continental margin
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continental margin zone separating the emergent continents from the deep-sea
floor. Where a continental margin results from a process of rifting and seafloor spreading (~plate tectonics) it is broad and gentle. Such margins are
abandoned divergent plate boundaries and are called passive continental margins;
there is only limited tectonic activity. Examples of this type are the margins
bordering the North Atlantic Ocean. An active continental margin contains a
convergent plate boundary; it forms the leading edge of the overriding plate
and parallels oceanic trenches. These narrow, steep-bounded margins are
sites of intense earthquake activity with a volcanic arc on the continental
side. The west coast of South America is a typical example.
continental rise ~sea-f1oor topography.
continental shelf submerged edge of the continents, ~shelf sea.
continental slope the relative steep slope from the offshore border of the continental shelf (~shelf sea) to the rise from the abyssal plain. ~deep-sea benthos and
sea-floor topography.
continuity equation one of the basic equations in hydrodynamics, formulating the
condition of conservation of mass in a moving fluid.
Continuous Plankton Recorder (CPR), or Hardy Plankton Recorder. A plankton sampler in 1925 invented by A.C. Hardy designed for towing behind commercial
vessels, preserving the catch between two gauzes which are slowly wound
together on a take-up spool enclosed in a formalin reservoir. The spool is
driven by the outside water flow, turning a propellor at the back of the
recorder. Operating routinely in the North Sea since 1932, and in the North
Atlantic since 1948, the CPR catches form the best time series of plankton
available. The Longhurst-Hardy Plankton Recorder is a version with electronically operated power pack and temperature-depth registration, to obtain discrete samples for tens of strata in one double oblique tow. ~zooplankton samplers, ~Discovery Expeditions (2).
contour current bottom current along bathymetric contours. The routes of flow of
cold, dense water are mostly governed by the interaction of the sea-floor topography and the forces produced by the rotation of the earth. This Coriolis force
pushes the currents towards the boundaries of the basins through which
they flow, guiding currents along bathymetric contours. ~contourite.
contourite deposited by isobathic flows or contour currents. Contourites consist of a
sequence of thin beds with sharp contacts, are persistently laminated and
well sorted and graded. They are usually found in sediments of the continental slope.
70
continental margin zone separating the emergent continents from the deep-sea
floor. Where a continental margin results from a process of rifting and seafloor spreading (~plate tectonics) it is broad and gentle. Such margins are
abandoned divergent plate boundaries and are called passive continental margins;
there is only limited tectonic activity. Examples of this type are the margins
bordering the North Atlantic Ocean. An active continental margin contains a
convergent plate boundary; it forms the leading edge of the overriding plate
and parallels oceanic trenches. These narrow, steep-bounded margins are
sites of intense earthquake activity with a volcanic arc on the continental
side. The west coast of South America is a typical example.
continental rise ~sea-f1oor topography.
continental shelf submerged edge of the continents, ~shelf sea.
continental slope the relative steep slope from the offshore border of the continental shelf (~shelf sea) to the rise from the abyssal plain. ~deep-sea benthos and
sea-floor topography.
continuity equation one of the basic equations in hydrodynamics, formulating the
condition of conservation of mass in a moving fluid.
Continuous Plankton Recorder (CPR), or Hardy Plankton Recorder. A plankton sampler in 1925 invented by A.C. Hardy designed for towing behind commercial
vessels, preserving the catch between two gauzes which are slowly wound
together on a take-up spool enclosed in a formalin reservoir. The spool is
driven by the outside water flow, turning a propellor at the back of the
recorder. Operating routinely in the North Sea since 1932, and in the North
Atlantic since 1948, the CPR catches form the best time series of plankton
available. The Longhurst-Hardy Plankton Recorder is a version with electronically operated power pack and temperature-depth registration, to obtain discrete samples for tens of strata in one double oblique tow. ~zooplankton samplers, ~Discovery Expeditions (2).
contour current bottom current along bathymetric contours. The routes of flow of
cold, dense water are mostly governed by the interaction of the sea-floor topography and the forces produced by the rotation of the earth. This Coriolis force
pushes the currents towards the boundaries of the basins through which
they flow, guiding currents along bathymetric contours. ~contourite.
contourite deposited by isobathic flows or contour currents. Contourites consist of a
sequence of thin beds with sharp contacts, are persistently laminated and
well sorted and graded. They are usually found in sediments of the continental slope.