Steven R. Van Hook
seas of Earth
wrap more than 2/3 of the planet. The Pacific Ocean alone
half of the globe and is bigger than all the world's landmasses
Yet for all its pervasive
presence, we have better maps of the surface of Mars than we do of the
– in his marvelous
book, A Short History of Nearly Everything
shares some other
insights into the wonders of the deep:
The Pacific holds
51.6 percent of the planet's ocean waters; the Atlantic holds 23.6 percent; the Indian Ocean
another 21.2 percent; and scattered seas hold the remaining 3.6 percent.
Ninety-seven percent of
all our water is in the seas, and of the 3 percent of Earth's water
that is fresh, most of that exists in the ice sheets of Antarctica.
Only 0.036 percent of
drinkable water is found in lakes, rivers, and reservoirs, and a mere
0.001 percent of fresh water is in clouds and vapor.
There are 320-million
cubic miles of water on our world, and in our closed planetary system,
that is all we're ever going to get. The water we drink now has been
circulating billions of years since the Earth was an infant.
The average depth of the
ocean is 2.4 miles, and some 60 percent of planet's surface is covered
by seas more than a mile deep.
The Pacific Ocean is about
18 inches higher on its western edge, a result of the Earth's spin and
According to estimates,
there may be as many as 30-million animal species living in the ocean,
most of those yet undiscovered.
However, less than 10
percent of the ocean is considered 'naturally productive,' as most sea
species prefer to live in shallower waters with warmth and light.
Coral reefs only take up only 1 percent of ocean space, yet 25% of sea
fish make their homes there.
A liter of sea water
contains 2.5 teaspoons of salt, and though our bodies harbor a similar
ratio of salt-to-water, drinking sea water will overwhelm our systems
with salt and shut down our kidneys.
There is enough salt in
the sea to bury the entire dry landmass to a depth of 500 feet.
The speed of sound in
water is about 4,500 feet per second
– five times faster than sound's
speed through air. This is what helps whales to communicate across
hundreds of miles (factoid courtesy of History Channel's Modern
Still, for all the talk of
our blue-planet-water-world, only 0.06 percent of Earth's mass is
water. We're still a very dry place.
Bryson shares other
well-researched facts with wit and flair
– including disturbing stories
of depleted species and horrific dumping of radioactive wastes.
Bryson's book, A Short History of Everything, as well as his
– including In A Sunburned Country, A Walk in
the Woods, and I'm a Stranger Here Myself
– are available on
Amazon.com and other
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