As used in UNCLOS Article 76, “foot of the continental slope” means the point where the continental slope meets the continental rise or, if there is no rise, the deep ocean floor.
Comment
In LOAC-governed situations under the “other rules of international law” clauses in UNCLOS, a different definition may apply. The same may be the situation if the UN Charter supersedes UNCLOS or if jus cogens norms apply.
Consolidated Glossary ¶ 36 now quotes UNCLOS Article 76(4)(b) and defines “foot of the continental slope” as “In the absence of evidence to the contrary, the foot of the continental slope shall be determined as the point of maximum change of gradient at its base.” The Glossary adds:
It is the point where the continental slope meets the continental rise or, if there is no rise, the deep ocean floor. To determine the maximum change of gradient requires adequate bathymetry covering the slope and a reasonable extent of the rise, from which a series of profiles may be drawn and the point of maximum change of gradient located.
Former Consolidated Glossary ¶ 34 recited UNCLOS Article 76(4)(b) and says the continental slope “is the point where the continental slope meets the continental rise or, if there is no rise, the deep ocean floor,” adding the same quoted material.
UNCLOS Articles 76(4)(a)(i) and 76(4)(a)(ii) use the continental slope as a point of reference for the continental margin. Article 76(4) (b) says that absent contrary evidence, “the foot of the continental slope shall be determined as the point of maximum change in the gradient at its base.”
