Ocean Enviroment

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Ocean Environment


The sea is the most obvious feature of the earth's surface.
Approximately seventy percent of this surface is covered by water, in one way or
another. Beneath this water are the familiar sands of the beaches, bottoms of
bays, and the inshore ocean. Farther offshore this water covers an amazing
submarine topography of underwater canyons, trenches, mountains, and plains.
Unlike the continents, which are physically separated from one another, the
oceans are continuous and interconnected. Since the "world ocean is
continuous"(M.J. Keen) it has similar characteristics throughout. In the early
1870s oceanographers collected seawater samples from all of the seas of the
world at a variety of depths. When analyzed, the samples were found to have
quite similar characteristics. These findings convinced many that a method of
study was needed. The study of oceans was named oceanography.
Density, salinity, and temperature are very important concepts in the
study of oceanography. The salinity and temperature of the water influence its
density, and the differences in density are the major factor in understanding
the formation of currents and the positions of water masses in the sea. In
addition, temperature and salinity play major roles in influencing the
distribution of plants and animals.
The sediments of the sea floor may be divided into lithogenous,
hydrogenous, biogenous, and cosmogenous sediments. Lithogenous sediments are
the major sediments on the ocean floor. They are derived from the chemical and
mechanical weathering of rocks. Biogenous sediments are composed primarily of
the protective outter covering of small marine animals and plants. If these
remains comprise at least thirty percent of the sediment it is called an "ooze".
"Oozes" were named for the types of organisms that formed them. Hydrogenous
sediments form as a result of the chemical reactions that occur in the seawater....