SEAS & OCEANS
The "seven seas"
is a figurative term meaning all the waters of the earth. The expression first
appeared in ancient literature.
One vast ocean covers the
face of the earth and it is called the "world ocean." All the
so-called "oceans" on maps and globes are really only parts of the
world ocean. The continents of the earth - North and South America, Europe,
Asia, Africa, Antarctica, and Australia - are all but islands in this one huge
body of water.
The parts of the world ocean
cut by points of land or by islands are called seas.
The largest ocean on earth
is the Pacific and is about 63,800,000 square miles in area.
If the earth were smooth,
all the land areas would be covered by seawater to a depth of some 8,810 feet -
or one and two-thirds miles.
"Sea level" of
earth's oceans varies in elevation by as much as 600 feet.
The point halfway between
average high tide and average low tide is called sea level.
percent of the earth's oceans are more than two miles deep, but the average
depth of the Atlantic is 12,500 feet. A mile down, the weight of the water above
that level exerts pressure of one ton per square inch, and temperatures hover
between 30 and 39 degrees Fahrenheit.
every day, along most of the coasts of the world, waters of the ocean rise and
fall, producing the tides. The incoming tide is called the "flood" and
the outgoing, the "ebb."
in sea levels can be produced by ice ages. Extreme glaciation could drop the sea
level by 300 feet, leaving many seaports high and dry. If all the polar ice
melted, the seas could rise as much as 300 feet, covering Florida and other
area of the earth covered by the sea is estimated to be 139,670,000 square
miles. This represents 70.92% of the total surface.
volume of Earth's oceans is estimated to be 308,400,000 cubic miles.
The deepest part of the
ocean yet discovered is in the Mariana’s Trench in the Pacific Ocean. A pound
ball of steel dropped into the water above the trench would take nearly 63
minutes to reach the sea bed 6.85 miles below. The average depth is 14,000 feet.
The Atlantic Ocean has the
largest range of mountains on earth. It winds from the Artic to the Antarctic
with peaks averaging 10,000 feet in height and extends 10,000 miles in length.
There are 4,037,000,000 tons
of oxygen in a cubic mile of sea water.
There are 38 pounds of gold
in a cubic mile of sea water.
There are 128,000,000 tons of salt in a cubic mile of sea water.