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.
These reactions result in the formation of small particles, which are deposited
on the sea floor. Currents move these particles and cause them to collide with
the other particles. If many of these collisions occur they may form nodules.
Nodules are found on some portions of the deep-sea floor. The sediment type
frequently determines the type of organisms that will be found in that specific
area.
"Waves are variable and transitory features of the sea\'s surface."
(Sandra Smith) All waves, from the smallest ripple to the most destructive
tsunami, have common characteristics. They all have crests, troughs, wave
heights, lengths, and periods. Also, water particles that make up the waves all
move in identical orbital patterns. The orbital pattern is up and forward in
the crest and down and back in the trough. It is only when the wave becomes
unstable that the orbital motion is destroyed. The water particles then begin
to move at the same speed as the moving wave form.
Breaking waves release a tremendous amount of stored energy on a beach
face. This energy moves the sand about and changes the configuration of the
bottom. As the bottom configuration is changed by the waves, it changes the
characteristics of incoming waves. This interaction between the waves and the
bottom results in the beach face having an everlasting wave pattern.
Everything in the universe is composed of extremely small paritcles
called atoms, which are often bonded together to form molecules. Molecules are
formed as the result fo the transfer of electrons between atoms. The complete
loss and gain of electrons results in the formation of ionic molecules, which
have completely positive and negative vegions. Unequal sharing of electrons, on
the other hand, characterizes the polar covalent molecules, which have only
partially positive and negative regions. The equal sharing of electrons result
in the formation of nonpolar covalent molecules, which do not develop charged
regions.
Due to the development of charges on ionic and polar molecules,
intermolecular attractive forces form between these molecules, intermolecular
attractive forces form between these molecules and enable the compounds to exist
in the solid and liquid state. Ionic compounds have long-range order and exist
as solids. Polar covalent molecules are liquids because of their short-range
order, while the nonpolar gases do not develop intermolecular attractions and as
a result exibit no order.
Changes in state are due to a change in the order of compounds. When
energy is added, molecular motion increases and intermolecular attractive forces
are disrupted. This results in the melting of solidsand the evaporation of
liquids. When energy is removed, the molecular motion is decreased, which
increases the formation of intermolecular attractive forces. This allows vapors
to condense as liquids to freeze.
The physical and chemical components of water interact with and affect
the plant and animal life in the sea. The plants, animals, and bacteria that
inhabit a given marine area continually react with, change,