Geographical analysis in maritime boundary delimitation

Transcription

1 Geographical analysis in maritime boundary delimitation Martin Pratt International Boundaries Research Unit Durham University, UK 1 Abstract Nearly one third of the earth s ocean area is now under coastal state jurisdiction, creating more than 430 international maritime boundaries fewer than half of which have been even partially defined. Wherever maritime boundaries remain uncertain there is likely to be competition for marine resources, which can all too easily escalate into serious international conflict. As the global demand for energy resources increases and the technology for deep-water drilling advances, the need for clearly-defined maritime boundaries has never been greater. The only requirement in international law for maritime boundary delimitation beyond the territorial sea is that an equitable solution is achieved, which means that states seeking to define their maritime boundaries are faced with a wide range of options. In practice, coastal geography is normally the key element in identifying an equitable division of maritime space, with the length and configuration of the relevant coastlines being particularly significant. This paper explores the kind of geographical analysis that needs to be undertaken when preparing for maritime boundary delimitation, and highlight ways in which CARIS LOTS can facilitate such analysis. Introduction Under the 1982 United Nations Convention on the Law of the Sea (UNCLOS) a coastal state is entitled to claim a sovereign territorial sea extending up to 12 nautical miles (nm 2 ) from its coastal baselines, a contiguous zone adjacent to the territorial sea extending up to 24 nm from the baselines 3, and an exclusive economic zone (EEZ) extending up to 200 nm from the baselines. 4 Depending on the extent of the continental margin, the state may also be able to claim rights over the resources of the continental shelf beyond 200 nm. Since states have different rights and responsibilities in these various jurisdictional zones, it is important that the state claiming the zones defines and publicises their limits. However, surprisingly few states have done so International Boundaries Research Unit, Department of Geography, Durham University, Durham DH1 3LE, UK. Tel: Fax: ibru@durham.ac.uk Web: 1 nautical mile = 1,852 metres. There is no internationally-agreed abbreviation for a nautical mile. As well as nm, M, NM, Nm and nmi are all widely used. In its contiguous zone the coastal state may exercise the control necessary to prevent and/or punish infringement of customs, fiscal, immigration and sanitary laws within its territorial sea. In the EEZ the coastal state has sovereign rights for the purpose of exploring and exploiting, conserving and managing the natural resources, whether living or non-living, of the waters superadjacent to the seabed and of the seabed and its subsoil, and with regard to other activities for the economic exploitation and exploration of the zone, such as the production of energy from the water, currents and winds. Other rights and responsibilities in the EEZ are set out in Part V of UNCLOS. For the EEZ and continental shelf, UNCLOS requires that the limits of the zones are defined using a list of geographical coordinates or are shown on charts of a scale or scales adequate for ascertaining their position. For the territorial sea, either the limit or the baseline from which it is measured must be defined or depicted on suitable

2 Where the jurisdictional zones of neighbouring states overlap, the states in question also need to delimit boundaries between their respective zones. Every coastal state has at least one maritime boundary with a neighbouring state, and nearly 60% have four or more discrete boundary segments. If its overseas possessions are taken into account, France has a remarkable 50 potential maritime boundary segments to delimit! Counting the number of agreed maritime boundaries is not as straightforward a task as it might first appear. Many boundary agreements only cover part of the potential length of the boundary or only relate to one particular jurisdictional zone. Quite a few agreements have been signed but have yet to enter into force for one reason or another. Others are of questionable legitimacy because third states also claim rights in the area in which the boundary has been established. What can be stated with confidence, however, is that fewer than half of the 434 potential international maritime boundaries have even been partially agreed. 6 Why have so many maritime limits and boundaries yet to be defined? With limits, the answer often lies in the fact that the limit of a particular zone will be the boundary with a neighbouring state, and one or both parties may be reluctant to reveal their claims prior to entering into boundary negotiations. With boundaries, there may be many reasons for the failure to conclude an agreement. For some states, the division of maritime space is simply a very low priority compared to other development-related tasks. Sometimes the existence of a sovereignty dispute over coastal territory and/or offshore islands precludes the possibility of defining a boundary through the waters affected by the disputed territory. In other cases, the states involved have very different views of what represents an equitable division of maritime space and find it impossible to agree on where the boundary should run. Whatever the reason, the absence of defined limits and agreed boundaries can be a source of concern and frustration to a wide range of interest groups including oil and gas companies, pipeline and cable layers, fishermen, and organisations working to conserve ocean resources and protect the marine environment. The International Boundaries Research Unit (IBRU) works to enhance the resources available for the peaceful resolution of problems associated with international boundaries on land and sea around the world. One area in which IBRU s advice is regularly sought is the identification of potential jurisdictional limits and maritime boundaries where they have yet to be defined by coastal states. In this paper we examine key geographical aspects of 6 charts. The coastal state is required to give due publicity to such information and to deposit copies of the relevant charts or lists of coordinates with the Secretary-General of the United Nations (UNCLOS Articles 16, 75 and 84). Unfortunately, to date only around 25% of states parties to UNCLOS have even partially fulfilled this obligation. The figure of 434 potential maritime boundaries assumes (i) that boundaries that have yet to be agreed will follow median lines, and (ii) that discrete boundary segments are counted as separate boundaries. If discrete boundary segments are counted as parts of a single maritime boundary (e.g. if Canada and the USA were said to have one maritime boundary rather than four maritime boundaries) then the number of potential boundaries would fall to 366. At its most recent counted, IBRU identified 210 out of 434 (or 168 out of 366) maritime boundaries with at least one signed agreement relating to the definition of the boundary. Geographical analysis in maritime boundary delimitation 2

3 maritime boundary delimitation, and explain how the Limits and Boundaries version of CARIS LOTS can assist in the definition and analysis of maritime limits and boundaries. 7 Identifying jurisdictional limits Once the baseline from which the breadth of maritime zones is measured has been defined, LOTS makes the identification of the limit of a zone defined as extending a particular distance from the baseline a very simple task. LOTS examines every point used to define the baseline and determines which points contribute to the envelope of arcs which defines the outer limit of the zone. While most GIS packages are able to generate buffers a set distance from a specified line, most only do so using planimetric rather than geodetic measurements, making them unsuitable for defining maritime limits. As far as this author is aware, LOTS is unique among commercially available software tools in its capacity to generate geodetic buffers which define maritime limits accurately on a specified reference ellipsoid. Schematic illustration of how an envelope of arcs is used to generate a maritime limit (Source: CARIS LOTS Interface Guide) Although coastal states are entitled to draw straight baselines across the mouths of rivers and some bays 8, and along coastlines which are fringed with islands and/or are deeply indented or cut into, the normal baseline from which maritime zones are measured is the low-water line marked on large-scale charts officially recognised by the coastal state. In order to define a state s maritime limits with precision, it is therefore often necessary to identify the points along the low-water line which contribute to the outer limit of a particular zone. This can be achieved either by digitising the entire low-water line a tedious and time-consuming task or by making use of LOTS ingenious wagon-wheel filter, which allows the user to roll a circle with a specified radius (e.g. 12 nm or 200 nm) along the low-water line depicted on a georeferenced raster chart, and place a basepoint marker at every point where the circle comes into contact with the low-water line. Where a coastline is very smooth, the wagon- 7 8 The full version of CARIS LOTS also contains a suite of tools designed to assist in the complex task of defining the outer limit of the continental shelf beyond 200 nm from the baseline. These tools are not discussed in this paper. LOTS includes a very useful tool for determining whether a bay can legally be defined as internal waters through the application of a closing line (or lines). Geographical analysis in maritime boundary delimitation 3

4 wheel filter can be difficult to use with precision, but for many coastlines it can save hours of unnecessary digitising. Schematic illustration of the wagon wheel filter (Source: CARIS LOTS Interface Guide) Identification of basepoints contributing to the 12 and 200 nautical mile limits off the south coast of Tasmania. Points contributing to both limits are highlighted in red. Geographical analysis in maritime boundary delimitation 4

5 Identifying maritime boundaries Identifying potential maritime boundaries is a much more challenging task than identifying the limits of a maritime zone. Indeed, it is impossible to predict the alignment of an as-yet undelimited maritime boundary with 100% confidence because there are no formal rules for maritime boundary delimitation. In fact UNCLOS actually contains only five paragraphs of guidance on the subject. For territorial sea boundaries, the guidance is quite prescriptive: Article 15 provides that, unless the states agree otherwise or there exists historic title or other special circumstances in the area to be delimited, neither state is entitled to extend its territorial sea beyond the median line, which is defined as the line every point of which is equidistant from the nearest points on the baselines from which the breadth of the territorial seas of the two states is measured. For continental shelf and EEZ boundaries, however, the guidance boils down to a simple requirement that delimitation shall be effected by agreement on the basis of international law in order to achieve an equitable solution. 9 Since the convention is completely silent about what constitutes an equitable solution, states are free to agree any boundary they choose and the term is clearly open to widely varying interpretations depending on the interest of the states involved. The significance of the median line Fortunately for analysts, in recent years the International Court of Justice (ICJ) and arbitration tribunals charged with delimiting maritime boundaries have employed a consistent methodology in delimiting continental shelf and EEZ boundaries: first they have identified the median line between the two coasts, and then they have examined whether any circumstances exist which justify a departure from the median line in order to produce an equitable solution. While there is no obligation for states to follow the same procedure in negotiations, the more consistent the jurisprudence becomes, the harder it will be to justify alternative approaches in the event of disagreement. Thus for both the territorial sea and the resource zones that lie beyond it, the median line is an essential line to identify as a starting point for analysis and arguably for boundary delimitation itself. Since the median line is a geometric construct the line every point of which is equidistant from the nearest points on the baselines from which the breadth of the territorial seas of the two states is measured its alignment can be computed with geodetic precision as long as the two baselines are correctly defined. LOTS not only provides a user-friendly tool for generating the median line between two baselines, it can also indicate which basepoints along the two coastlines control the different segments of the median line. 9 UNCLOS Articles 74 and 83. Geographical analysis in maritime boundary delimitation 5

6 The median line between two coastlines showing the which basepoints control different sections of the line. Evaluating equity Understanding how a median line is constructed can be very useful in terms of assessing whether the median line is an equitable solution. Over the years a wide range of economic, security and environmental issues have been cited as relevant factors in maritime delimitation. However, in general it is coastal geography in particular the length and configuration of the coastlines involved, and the location and size of islands that is the central factor in what might be termed the equitability equation. By examining the control lines for the median line, it is possible to tell at a glance whether particular headlands or small islands have a disproportionate influence on the alignment of the median line. If they do, a judicial body may well decide to give the features in question reduced effect in the construction of the median line in order to produce an equitable division of maritime space. Calculating reduced effect Two methods are available for giving reduced effect to certain coastal features. The one that has generally been employed by the ICJ and arbitration tribunals is to give a feature half effect by generating two median lines, one giving full effect to the feature in question and one ignoring it altogether, and then generating a median line between the two median lines. Quarter effect and three-quarters effect etc. can be achieved by constructing additional median lines between median lines. A more elegant approach from a computational perspective is the so-called equiratio method, in which different sections of coastline are assigned different weights in the construction of the median line. It is important to note that the two methods can produce quite different lines, and while the equiratio method is much Geographical analysis in maritime boundary delimitation 6

7 simpler to apply in LOTS, the fact that it has yet to be adopted in real maritime boundary delimitations means that it should probably be used with caution when examining potential delimitation scenarios. Comparison of two median lines giving half effect to the small island highlighted in orange. The red line is a median line between a full effect median line and a no effect median line; the green line is was generated using the equiratio method, giving the large island to the west of the boundary a weighting of 3 and the small orange island a weighting of 2. Evaluating proportionality Another important factor in evaluating equity is the concept of proportionality. Judicial bodies charged with delimiting maritime boundaries have consistently endorsed the opinion of the International Court of Justice in the North Sea Continental Shelf cases that an equitable delimitation requires a reasonable degree of proportionality between the extent of the continental shelf areas appertaining to the coastal State and the length of its coast measured in the general direction of the coastline. 10 This means that if the relevant coastlines of two states are of a similar length, they should expect to receive a broadly similar area of continental shelf; and if the relevant coastline of one state is significantly longer than that of its neighbour, it should expect to receive more than half of the area being delimited. However, while judicial bodies have regularly used proportionality to test the equitability of a proposed boundary, they have always made it clear that it should not be used as a basis for determining the boundary. The fact that State A s coastline is four times longer than State B s 10 North Sea Continental Shelf (Federal Republic of Germany/Denmark; Federal Republic of Germany/Netherlands) Judgment, 1969, paragraph 98. Geographical analysis in maritime boundary delimitation 7

8 does not mean that State A should automatically get four times as much continental shelf or EEZ as State B. Thus, while the principle of proportionality makes it possible to identify geographic circumstances in which a median line might produce an inequitable division of maritime space, it is difficult to predict exactly what kind of adjustment might be made in order to achieve an equitable outcome. Much is still left to the discretion of the judges and arbitrators tasked with delimiting the boundary in each particular geographical setting. GIS tools make it relatively straightforward to measure the coastline lengths of two states and to calculate the areas of maritime space that different maritime boundaries would assign to each of them. In principle, therefore, LOTS makes it easy to evaluate the proportionality of a given delimitation scenario. However, as yet there is no agreed methodology for determining what represents the relevant coastline for a proportionality calculation or, in many cases, for identifying the area that is actually being divided. In the case of coastline length, should every indentation along the coast be taken into account, or should only those sections of coastline which face on to the area to be delimited be considered? In terms of the relevant area, should the entire area of overlapping entitlements be part of the equation, or only the areas which lie directly in front of the adjacent or opposite coastlines? LOTS is of limited use in terms of answering such questions, although it can certainly facilitate a comparison of different methodological approaches which may help to determine which approach is preferable in a particular geographical setting. The impact of datums and type of line Somewhat remarkably, nearly half of all maritime boundary agreements to date fail to specify a reference datum for the coordinates of the turning points of the boundary, and around a third do not define the nature of the line segments. Such issues matter always matter to oil and gas companies, and sometimes they can impact significantly on other activities as well: when the USA and USSR entered into negotiations over their maritime boundary in the Bering Sea in 1977, the two governments agreed that the line defining the western limit of the territory purchased by the USA from Russia in 1867 should be the basis for the maritime boundary. However, the USA interpreted the 1867 line as being an arc of great circle, while the USSR understood it to be a loxodrome. The area between the two proposed lines was almost 21,000 square nautical miles! When the ICJ defined the maritime boundary between Cameroon and Nigeria in 2002, it neglected to indicate the datum to which the coordinates of the turning point of the boundary should refer. If the local Minna datum is used, the boundary would run approximately 75 metres west of where it would run if the coordinates are referred to WGS84 a significant distance in an oil-rich area. LOTS allows the analyst to compare the effect of using different reference datums where none is specified in an existing agreement, and of employing loxodromes rather than geodesics between turning points. Geographical analysis in maritime boundary delimitation 8

9 Conclusion Maritime boundary delimitation is fundamentally a political and legal process. However, legal experts regularly emphasise the importance of geography in the process: Nuno Antunes states emphatically that The key fact in maritime delimitation is coastal geography 11 ; and the late Professor Jonathan Charney noted in his introduction to International Maritime Boundaries that when states consider the facts and options available for maritime boundary delimitation, it is clear that primary attention will be placed upon the geography of the coastline. 12 In this context, it is hard to deny that there is a pressing need for geographical expertise on all sides in a maritime boundary delimitation and a sensible geographer will have a copy of CARIS LOTS in his or her toolkit. The software undoubtedly requires considerable practice to master, and it will only ever be of limited value to someone who is not familiar with the principles and nuances of maritime boundary delimitation. However, for anyone who has to grapple with the technical complexities of maritime jurisdiction on a regular basis, it is an essential resource N. Antunes, Towards the Conceptualisation of Maritime Delimitation: Legal and Technical Aspects of a Political Process (Leiden, Martinus Nijhoff, 2003), p.290. J.I. Charney, and L.M. Alexander, (eds) International Maritime Boundaries (Dordrecht, Martinus Nijhoff, 1993) Vol. 1, p. xliv. Geographical analysis in maritime boundary delimitation 9

10 Selected bibliography Antunes, N.M. (2000) The Importance of the Tidal Datum in the Definition of Maritime Limits and Boundaries, Maritime Briefing 2(7): Durham: International Boundaries Research Unit. Antunes, N.M. (2003) Towards the Conceptualisation of Maritime Delimitation: Legal and Technical Aspects of a Political Process, Leiden: Brill. Carleton, C. & C.H. Schofield (2001) Developments in the Technical Determination of Maritime Space: Charts, Datums, Baselines, Maritime Zones and Limits, Maritime Briefing 3(3): Durham: International Boundaries Research Unit. Carleton, C. & C.H. Schofield (2002) Developments in the Technical Determination of Maritime Space: Delimitation, Dispute Resolution, Geographic Information Systems and the Role of the Technical Expert, Maritime Briefing 3(4): Durham: International Boundaries Research Unit. Charney, J.I. & L.M. Alexander (eds) (1993/1998) International Maritime Boundaries Vols. I-III, Dordrecht: Martinus Nijhoff. Charney, J.I. & R.W. Smith (eds) (2002) International Maritime Boundaries Vol. IV, The Hague: Martinus Nijhoff. Colson, D.A. & R.W. Smith (eds) (2005) International Maritime Boundaries Vol. V, Leiden: Martinus Nijhoff. Evans, M.D. (1989) Relevant Circumstances and Maritime Delimitation, Oxford: Clarendon Press. Francalanci, G. and T. Scovazzi (eds) (1994) Lines in the Sea, Dordrecht: Martinus Nijhoff. International Hydrographic Organization (1993) A Manual on Technical Aspects of the United Nations Convention on the Law of the Sea, Monaco: International Hydrographic Bureau. Lathrop, C. (1997) The technical aspects of international boundary delimitation, depiction and recovery, Ocean Development and International Law 28. Lagoni, R. and D. Vignes (eds) (2006) Maritime Delimitation, Leiden: Martinus Nijhoff. Pratt, M.A. (ed) ( ) Jane s Exclusive Economic Zones yearbook, Coulsdon: Jane s Information Group Pratt, M.A. and Smith, D.W. (2007) How to deal with maritime boundary uncertainty in oil and gas exploration and production areas, Association of International Petroleum Negotiators Research Papers. Pratt. M.A. (2007): Lines in the sea: technical challenges in maritime boundary delimitation, Hydro International 11(4) Prescott, J.R.V. and C.H. Schofield (2005) The Maritime Political Boundaries of the World, Second Edition, Leiden: Martinus Nijhoff. Smith, R.W. (1982) A geographical primer to maritime boundary-making Ocean Development and International Law 12. Symmons, C. (1995) Some Problems Relating to the Definition of Insular Formations in International Law: Islands and Low-Tide Elevations, Maritime Briefing 1(5), Durham: International Boundaries Research Unit. Tanaka, Y. (2006) Predictability and Flexibility in the Law of Maritime Delimitation, Oxford: Hart Publishing. Thamsborg, M., In Search of an Objective Approach to the Identification of Certain Geographical Parameters: The Jan Mayen Case Before the International Court of Justice, Nordic Journal of International Law 64 (1995), United Nations Division of Ocean Affairs (2000) Handbook on the Delimitation of Maritime Boundaries, New York: United Nations. Geographical analysis in maritime boundary delimitation 10