 |
How much of the Earth’s
surface does the ocean cover? |
 |
The ocean covers more than 70%
of the Earth’s surface. That’s why Earth is often
called the “water planet.” |
|
 |
How deep is
the ocean? |
 |
The deepest known point on Earth is
at the bottom of the Mariana Trench, a depression in the floor of
the western Pacific Ocean, just east of the Mariana Islands. This
trench is 1,554 miles long and 44 miles wide. Near its southwestern
extremity, 210 miles southwest of Guam, lies the deepest point on
Earth. This point — referred to as the Challenger Deep —
plunges to a depth of nearly 7 miles. In 1960,
the Trieste, a manned submersible owned by the U.S. Navy, descended
to the bottom of the Mariana Trench. There, the pressure from the
weight of the vast ocean above is tremendous. At more than
8 tons per square inch, it’s the equivalent of an average-sized
woman trying to hold 48 jumbo jets! |
|
How
“hot” is the hottest animal on Earth? |
|
University of Delaware marine scientist Craig Cary and his
colleagues discovered that an inhabitant of the deep sea is
the most heat-tolerant animal on Earth. The
Pompeii worm (Alvinella pompejana) can survive
an environment as hot as 80° C (176°F) — nearly
hot enough to boil water. How it can withstand this tremendous
heat is a mystery that Dr. Cary and his team are working to
solve.
While some bacteria can live at even higher temperatures
than the Pompeii worm, Dr. Cary says the Pompeii worm ranks
as the most heat-tolerant creature among higher-order life
forms. It beat out the Sahara Desert ant, which formerly held
the record at 55°C (131°F).
|
|
|
The
water erupting from hydrothermal vents is hotter than 100°C (212°F),
yet it does not boil. Why? |
|
As vent water bursts out into the ocean,
its temperature may be as high as 400°C (750°F). Yet this
water does not boil because it is under so much pressure from the
tremendous weight of the ocean above. When the pressure on a liquid
is increased, its boiling point goes up. |
|
When
was the first submarine built? |
|
Cornelius van Drebel, a Dutch inventor, is usually credited
with building the first submarine. His underwater vessel consisted
of a wooden frame sheathed in leather. Oars extending out
the sides propelled the craft through the water, at depths
up to 4.6 meters (15 ft). The oar openings were sealed with
tight-fitting leather flaps. Drebel tested the sub in the
Thames River in England between 1620 and 1624. King James
I is said to have taken a short ride in the craft.
|
|
|
When
you see R/V before the ship name Atlantis, what do you think
it means? |
|
The R/V is the abbreviation
for research vessel. Now, here’s another question: what do you
think the abbreviation F/V stands for? Or how about HMS in HMS Titanic? |
|
What
mountain range is the East Pacific Rise a part of? |
|
The Earth’s longest mountain range is underwater. Over
56,000 kilometers (35,000 mi) long, this mountain range, called
the Mid-Ocean Ridge system, winds around the globe. The East
Pacific Rise is a portion of this massive ridge system. The
East Pacific Rise occurs in a geologically active area where
tectonic plates are moving apart, and new seafloor is being
born.
|
|
|
How
long does a typical dive last aboard the submersible Alvin? |
|
An average dive lasts for eight
hours. It takes about an hour per mile to descend and the same amount
of time to return to the surface. The crew generally works for four
to five hours on the seafloor before calling it a day. Alvin
can accommodate two scientific observers in addition to the pilot.
It’s very cramped in the sub and very cold. At over a mile down,
the water outside the sub is only a few degrees above freezing. |
|
The
right side of a ship, looking forward, is the starboard side.
True or False? |
|
True. Now, can you tell us where the port side is, and how
about the bow and the stern?
|
|
|
