Distributions of oceans and ocean currents
Distribution and Importance of Oceans:
Oceans cover about 70% on the earth’s surface
Great importance to humans in number of ways, include: regulating global climates and as a source of economic materials.
Oceans are also important for leisure and recreation
Oceans cover about 50% of the earth’s surface in the northern hemisphere and about 90% in the Southern hemisphere
Ocean / Sea
Area in 1000km^2
Pacific Ocean
166 229
Atlantic Ocean
86 551
Indian Ocean
73 442
Arctic Ocean
13 223
South China Sea
2957
Caribbean Sea
2516
Mediterranean Sea
2509
Distribution of Ocean Currents:
Warm ocean currents move water away from the equator, whereas cold ocean currents move water away from cold regions towards the equator
The major currents move huge masses of water over long distances
The warm Gulf Stream, transport 55 million m^3 per second
Without it, the “temperate” lands of north-western Europe would be more like the sub-Arctic
The cold Peru Current and the Benguela Current of south-west Africa bring in nutrient- rich waters dragged to the surface by offshore winds
Great Ocean Conveyor Belt – deep, grand-scale circulation of the ocean’s waters effectively transfers heat from the tropics to colder regions, such as northern Europe
Ocean Morphology
Features of the Ocean Floor:
The ocean floor consists of man features such as deep-sea trenches, mid- ocean ridges, transform faults, rift valleys, deep abyssal plains, continental slopes and continental shelves. Smaller features include submarine canyons and submarine volcanoes or seamounts.
Seamounts – are extinct volcanic cones that lie below the surface. A guyot is a flat- topped volcano that once reached the surface but later subsided
Abyssal Plain – is at the edge of the continental slope. These plains cover large areas of the sea floor at depths of between 4000 and 6000 m. They are generally flat and