的海底高地地形/地貌在深海洋盆及大陆边缘普遍存在，其面积约占海洋总面积的33%以上。上文已经提及，《公约》对大陆架的定义，考虑了各种海脊及其与陆架区的关系，提出了深洋洋脊、海底洋脊和海底高地等3类海脊，并对这3类海脊的大陆架权利做了规定。但由于海脊的多样性和地质特征的复杂性，加上《公约》对这3个术语未给出准确的科学定义或较明确的判别方法，导致在实际应用过程中，海脊问题成为外大陆架划界中最复杂的问题，也为沿海国利用海脊规则争取本国利益最大化提供了机会。从所提交的划界案来看，绝大多数沿海国都把成因各异的洋脊、海岭、海隆、海丘、海台等各种各样的海脊当做大陆边自然组成部分的海底高地处理，以便最大限度地扩展本国大陆架，对本应属于国际海底区域的部分提出主张，侵占全人类的共同利益。

尽管目前学界对海脊规则的应用开展了探讨并形成初步共识，但实践中关于脊属性的界定，还是十分复杂，委员会在审议具体划界案时，对涉及的脊一般采取逐案审议的方法，对各类脊属性的认定所采用的原则也不完全一致。从委员会审议结果来看，对于大陆分裂形成的微大陆，由于其古老陆壳的存在，不管其规模大小，一般都将其认定为海底高地；对于海底扩张形成的洋中脊，由于其百分百的洋壳属性，一般都将其认定为深洋洋脊。但对于成因多源的各类复合型脊就复杂得多，特别是沿汇聚型大陆边缘形成的脊和增生脊，目前争议还比较大。此外，对于各类脊大陆架权利的认定，委员会还综合考虑了脊的地形地貌特征、地质属性以及地质与地球物理支撑证据。对于地壳性质明显、地质证据充足的脊，首先考虑的是脊的地质属性一致性；但对于地壳组成和成因演化复杂的脊，往往只能选择考虑地形连续性。总体上，委员会能坚持《公约》基本原则，遵循《公约》制定不同洋脊大陆架权利规定的初衷，做到严格把关和公平公正，维护了国际海底区域利益和国际社会的稳定，这定将对未来世界海洋划界格局产生深远的影响。

六、结 语

200海里以外大陆架划界是《公约》大陆架制度下运用科学证据划定沿海国大陆架外部界限的科学与法律交汇的活动。全球大陆边缘地貌形态和地质特征的复杂性，加上沿海国之间的历史及法律关系各异，造就了目前复杂多样的划界案。当前，外大陆架划界是沿海国利用《公约》合法拓展其管辖权的重大机遇。从15年来所提交的划界案来看，大部分沿海国都对《公约》相关规则和条款尽最大努力进行挖掘和演绎，以便最大限度地扩展其大陆架范围。因此，随着外大陆架划界案的提交和审议的深入，新的科学和法律问题层出不穷，尤其是洋脊规则适用等问题。

沿海国的划界实践以及委员会对划界案的审议，都是关于外大陆架划界科学与法律问题的重要实践。沿海国在划界案中采用的基本原则、主要方法、数据资料支撑等，委员会审议秉持的主要原则、审议的关键问题、提出的意见建议和理由等都是今后大陆架划界和划界案审议工作重要的参考和法理依据。因此，我们应加大相关科学技术和法理问题研究，及时总结大陆架制度理论与实践的最新发展，以便为我国今后外大陆架划界和积极应对侵害我国海洋权益的他国划界主张提供参考和借鉴。

I. Introduction

According to Article 76 of the United Nations Convention on the Law of the Sea (UNCLOS), 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 (nm) 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 distance; and a coastal State may claim a continental shelf beyond 200 nm if the natural prolongation of its land territory extends beyond 200 nm from the baselines of its territorial sea.④China Institute for Marine Af f airs, SOA ed., United Nations Convention on the Law of the Sea (Chinese-English), Beijing: China Ocean Press, 1996.In light of the UNCLOS provision above, the continental shelf of a coastal State may, based on the geomorphological and geological conditions of its continental margin, extend to a distance of 350 nm from the baselines from which the breadth of the territorial sea is measured, or a distance of 100 nm from the 2500 metre isobath. Additionally, UNCLOS Annex II, Article 4 provides that, where a coastal State intends to establish, in accordance with Article 76, the outer limits of its continental shelf beyond 200 nm, it shall submit particulars of such limits to the Commission on the Limits of the Continental Shelf (hereinafter “CLCS” or “Commission”) along with supporting scientifc and technical data (hereinafter “Submission”) as soon as possible.

To implement UNCLOS Article 76, the CLCS was formally established in March, 1997. Pursuant to UNCLOS, apart from providing scientifc and technical advice concerning the outer limits of the continental shelf to coastal States, the primary functions of CLCS also include considering submissions made by the coastal States concerning the outer limits of the continental shelf in areas where those limits extend beyond 200 nm and making recommendations. The limits of the shelf established by a coastal State on the basis of these recommendations shall be fnal and binding.

The Rules of Procedure of the Commission on the Limits of the ContinentalShelf, hereinafter referred to as “Rules of Procedure”, was adopted at its thirteenth session, held in 2004. It replaced the Modus Operandi of the Commission②Document CLCS/L.3.adopted at its second session, held in 1997, and the Internal Procedure of the Subcommission of the Commission on the Limits of the Continental Shelf,③Document CLCS/L.12.adopted at its ninth session, held in 2001. Since the Commission deals with things that have never been done before, its Rules of Procedure is being added and amended during the gradual accumulation of practice pertaining to extended continental shelf delineation. The revised Rules of Procedure was adopted at the 21st session of CLCS in April of 2008 and basically defned its modus operandi and rules of procedure.④Document CLCS/40/Rev.1.At its ffth session held on 13 May 1999, the CLCS adopted a series of important scientific documents, including the Scientific and Technical Guidelines of the Commission on the Limits of the Continental Shelf (hereinafter “Scientific and Technical Guidelines”).⑤Document CLCS/11.The adoption of the Rules of Procedure and the Scientifc and Technical Guidelines implies that the CLCS was well prepared to receive submissions from coastal States. Noting that it was only after the adoption by the Commission of its Scientifc and Technical Guidelines that States had before them the basic documents concerning submissions, the eleventh meeting of States Parties of UNCLOS decided that in the case of a State Party for which UNCLOS entered into force before 13 May 1999, the ten-year time period referred to in Article 4 of Annex II to UNCLOS shall be understood to have commenced on 13 May 1999, when the Scientific and Technical Guidelines was adopted.⑥Document SPLOS/72.That is to say, the deadline for submissions from all these coastal States would be 13 May 2009.

II. An Overview of the Filing of Submissions to CLCS

On 20 December 2001, Russia became the frst to forward its submission to the CLCS; it was the frst submission that CLCS received upon its establishment. As of 30 June 2016, the total number of submissions filed had come to 81, including revised submissions made by Russia, Brazil and Barbados (Fig. 1).⑦At http://www.un.org/depts/los/clcs_new/commission_submissions.htm, 18 October 2016.In terms of the fling time, 50 submissions were made before the deadline (13 May2009), accounting for 62% of the total fled submissions, and 31 after the deadline, accounting for 38% of submissions. Of the⑧Joint Submission by France, Ireland, Spain and the United Kingdom of Great Britain and Northern Ireland in the Area of the Celtic Sea and the Bay of Biscay, Joint Submission by the Republic of Mauritius and the Republic of Seychelles in the Region of the Mascarene Plateau, Joint Submission by the Federated States of Micronesia, Papua New Guinea and Solomon Islands concerning the Ontong Java Plateau, Joint Submission by Malaysia and Viet Nam in the Southern Part of the South China Sea, Joint Submission by France and South Africa in the Area of the Crozet Archipelago and the Prince Edward Islands, Joint Submission by Tuvalu, France and New Zealand (Tokelau) in Respect of the Area of the Robbie Ridge, and Joint Submission by Cabo Verde, The Gambia, Guinea, Guinea-Bissau, Mauritania, Senegal and Sierra Leone in Respect of Areas in the Atlantic Ocean Adjacent to the Coast of West Africa.1 submissions, four submissions were revised, seven were jointly fled,848 were partial, and fve were added with supplementary information before being considered by the Commission.⑨Submission by Fiji, Submission by the Cook Islands concerning the Manihiki Plateau, Joint Submission by France and South Africa in the Area of the Crozet Archipelago and the Prince Edward Islands, Submission by South Africa in Respect of the Mainland of the Territory of the Republic of South Africa, and Joint Submission by the Federated States of Micronesia, Papua New Guinea and Solomon Islands concerning the Ontong Java Plateau.In terms of submissions by States, these 81 submissions were made by 77 States, some of which fled more than one submission in dif f erent forms. Specifcally, France made seven submissions (including three joint submissions), the UK fled four (including one joint submission), Demark filed four, Ireland and Spain each filed three (including one joint submission each), and Norway, Mexico and Tonga each fled two; additionally, New Zealand, Mauritius, South Africa, Micronesia, Vietnam and Seychelles each fled two (including one joint submission each).

Excluding the four revised submissions, 68 of the remaining 77 submissions claimed areas of extended continental shelves in polygon, forming encircled areas. However, nine submissions only established the outer limits of continental shelves, without forming any encircled areas, including the Submissions by Suriname, by the United Kingdom of Great Britain and Northern Ireland in Respect of Hatton Rockall Area, by Viet Nam in North Area, by the United Kingdom of Great Britain and Northern Ireland in Respect of the Falkland Islands, and of South Georgia and the South Sandwich Islands, by Tonga in the Eastern Part of the Kermadec Ridge, by China in Part of the East China Sea, by the Republic of Korea, by Nicaragua in the Southwestern Part of the Caribbean Sea, and by France in Respect of Saint-Pierre-et-Miquelon. Without forming any encircled polygons, it is impossible to calculate the areas of the extended continental shelves established by these nine submissions. The area of the extended continental shelves claimed by the remaining68 submissions comes to more than 30,000,000 km2.

Fig. 1 The Global Situation on the Delineation of Extended Continental Shelves (Based on the Data of the Submissions Released on the Of fi cial Website of CLCS)

Recognizing that some coastal States, in particular developing countries, including small island developing States, continue to face particular challenges in submitting information to the Commission in the ten-year time period referred to in Article 4 of Annex II to the UNCLOS, the Eighteenth Meeting of States Parties decided that the time period referred to in Article 4 of Annex II to UNCLOS may be satisfed by submitting to the Secretary-General preliminary information indicative of the outer limits of the continental shelf beyond 200 nm and a description of the status of preparation and intended date of making a submission (hereinafter“preliminary information”).⑩Document SPLOS/183.

Up to 30 June 2016, 44 States have submitted 47 copies of preliminary information.①At http://www.un.org/depts/los/clcs_new/commission_preliminary.htm, 18 October 2016.Specifically, 39 States submitted 42 copies of preliminary information before the provided deadline (13 May 2009). Thereafter, Equatorial Guinea, Comoros, Vanuatu, Nicaragua, Canada and Morocco, which are not subject to the said deadline, submitted their preliminary information. Among the 47 copies ofpreliminary information submitted, three are joint preliminary information.②Preliminary Information Submitted by Benin and Togo, Preliminary Information Submitted by Fiji and Solomon Islands on the Charlotte Bank Region, and Preliminary Information Submitted by Fiji, Solomon Islands and Vanuatu on the North Fiji Basin.Plus, four of the submitting States are developed States, including France, Spain, New Zealand and Canada, and the remaining 40 States are developing States. France, Mauritius, Togo and Solomon Islands each submitted two copies of preliminary information.

A comparison between the fling of preliminary information and submissions to CLCS reveals that, 25 of the 44 States which have submitted their preliminary information, or 57% of these States, have formally presented 18 submissions to the Commission, including the Joint Submission by Cabo Verde, the Gambia, Guinea, Guinea-Bissau, Mauritania, Senegal and Sierra Leone in Respect of Areas in the Atlantic Ocean Adjacent to the Coast of West Africa.

III. Modes that the CLCS Adopted to Treat Submissions

The CLCS considers submissions in the order filed. By 30 June 2016, the Commission had completed the consideration of 24 submissions, including two revised submissions by Russia and Barbados, and published its summaries of recommendations on the website of the United States.③At http://www.un.org/depts/los/clcs_new/commission_submissions.htm, 18 October 2016.Additionally, two draft recommendations are being reviewed by the Commission; ten submissions, including the newly-fled Partial Revised Submission by Russian Federation in Respect of the Arctic Ocean, are being considered by the subcommission; and the consideration of another seven submissions have been deferred. To date, the Commission has decided not to consider submissions under two circumstances. First, in cases where a submission concerns territorial claims in the Antarctic, the Commission refuses to consider the submission. For example, the Commission refused to consider the Submissions by Australia, by Argentina, and by Norway because they were pertinent to the provisions, as contained in the Antarctic Treaty, banning ownership claims to the area south of 60º South Latitude, and the Commission is not empowered to deal with matters pertaining to the Antarctic Treaty. Second, in cases where the submissions made by two States concern the same area or in cases where there is a land or maritime dispute, the Commission refuses to consider the submission. Examples of such case are the Submissions by Argentina and by theUK. Since these submissions involve the sovereignty issue of the Malvinas Islands (also known as “Falkland Islands” in Britain), the Commission decided not to consider them. These results of consideration indicate that the Commission often adopts the following three modes to treat submissions:④Li Jinrong, Luo Tingting and Wan Fangfang, A Study of the Review Process and Development Trend about the Delineation of the Continental Shelf beyond 200 Nautical Miles, International Forum, No. 3, 2014, pp. 37～42. (in Chinese)

(1) To consider a submission in its complete form. If the area claimed by a submission does not involve land or maritime delimitation disputes, that is to say, if the Commission fails to receive any note verbale in response to the submission, by invoking Article 5(a) of Annex I to the Rules of Procedure, the Commission will establish a subcommission to consider whether the outer limits of continental shelves proposed by a coastal State is well grounded. Then it will decide to approve, partly approve or deny, in the form of recommendations, the claims to extended continental shelves made by the coastal State. Examples of this case include: the Submission by Russian Federation and its Partial Revised Submission in Respect of the Okhotsk Sea, the Submission by Barbados and its Revised Submission, the Submissions by Brazil, by Ireland in Respect of Porcupine Abyssal Plain, by New Zealand, by Norway in the North East Atlantic and the Arctic, by Mexico in Respect of the Western Polygon in the Gulf of Mexico, by United Kingdom of Great Britain and Northern Ireland in Respect of Ascension Island, by Indonesia in Respect of North West of Sumatra Island, by Suriname, by France in Respect of the Areas of the French Antilles and the Kerguelen Islands, by the Philippines in the Benham Rise Region, by Ghana, by Denmark in the Area North of the Faroe Islands, and by Pakistan, as well as the Joint Submissions by France, Ireland, Spain and the United Kingdom of Great Britain and Northern Ireland in the Area of the Celtic Sea and the Bay of Biscay, and by the Republic of Mauritius and the Republic of Seychelles. The Commission has completed the consideration of the submissions listed above and made recommendations thereon.

(2) To defer the consideration of a submission to some time later. There are cases where States concerned have delivered notes verbales in response to a submission, by invoking Article 5(a) of Annex I to the Rules of Procedure, but the submission is still waiting for its turn to be considered. Considering that the dispute is currently being or will likely be solved by the States concerned, the Commission would decide not to consider the submission for the time being, and may reconsiderit when its turn arrives; if the dispute remains unresolved when its turn comes, the submission may continue waiting until no protest is raised by the States concerned. For instance, the consideration of the Submission by Myanmar was put of f due to Bangladesh’s protest; the consideration of the Submission by Yemen in Respect of South East of Socotra Island was deferred because of Somalia’s opposition; the consideration of the Submission by Fiji was put of f owing to the objection from Vanuatu; and the consideration of the Submission by the United Kingdom of Great Britain and Northern Ireland in Respect of Hatton Rockall Area and the Submission by Ireland in Respect of Hatton Rockall Area was postponed due to the protest from Iceland and Denmark; the consideration of the Joint Submission by Malaysia and Viet Nam in the Southern Part of the South China Sea was put of f because China and the Philippines submitted notes verbales, expressing their opposing views; and the consideration of the Submission by Kenya was postponed because of Somali’s objections.

(3) To consider certain portion(s) of a submission. As described above, in cases where a submission fled by a coastal State concerns claims for territory in the Antarctic, or involves land or maritime disputes, the Commission will, on a case-by-case basis, not consider it or postpone its consideration, or only consider the portion free from disputes relating to the Antarctic and land or maritime disputes. For example, the Commission refused to consider the parts of Submission by Australia related to the Antarctic territory; it only chose to review nine regions, including Argo region, Great Australian Bight region, Kerguelen Plateau region, Lord Howe Rise region, Macquarie Ridge region, Naturaliste Plateau region, Three Kings Ridge region, and Wallaby and Exmouth Plateaus region. Plus, the Commission did not consider the portions of the Submission by Argentina associated with the Antarctic territory and the Malvinas Islands involving territorial disputes, merely deliberating the northern sector of Argentine passive continental margin and the western sector of the combined continental margin. In addition, the Commission decided not to consider, for now, the portion of the Submission by France in Respect of the Areas of French Guiana and New Caledonia that involved an area to the south east of New Caledonia, only to consider the area of French Guiana and the area to the south west of New Caledonia. Additionally, the portion of the Submission by Japan involving Okinotorishima Rocks has not been considered by the Commission, which merely examined and reviewed the Minami-Io To Island Region, the Minami-Tori Shima Island Region, the Mogi Seamount Region, the Ogasawara Plateau Region, the Southern Oki-Daito Ridge Region, andthe Shikoku Basin Region.⑤Fang Yinxia, Tang Yong and Fu Jie, Summary of Recommendations by the Commission on the Limits of the Continental Shelf with Regard to Japan’s Submission: A Commentary, China Oceans Law Review, No. 2, 2013, pp. 110～129.

IV. The Main Issues That the CLCS Examines during Its Consideration of Submissions

According to the Rules of Procedure, the full text of the recommendations proposed by the Commission on a submission is kept confdential; therefore, it is difficult for us to get a complete picture of the Commission’s deliberation of the submissions. However, the summaries of recommendations are duly publicized on the website of the United Nations, which can give us a rough idea of the deliberation of the submissions. A close look at the publicized summaries of recommendations shows that, when considering a submission, the Commission chiefy examines the following matters: whether it has the authority to consider the submission, the geological and geographical description of the region concerned, the natural prolongation of the land mass of the coastal State, and the determination of the location of the foot of the continental slope (FOS), the outer edge of the continental margin, and the outer limits of continental shelf. Upon the establishment of a subcommission, during its examination of submissions, the subcommission primarily evaluates the following issues: whether the base and the foot of the continental slope are appropriately located, whether the sediment thickness of 1% is reliably determined, whether the constraint line constructed at 100 nm from the 2500 metre isobaths is applicable, and whether the points on the 200 nm lines are appropriately identifed.

A. The Appropriateness of the Base and the Foot of the Continental Slope

The Commission recognizes the FOS as an important geomorphological feature. Plus, the two formulae lines employed to extend continental shelf under the UNCLOS are determined on the basis of the FOS. Therefore, the FOS serves as the basis for entitlement to the extended continental shelf and a critical factor to be reviewed by the Commission. Pursuant to the Scientifc and Technical Guidelines,the FOS can be established through two main methods. First, it may be identifed as the point of maximum change in the gradient at its base, based on the geological and geomorphological features of the continental margin. Second, evidence to the contrary to the general rule may be invoked to defne the location of the FOS. That is, the Commission may use the continental-oceanic transitional zone, which was determined on the basis of geological and geophysical evidence and other sources of evidence available, to locate the FOS, when the geomorphological evidence given by the maximum change in the gradient can not reliably locate the FOS. Currently, in almost all of the submissions which have been considered by the Commission, the frst method is applied to determine the FOS, that is, the point of maximum change in the gradient at its base is selected as the FOS.

When considering the Submission by the United Kingdom of Great Britain and Northern Ireland in Respect of Ascension Island, the Commission questioned the base of the continental slope and the location of the FOS established by the UK; however, the two parties failed to reach a consensus after communications. The UK regarded the rift valley of the spreading axis and the deeps of associated fracture zones as parts of the continental slope of Ascension Island. However, the Commission argued that ocean spreading structures, which were normally part of the deep ocean foor, could only form the continental slopes of island landmasses in cases where such structures formed part of the discrete seafoor highs from which the island edifces rose. This was not the case for Ascension Island, as its edifce was not morphologically connected to any such discrete seafloor high (Fig. 2). The recommendations provided by the Commission pointed out that, the rugged seafloor between the Ascension Island volcanic edifice and the axis of the Mid-Atlantic Ridge was part of the normal deep ocean foor, rather than the continental shelf of the Ascension Island. As a result, the FOS identifed by the UK in this area was rejected by the Commission.⑥At http://www.un.org/Depts/los/clcs_new/submissions_fles/gbr08/gbr_asc_isl_rec_summ. pdf, 18 October 2016.

Fig. 2 The Location Map of the FOS of Ascension Island Recommended by the CLCS17

B. The Reliability of the Sediment Thickness of 1%

The sediment thickness rule is one of two equally valid formulae for entitlement to the extended continental shelf and the delineation of its outer limits. In this connection, the Commission conducts strict examinations. The determination of the sediment thickness formula line relates to the identifcation of the sediment/ basement interface, the calculation of sediment thickness and the variability of sediment distribution, as well as other technical issues. The thickness of sediments can be determined by means of direct sampling and indirect methods. Since direct sampling, such as drilling, is very costly, presently, the sediment thickness, in all the submissions filed to the Commission, is indirectly calculated from seismic data. This method involves issues like the identification of the sediment, the reliability of velocity analysis, and depth conversion. In this case, because of uncertainties involved in the procedure, inaccuracies in sediment thickness could typically be 10%. For example, when deliberating the Submission by Barbados, the Commission objected to the position of Gardiner point 12 (GP12) identified in the submission. Considering large extrapolation distances were involved in the Barbados’ determination of Gardiner point, the Commission requested that Barbados provide any additional data available to support the extrapolation. In this case, Barbados utilized the information from a new sonobuoy to provide additional support for the extrapolation of the velocity model and of f ered a revised location of GP12 determined on the basis of a seismic line. Eventually, this relocated GP12was approved by the Commission.⑧At http://www.un.org/Depts/los/clcs_new/submissions_fles/brb_10rev2011/brb_10rev2011 _summary_recommendations.pdf, 18 October 2016.

C. The Applicability of the Constraint Line Constructed at 100 NM from the 2500 Metre Isobath

Article 76 of UNCLOS sub-classed the highs into three legal types: oceanic ridges of the deep ocean foor, submarine ridges, and submarine elevations, each of which has a dif f erent entitlement to continental shelf. Specifcally, oceanic ridges of the deep ocean foor are not entitled to an extended continental shelf. In the case of submarine ridges, the outer limit of the continental shelf shall not exceed 350 nm from the baselines from which the breadth of the territorial sea is measured. Furthermore, in the case of submarine elevations that are natural components of the continental margin, the continental shelf can extend up to 350 nm from the baselines or 100 nm from the 2,500 metre isobath. Article 76 prescribed the entitlement to continental shelf for these three types of ridges; however, it failed to provide precise defnitions for the three terms or an exact method to distinguish them. Due to the uncertainty in the UNCLOS provisions concerning ridges, Scientifc and Technical Guidelines also failed to of f er a fnal solution, which has attracted the attention of many scholars. For example, Symonds, a former member of CLCS, and other scholars, when discussing the UNCLOS provision with respect to ridges, classified ridges into two categories: ridges in divergent settings and ridges in convergent settings. They contended that the classification of ridges should take into account the geological origins and tectonic settings of the ridges, along with other geological factors.⑨Philip A. Symonds, Mike F. Coffin, George Taft and Hideo Kagami, Ridge Issues, in Peter J. Cook and Chris M. Carleton eds., Continental Shelf Limits: The Scientific and Legal Interface, New York: Oxford University Press, 2000, pp. 285～307.In contrast, Brekke, also a former member of CLCS, when classifying the ridges, did not consider the geological forming process of ridges, but he did take note of the locations of ridges related to the continental margin.⑩Harald Brekke and Philip A. Symonds, The Ridge Provisions of Article 76 of the UN Convention on the Law of the Sea, in Myron H. Nordquist, John Norton Moore and Tomas H. Heidar eds., Legal and Scientific Aspects of Continental Shelf Limits, Leiden/Boston: Martinus Nijhof f Publishers, 2004, pp. 169～199.The provisions of UNCLOS should be interpreted in good faith. In this connection, the authors believe that only the ridges which are continuous, bothin morphology and geology with the land mass and submerged prolongation of a coastal State, are submarine elevations. Ridges which are discontinuous in morphology with the continental margins are oceanic ridges. Those ridges which are continuous in morphology, but discontinuous in geology, are submarine ridges.①Wang Weiguo, Geological Structures of Ridges with Relation to the Definition of Three Types of Seafoor Highs Stipulated in Article 76, Acta Oceanologica Sinica, Vol. 30, No. 5, 2011, pp. 125～137.Currently, given that ridges are not precisely defned, we cannot fnd any clear principles and methods to identify them. Besides, when treating submissions made by different States, the Commission’s views are not completely consistent with respect to the issue of the features of ridges.

For example, during the consideration of the Submission by Australia, the Commission questioned whether the Williams Ridge and the Joey Rise could be classifed as submarine elevations in the sense of UNCLOS Article 76. Since the data submitted for the Williams Ridge and Joey Rise gave only indirect evidence of their natures and origins, the Commission held that their geological origin still remained unresolved and they should not be recognized as submarine elevations. Additionally, the Commission did not agree with the location of the fxed points on continental shelf outer limit line, established by Australia, in accordance with constraint lines at 100 nm from the 2500 metre isobath.②At http://www.un.org/Depts/los/clcs_new/submissions_fles/aus04/Aus_Recommendations_ FINAL.pdf, 18 October 2016.This example shows that the Commission, when evaluating the three types of ridges above, took into account both morphological and geological continuity, which is consistent with the original purpose of UNCLOS, to provide that different types of ridges have different entitlements to continental shelf.

D. The Appropriateness of the Points on the 200 NM Lines

Article 76(7) of the UNCLOS states that, the coastal State shall delineate the outer limits of its continental shelf, where that shelf extends beyond 200 nm from the baselines from which the breadth of the territorial sea is measured, by straight lines not exceeding 60 nm in length, connecting fxed points, defned by coordinates of latitude and longitude. Based on the article, in order to maximize its benefts, Australia, in its submission, used lines not more than 60 nm in length to join fixed points on the formula line to any fixed point on the 200 nm line todelineate the outer limits of its continental shelf in each region it claimed. However, the Commission was of the view that this extended continental shelf delineated by Australia exceeded the limits provided for in UNCLOS. The Commission stated that the determination of the last fxed point of the outer limits of the continental shelf should be established by the intersection of the formula line and the 200 nm line. Consequently, the Commission disagreed with the determination of the points on the 200 nm line in all the regions submitted by Australia in its submission. In a similar manner, the Commission held that, in the Macquarie Ridge Region and the Three Kings Ridge Region, Australia should not use straight lines not exceeding 60 nm in length to determine the points on the Australian-New Zealand boundary line.③At http://www.un.org/Depts/los/clcs_new/submissions_fles/aus04/Aus_Recommendations_ FINAL.pdf, 18 October 2016.

E. The Appropriateness of the Points beyond the 350 NM Lines

This factor is mainly considered in joint submissions. When reviewing the Joint Submission by France, Ireland, Spain and the United Kingdom of Great Britain and Northern Ireland, the Commission noted that the proposed fixed point FP 30 was located within the Spanish 350 nm constraint line but beyond all other 350 nm constraint lines. Further, the Commission contended that FP 30 was determined based on the extension of the Irish, rather than the Spanish, continental margin; therefore, it should be subject to the 350 nm line constructed from the baselines from which the territorial sea of Ireland was measured. As a result, the point FP 30 should lie within or on the Irish 350 nm constraint line. Following the Commission’s recommendation, the four coastal States revised their outer limits, which were eventually approved by the Commission after deliberation.④At http://www.un.org/Depts/los/clcs_new/submissions_fles/frgbires06/fsu_clcs_recommen dations_summary2009.pdf, 18 October 2016.

V. Features and Development Tendency of Extended Continental Shelf Delineation

Abundant natural resources can be found on the extended continental shelf. And UNCLOS Article 77(1) explicitly provides that “the coastal State exercisesover the continental shelf sovereign rights for purpose of exploring it and exploiting its natural resources.” Obviously, the delineation of the outer limits of the continental shelf beyond 200 nm, pertains to the sovereign rights of coastal States and also directly relates to their economic benefts. Due to the rich natural resources on the extended continental shelf, and the ef f ect of declaring sovereignty that may arise from the fling of submissions, States have taken the application for extended continental shelf more and more seriously and invested more deeply in this cause known as “Blue Enclosure Movement”. Especially in the 15 years since Russia made the frst submission to the CLCS in 2001, state practice with regards to the delineation of extended continental shelf and the modes in which the Commission considers submissions have developed gradually. In terms of state practice, initially, coastal States rushed to present their submissions in order to meet the deadline, but now, more and more States are taking the initiatives to protect, in an all-round and multi-level way, their maritime rights and interests, through fling submissions to the CLCS, which has highlighted and also in some ways exacerbated the maritime delimitation disputes in the world. In terms of the practice of the Commission, the procedures and the rules of the Commission to consider and review the submissions have gradually become stable and fxed, which in turn af f ect, more or less, state practice in respect of extended continental shelf delineation. Overall, the practice with regards to extended continental shelf delineation in the world has shown the following features.

A. Large Overlapping Claims

The 77 submissions as received by the CLCS exhibit serious overlapping claims of extended continental shelves. The areas claimed by 47 dif f erent States are overlapping to varied degrees (Table 1), and some are seriously overlapping. For example, the extended continental shelves claimed by Bangladesh, India, Myanmar and Sri Lanka, in the Bay of Bengal, almost overlap completely. Additionally, the continental shelf claimed by the UK for the Malvinas Islands is almost fully overlapping with the one claimed by Argentina, and the continental shelves in the Hatton Rockall Area claimed by the UK, Ireland, Iceland and Demark are also overlapping. In the case of the East China Sea, apart from the Sino-Japanese disputes centered on the sovereignty of Diaoyu Islands, South Korea also raised its claim to an extended continental shelf in this area. In the South China Sea, bordering States, including China, Viet Nam, Malaysia and the Philippines, havedisputes centered on the sovereignty of the Nansha Islands. In practice, these overlapping claims are originated from the sovereignty disputes and maritime delimitation conflicts that have already existed in these sea areas, which have resurfaced by virtue of extended continental shelf delineation. The Commission definitely will not consider some disputable submissions. Nevertheless, the submitting State has achieved the purpose of declaring its sovereignty by filing submissions before the Commission, whether its submissions would be considered or not. In this sense, declaration of sovereignty could be said to be one of the main reasons that compel the coastal State to forward submissions to the Commission.

Table 1 Statistics on the Overlapping Claims for Extended Continental Shelves

18Ghana vs. NigeriaGulf of Guinea 19Kenya vs. SomaliaContinental Margin of East Africa 20Maldives vs. Sri LankaNorth Atlantic 21Bengal vs. Burma vs. Sri Lanka vs. IndiaBay of Bengal 22Mozambique vs. South AfricaSouthwest Indian Ocean 23Portugal vs. SpainNorthern Waters of f Canary Islands 24Portugal vs. Seven West African StatesSouthern Waters of f Canary Islands 25Japan vs. PalauPhilippine Sea 26Somalia vs. TanzaniaContinental Margin of East Africa 27Somalia vs. YemenContinental Margin of East Africa 28China vs. KoreaEast China Sea

B. Many States Choose to Make Partial or Joint Submissions

Considering the serious overlapping claims, in practice, if a submission involves delimitation disputes or other relevant maritime or land disputes, the States concerned would deliver notes verbales to express their concerns or protests, which suffice to prevent the Commission from reviewing the submissions involving such disputes. Rule 3 of Annex I to the Rules of Procedure states that a submission may be made by a coastal State for a portion of its continental shelf in order not to prejudice questions relating to the delimitation of boundaries between States in any other portion or portions of the continental shelf. This rule encouraged some coastal States to frst fle a submission for the portion of continental shelf free from disputes in order to avoid causing disputes and conficts with neighboring States. Hence, it is not surprising to fnd that, up to now, 46 partial submissions have been fled, which accounts for 60% of the 77 submissions received by the Commission.

Apart from avoiding disputes, partial submissions, which have acquired the full attention of the submitting States, have more of a chance to get approved by the Commission. The delineation of extended continental shelves relates to complex legal, scientifc and technical issues. Given the discrepancy of scientifc understanding on an issue, any submission, in theory, is inevitably uncertain to some extent. However, if the claims of a submitting State dif f er from the views held by subcommission after deliberation, it would be difficult for the submission to get approved by the Commission, unless that State provides sufficient evidence. In thiscase, undoubtedly, it is wise for States to first make submissions for the portion of continental shelf in which evidence is sufficient, especially for the developing States inficted with scientifc, technical, fnancial and other problems.

C. The Delineation of Antarctic and Arctic Continental Shelves Has Generated Widespread Concerns

Seven States, including Australia, New Zealand, Argentina, Chile, France, the UK and Norway, have officially claimed territory in the Antarctic, primarily the sector-area between 60º South Latitude and the South Pole. Up to now, those States, excluding Chile, which has submitted the preliminary information indicative of the outer limits of its continental shelf beyond 200 nm, have officially presented their submissions or partial submissions to the Commission. Particularly, three States (Australia, Norway and Argentina) in their submissions, raised express claims to the Antarctic territorial sovereignty and continental shelf, and some of the continental shelves claimed by Australia, Argentina and the UK extended to the area south of 60º South Latitude, which is the area where the Antarctic Treaty System applies. UNCLOS established a 12 nm territorial sea and 200 nm exclusive economic zone, and created and developed the regimes of continental shelf and international seabed area. Nevertheless, the existing legal provisions under the Antarctic Treaty System would surely be challenged or impaired if these regimes are applied to the Antarctic region infexibly.

The legal regimes with respect to the Arctic dif f er from those of the Antarctic in that no complete treaty system is in place for the former. The current legal rules concerning the Arctic can merely be employed to address some specifc problems. Regrettably, no law governs the Arctic region or the Arctic Ocean as a whole. There are primarily eight States bordering the Arctic Ocean: Russia, Canada, the United States, Denmark, Norway, Finland, Sweden and Iceland. However, the coastal States of the Arctic Ocean, in a true sense, only include the so-called“Arctic Five”, namely, Russia, Canada, Denmark, Norway and the United States. Except for the United States, the other four members of the Arctic Five are States Parties to UNCLOS. Russia, Norway and Demark have all made their submissions involving the Arctic Ocean to the Commission (Fig. 3). Russia’s submission was disapproved by the Commission in 2002 due to the lack of sufficient scientific evidence in the eyes of the Commission. Nonetheless, in the last 10 years, Russia has carried out large-scale scientifc surveys in the Arctic Ocean, and it presentedits revised submission in August 2015 to the Commission, based on a great amount of geological and geophysical evidence obtained from these surveys. Noticeably, Russia claimed larger extended continental shelves in the revised submission than in the original one. The part of Norway’s submission involving the Arctic continental shelf was associated with Svalbard. This submission has been approved by the Commission. Likewise, Denmark made two submissions in respect of the northeastern and northern continental shelves of Greenland. Particularly, in the submission in respect of the northern continental shelf of Greenland, submitted in December 2014, the outer limits of the continental shelf claimed by Denmarkextended to the 200 nm line of Russia through the North Pole. Additionally, Canada alleges that it has completed the preparation of its submission with respect to the Arctic Ocean and will forward it to the Commission in the near future, when the time is right. Although the United States has not yet ratifed or acceded to UNCLOS, it absolutely will not renounce the rights to extend its continental shelves. Under this circumstance, accompanying the fling of submissions by the members of Arctic Five, the scramble for extended continental shelves in the Arctic Ocean would be increasingly ferce.

Fig. 3 The Situation Concerning the Delimitation ofExtended Continental Shelves in the Arctic Ocean

D. The Ridge Rule Is the Most Complex Issue in the Delineation of Extended Continental Shelves

Sea floor highs are extensively spread across many deep sea basins and continental margins, accounting for more than 33% of the total area of the oceans. As stated above, when defining continental shelf, UNCLOS, after considering all kinds of ridges and their relationship with shelf area, sub-classed these ridges into three types - oceanic ridges of the deep ocean floor, submarine ridges and submarine elevations, and provided for their entitlement to continental shelves. Due to the diversity of ridges and their complex geological features, as well as the lack of a precise and scientifc defnition for the three terms above or an explicit method to identify them under UNCLOS, the issue of ridges becomes the most complex one in the actual delineation of extended continental shelves. It also gives a coastal State opportunities to maximize its own interests by invoking the ridge rule. In all of the submissions fled, the overwhelming majority of submitting States have treated all kinds of ridges with various geological origins, like oceanic ridges, submarine ridges, rises, seamounts and plateaux, as submarine elevations that are natural components of the continental margin, intending to extend their continental shelves to the maximum extent, even to the area that is the component of the international seabed area. However, this act will jeopardize the common interests of humankind.

Currently, the application of the ridge rule has been widely discussed in academic circles, and preliminary consensus on this issue has been reached. Nonetheless, in practice, how to defne the nature of ridges still involves complex issues. When considering submissions, the Commission always takes a case-bycase approach to deal with the parts associated with ridges, and the principles it adopts to identify all kinds of ridges are not completely consistent. Theresults of the consideration of submissions by CLCS reveal the following facts: microcontinents broken off from main continental masses, by virtue of their ancient continental crusts, are considered submarine elevations, regardless of their sizes; mid-ocean ridges formed by sea-floor spreading are generally recognized as oceanic ridges of the deep ocean foor, since they are oceanic crusts in nature. However, the identification of complex ridges with various geological origins is much more complicated and controversial, especially the ridges and accreted ridges along the convergent continental margins. In addition, when examining the entitlement to continental shelf for dif f erent types of ridges, the Commission also took into account the geological and geomorphological features of ridges and their geological nature, along with available geological and geophysical evidence. With respect to ridges with obvious crustal nature and sufficient geological evidence, the Commission would first consider the geological continuity of the ridges; however, for ridges with complex crustal compositions and origins, the Commission often only chooses to consider the continuity in morphology. On the whole, the Commission has adhered to the basic rules under UNCLOS and been compatible with the original purpose of UNCLOS, to provide different entitlements to continental shelf for dif f erent types of ridges. Also, it has conducted strict examinations in each phase of its work so that justice and equity, as well as international stability, are maintained and the interests of international seabed area are protected, which would definitely have far-reaching influence on future maritime delimitation in the world.

VI. Conclusion

The delineation of continental shelves beyond 200 nm means to draw the outer limits of the continental shelves of the coastal States, by invoking the regime of continental shelf under UNCLOS, which involves a convergence of science and law. The complex geomorphology and geological feature of the global continental margin, along with the different historical and legal relations between coastal States, gave rise to the complicated and diverse submissions that have been fled to the CLCS. At present, to delineate the outer limits of its extended continental shelf, is a pretext or great opportunity that a coastal State may use to legally expand its jurisdiction in accordance with UNCLOS. A close look at the submissions made in the last 15 years shows that the majority of coastal States have tried their utmost to expound and extend the meaning of the relevant rules and articles under theUNCLOS, pursuing to maximize the areas of their continental shelves. Therefore, new scientifc and legal issues emerged one after another during the consideration of submissions, particularly concerning the application of the ridge rule.

State practices, with respect to continental shelf delineation and the Commission’s consideration of submissions, are essential in addressing scientifc and legal issues pertaining to the delineation of extended continental shelf. The basic rules, primary methodology, supporting data and evidence, and other materials used by coastal States in their submissions, together with the main principles adopted, the critical issues reviewed, and the recommendations and reasons given by the Commission, could provide references and a legal basis for future delineation of continental shelf and consideration of submissions. Hence, bigger ef f orts should be invested in the study of relevant scientifc, technical and legal issues, and the latest developments regarding the theories and practice of the continental shelf regime should be learned and summarized in a timely manner, which could be used for reference by China in the delineation of its extended continental shelf, or when China’s maritime rights and interests are undermined by other States’ claims of continental shelf.

Translator: XIE Hongyue

Editor (English): Hewitt Ashley Nicole

The Progress and Situation of Extended Continental Shelf Delineation Worldwide

FANG Yinxia*YIN Jie**TANG Yong***LI Jinrong****

In 2001, Russia made the first submission, containing proposed outer limits of its continental shelf beyond 200 nautical miles (nm) from the baselines from which the breadth of the territorial sea is measured, to the Commission on the Limits of the Continental Shelf (CLCS). As of 30 June 2016, the CLCS had received 81 submissions and had reviewed and released recommendations on 24 of them. After systematically outlining the situation of the submissions that have been, are being, or will be fled by States, the modes that CLCS adopts to treat submissions, and the primary issues that the CLCS examines during its consideration of submissions, this paper explores, from both scientific and legal perspectives, the features of current practice with respect to extended continental shelf delineation, as well as its development tendency. In this context, this paper suggests that greater ef f orts should be invested in the study of relevant scientifc, technical and legal issues, and the latest developments regarding the theories and practice of the continental shelf regime should be learned and summarized in a timely manner, which could be used for reference by China in the delineation of its extended continental shelf, or when China’s maritime rights and interests are undermined by other States’ claims of continental shelf.

Continental shelf beyond 200 nm; Submission; Commission onthe Limits of the Continental Shelf (CLCS); Recommendations of the CLCS

* 方银霞，国家海洋局第二海洋研究所专属经济区与大陆架研究中心研究员，电子邮箱：fangyx@sio.org.cn。本文获海洋公益性行业科研专项经费资助项目（编号：201205003）和国家自然科学基金项目（编号：41476048和41401142）资助。

** 尹洁，国家海洋局第二海洋研究所专属经济区与大陆架研究中心助理研究员。

*** 唐勇，国家海洋局第二海洋研究所专属经济区与大陆架研究中心研究员。

**** 李金蓉，国家海洋信息中心，助理研究员。

© THE AUTHORS AND CHINA OCEANS LAW REVIEW

⑦ At http://www.un.org/Depts/los/clcs_new/submissions_fles/gbr08/gbr_asc_isl_rec_summ. pdf, 18 October 2016.

* FANG Yinxia, research fellow, Research Center on Exclusive Economic Zones and Continental Shelves at the Second National Institute of Oceanography, State Oceanic Administration (SOA). Email: fangyx@sio.org.cn. This article is funded by the Ocean Public Welfare Scientifc Research Special Appropriation Project (No: 201205003) and two Programs of National Natural Science Foundation of China (Nos. 41476048 and 41401142).

** YIN Jie, assistant research fellow, Research Center on Exclusive Economic Zones and Continental Shelves at the Second National Institute of Oceanography, SOA.

*** TANG Yong, research fellow, Research Center on Exclusive Economic Zones and Continental Shelves at the Second National Institute of Oceanography, SOA.

**** LI Jinrong, assistant research fellow, National Marine Data and Information Service.

© THE AUTHORS AND CHINA OCEANS LAW REVIEW

⑦ At http://www.un.org/Depts/los/clcs_new/submissions_fles/gbr08/gbr_asc_isl_rec_summ. pdf, 18 October 2016.