The first zone - the underwater suburb of continents. The underwater suburb of continents is the suburb of continents flooded with ocean waters. It in turn consists of the shelf, a continental slope and the continental bottom. The shelf - the coastal ground plain with quite small depths, in effect continuation of suburban plains of sushi. The most part of the shelf has platform structure. On the shelf are frequent residual (reliktova of a form of a relief of a surface origin, and also relic river, glacial deposits. It means that at quarternary otstupaniye of the sea extensive spaces of the shelf turned into the land.
The third - the main - a zone of a bottom of the World Ocean - an ocean bed, it differs in development of crust of exclusively oceanic type. The bed of the ocean occupies more than a half of its area at depths up to 6 km. On a bed of the ocean there are ridges, a plateau, heights which divide it into hollows. Ground deposits are presented by various Ils of an organogenic origin and the red deep-water clay which arose from thin insoluble mineral particles, space dust and volcanic ashes. At the bottom of many ferromanganese concretions with impurity of other metals.
As because of gradual loss of heat the melted subsoil of Earth decreased in volume, there was a horizontal compression of bark which was deformed. There were folded mountain chains, bark subsidence.
Outlines of the World Ocean during the first period of the Palaeozoic Era - cambrian, which age is estimated in nearly 500 million years, were not similar to the modern at all. The Pacific Ocean representing perhaps, a hem on crust, had almost same outlines, as well as now. However other oceans seized the big areas occupied now with the land.
Process of an erosion, or washout started acting on Earth. This process made deep impact on evolution of sushi and sea. Outlines of the seas, and together with them and contours of oceans constantly changed. As a result of an erosion and earth movement the new seas were created, and the bottom of the old rose and turned into the land.
Are specific to the World Ocean and other exogenous processes forming a relief of its bottom. It first of all the work of waves transforming a bottom relief in a coastal zone, activity of the ebb-tide currents forming a specific relief of sandy ridges and carrying sedimentary material. Sedimentary material constants (geostrophicly move, besides, oceanic currents.
In system of sciences about Earth the important place is taken by the oceanology covering all sum of knowledge of the World Ocean and its interrelations with the mainland of Earth and the atmosphere. The modern oceanology relies on achievements of physics, chemistry, biology, geology and itself makes an essential contribution to development of these sciences.
Oceanic ridges are quite accurately divided into two types: svodovo-clumpy and clumpy. Svodovo-glybovye structures represent in a basis the svodovy, linearly extended raisings of oceanic bark usually broken by cross breaks into separate blocks (The Hawaiian spine forming the underwater basis of the same name the archipelago.
Other important feature of termokhalinny circulation is connected with density stratification of the ocean and its influence on hashing. Water density with depth increases in the ocean and lines of constant density go almost horizontally. It is much easier to mix water with different characteristics in the direction of lines of constant density, than across them.
Some distinctions between oceans are connected with distinctions in outlines of their pools. The Atlantic, Indian and Silent oceans have a different form. But some of distinctions are defined by features of a field of a wind, as, for example, in the Indian Ocean. Circulation in the southern part of the Indian Ocean is in the main similar to circulation in the southern basins of the Atlantic and Silent oceans. But in northern part of the ocean Ind7iyskogo it obviously submits to monsoonal winds where in the period of summer and winter monsoons the circulation picture completely changes.
At an ocean floor there are also gravitational processes. Powerful underwater landslides complicate a relief of continental slopes, slopes of underwater ridges and heights. Other factor of a relyefoobrazovaniye - mutyevy streams.