Glossary
- The Area
- Baselines
- Bathymetric survey
- “Broad-margin”
- Continental shelf
- Continental Margin
- Continental Slope
- Deep Seabed
- Extended Continental Shelf
- The Exclusive Economic Zone (EEZ)
- Gardiner Line
- High Seas
- Nautical Mile
- Seafloor Rise
- Seismic survey
- Territorial Sea
- United Nations Convention on the Law of the Sea
The Area
is the deep ocean floor not subject to sovereign rights of coastal states, which is the “common heritage of mankind.” Jurisdiction over the seabed of the Area is exercised by the International Seabed Authority, created under Part XI of UNCLOS. According to Article 137 of UNCLOS, “no State shall claim or exercise sovereignty or sovereign rights over any part of the Area or its resources, nor shall any State or natural or juridical person appropriate any part thereof. No such claim or exercise of sovereignty or sovereign rights nor such appropriation shall be recognized”.
Baselines
constitute the line from which the breadth of the territorial sea is measured. The normal baseline is the low-water line. Where a coast, such as Canada's, is deeply indented, straight baselines joining appropriate points may be drawn.
Bathymetric survey
is the hydrographic survey that measures the depth of the water and determines the shape of the seabed.
“Broad-margin”
state is a coastal state with continental margin extending beyond 200 nautical miles from the baselines.
Continental shelf
comprises “the seabed and subsoil of the submarine areas that extend beyond its territorial sea throughout the natural extension of its land territory to the outer edge of the continental margin, or to a distance of 200 nautical miles 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.” (see article 76.1 of UNCLOS).
Continental Margin
is the area between the shoreline and the deep seabed consisting of the continental shelf, slope, and rise.
The continental slope
is "the outer portion of the continental margin that extends from the shelf edge to the upper part of the rise or to the deep ocean floor where a rise is not developed". This definition is from the Scientific and Technical Guidelines of the Commission on the Limits of the Continental Shelf.
Deep Seabed
is the ocean floor beyond the continental margin.
Extended Continental Shelf
is the continental margin beyond 200 nautical miles.
The Exclusive Economic Zone (EEZ)
is an area beyond and adjacent to the territorial sea extending up to 200 nautical miles from the baselines. The rights and duties of states within the EEZ are set out in articles 55-75 of UNCLOS.
Gardiner Line
is a method for determining the outer limit of the continental shelf by connecting points established using the sediment formula. This formula was originally proposed by Mr. Gardiner of Ireland and is reflected in Article 76 of UNCLOS. An outer limit point can be established at the point where the depth of sediment is 1% of the distance to the foot of the slope, provided that there is continuous sediment between this point and the foot of the slope point.
High Seas
refer to area of the sea beyond the national jurisdiction of any state.
Nautical Mile
: 1 nautical mile equals 1.852 km
The seafloor rise
is a "wedge-shaped sedimentary body having a smaller gradient than the continental slope". This definition is from the Scientific and Technical Guidelines of the Commission on the Limits of the Continental Shelf.
Seismic survey
is a survey of the seabed using sound waves that are reflected from different layers of material in the subsoil. Echoes from each layer are detected by receivers, and the travel time and speed of sound in different materials determine the characteristics of the subsoil and the depth of sedimentary material.
Territorial Sea
comprises an area of the sea not exceeding 12 nautical miles from the baselines where the coastal state exercises sovereignty, subject only to the right of innocent passage.
The United Nations Convention on the Law of the Sea
establishes a legal framework for the oceans by creating maritime zones like the territorial sea, the exclusive economic zone and the continental shelf. The Convention also sets out provisions governing oceans activities as diverse as navigation, fisheries, marine scientific research and protection of the marine environment. Article 76 of the Convention provides the legal basis and mechanism by which states, like Canada, with a continental shelf which extends beyond 200 nautical miles can delineate its outer edge.
