TOPOGRAPHY OF THE OCEAN FLOOR, WHAT IS CONTINENTAL SHELF? - Coggle Diagram
TOPOGRAPHY OF THE OCEAN FLOOR
We examined the topography of the sea floor from the perspective of plate tectonics, but here we are going to take another look at the important features from an oceanographic perspective. The topography of the northern Atlantic Ocean is shown. The important features are the extensive continental shelves less than 250 m deep (pink); the vast deep ocean plains between 4,000 and 6,000 m deep (light and dark blue); the mid-Atlantic ridge, in many areas shallower than 3,000 m; and the deep ocean trench north of Puerto Rico (8,600 m)
CONTINENTAL SLOPE & SUBMARINE CANYONS
Continental slope marks the boundary of the continental granitic mass and defines the boundary between continental crust and oceanic crust.
An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3,000 and 6,000 metres
are prominent, long, narrow topographic depressions of the ocean floor.
The deepest of all is the Marianas Trench with 11,000 m
Other trenches can go over 10,000 m deep; the Japan Trench is over 9,000 m deep; and the Puerto Rico and Chile-Peru Trenches are over 8,000 m deep.
SEAMOUNTS OR GUYOTS
Seamounts and Guyots are some more unique features of the ocean basins. Seamounts are isolated steep sided submarine volcanic mounts.They may be 2-100 km wide and < 1 km high above the sea floor.
Guyots are flat-topped seamounts. The flat-top is created due to wave action. It is named after the Swiss scientist. A.H. Guyot.
Now-a-days, Digital Terrain Models of Seamounts are generated from multibeam sonar data. These methods are in a position to provide threedimensional pictures of the ocean floors and morphology.
WHAT IS CONTINENTAL SHELF?
The inner and outer continental shelf. It is about 70 km wide, bordering the continent topography. It generally resembles that of the coastal plain. It has a gentle slope of about 0.1 degree.
Sediments are transported across this shelf region by the currents.The continental slope is rather steep slope with 4 degrees following the continental shelf break.