LEGAL, LOGICAL, AND GEOLOGICAL BOUNDARIES OF THE AUSTRALIAN CONTINENT

Abstract

A consideration of the judgement of the International Court of Justice in the North Sea Case in 1969 shows that the outer boundary of a country bordering on the ocean encloses those areas under the sea which constitute a natural prolongation of its land territory. The Geneva Convention of 1958 had defined jurisdiction over the Continental Shelf as bounded by the 200 metre line or beyond that line to the limit of exploitability of natural resources. Recent advances in deep sea mining and drilling have raised fears of a race for submarine claims or of an uncontrolled expansion of national borders to midlines of oceans, unless new conventions or treaties are agreed upon. The equidistance principle applies only as a means of equitable apportioning of shelf areas between nations whose territories adjoin the same shelf.

Where a country faces the ocean, neither distance nor depth or flatness or declivity of the ocean floor can provide a basis for drawing the outer limits of its jurisdiction. On the basis of the principle of natural prolongation and taking into consideration the fact that the crust of the earth under the continents is different from that under the oceans, it is proposed that geophysical measurements together with bathymetry indicative of underlying crustal structure, rather than arbitrary frame lines should be used for the determination of the boundaries between Australia and the deep ocean, with due allowance for possible local complexities.