Three fourths of the Earth is covered by water.
The water is divided into four main oceans, the
Atlantic, Pacific, Arctic and Indian Oceans.
The land under the oceans is like the land above. It has mountain
ranges, ridges, valleys, volcanoes, plains and trenches
You can see the mountain ranges that run
under the oceans.
Surrounding nearly all continents is a shallow extension of the
continent known as the continental shelf. This shelf is relatively
shallow, tens of meters deep compared to the thousands of meters
deep in the open ocean, and extends outward to the continental
slope where the deep ocean truly begins.
The continental slope connects the continental shelf and the
ocean basin.
Deep water is inhospitable for human divers and other animals because
it's cold and dark, and the weight of water overhead exerts intense
pressure. Many animals can withstand the harsh conditions at surprising
depths, but humans need the protection of mechanical divers.
SCUBA Dive 475 ft
Jim Diving Suit Untethered Dive 1968 ft
1969, Grumman Aerospace Corporation's
research submarine Ben Franklin NR-1,
the Navy's nuclear submarine
RMS Titanic's Final Resting Place
DSV Alvin 13,124 feet
Jason (robotic submarine) 19,685 ft
Deepest Recorded Fish 27,460 ft
In 1960, the US Navy sent the Trieste (a
submersible - a mini-submarine designed
to go really deep) down into the depths of
the Marianas trench, 35,813 feet
Research vessel
FLIP, short for Floating Instrument Platform, is a 355-foot (108-meter)
spoon-shaped buoy. As a buoy, or float, FLIP needs another ship to pull it
to a research site. Once in place, FLIP flips. The long tube-like end, or
spoon handle, has special tanks, called ballast tanks. These tanks are
flooded with 700 tons of seawater, causing them to sink. As this end of
FLIP sinks, the other end, kept afloat with air tanks, rises out of the
water. Crew members and scientists, on board while FLIP flips, simply
step up onto the walls as the walls become decks. In just 20 minutes,
FLIP is in a straight up-and-down, or vertical, position, with 300 feet (91
meters) of the ship underwater and 55 feet (17 meters) out of water.
In 1996, H.O.T. completed Deep Flight I (DFI), an experimental, one-person submersible
In December 2002, HOT built and
completed testing the Deep Flight
Aviator, a 2-person winged
submersible purpose-built to fully
explore the concept of underwater
flight
The Marianas Trench
or 'The Challenger Deep'
It's the deepest spot in any ocean of
the world. It is located in the Pacific
Ocean, just east of the Phillippines.
Many strange creatures
live in the perpetual dark
and crushing pressure of
this deep ocean floor
Fish of the deep ocean include some of the most
unusual and least-known fish in the world. Many of
them have large eyes, huge mouths, fanglike teeth,
and light organs that flash on and off in the dark
waters of the depths. Most deep-ocean fish seldom, if
ever, come to the surface.
Driven by forces such as wind, tides and gravity, currents
keep our oceans in constant motion. Currents move large
amounts of water great distances.
The most important driving force behind tides is the
gravitational pull of the moon. Besides the sun and moon,
the shape of the coastline, depth of the water and features
on the ocean floor all affect tides.
HIGH TIDE
LOW TIDE
Everything from earthquakes to ship wakes creates waves;
however, the most common cause is wind. As wind passes over the
water's surface, friction forces it to ripple.
The Great Barrier Reef, the
world's largest coral reef,
extends about 1,400 miles
(2,300 kilometers) along
Australia's northeast coast.
Its approximately 400
species of colorful coral
attract many divers.
Amazing colors and
shapes and thousands
of fishes make coral
reefs one of the most
spectacular underwater
places for people to
visit. Each reef is
completely unique in
its shape and the kinds
of animals that call it
home. A great number
of plants and animals
that live in coral reefs
have not been studied,
or even named, yet.
THE END