Oceans are very important to us; they cover almost three-quarters of
the Earth.
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If all the ice in glaciers and ice sheets melted, the sea level would
rise by about 80 meters, about the height of a 26-story building.
90% of an iceberg is under water--ships beware!
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Ten meters (33 feet) of ocean depth has the same mass as the whole atmospher;
2.5 meters (8 feet) of ocean depth holds as much heat as the whole atmosphere;
2.5 centimeters (1 inch) of the ocean depth has as much water as the whole
atmosphere.
Average January temperatures in Seattle are warmer than Kansas City,
or even Oklahoma City, even though both are much further south! In the
winter, the ocean near Seattle acts like a large radiator, slowly releasing
heat stored up in previous months.
If sea level should rise by 3 meters (10 feet), many of the World's
coastal cities, like Venice, London, New Orleans, and New York, would be
under water.
Tsunamis are caused by offshore earthquakes and travel at about 800
kilometers (500 miles) per hour. At sea, they are hard to "see" because
they're no more than 10 centimeters (4 inches) high! As they come toward
the shore, tsunamis build up many tens of meters high, and can wash inland
more than a kilometer.
The ocean surface has big valleys in it! Over deep ocean canyons the sea
surface dips because of the local gravity, leaving depressions as deep
as 20 meters (65 feet) and as wide as 160 kilometers (100 miles).
Although tap water freezes at 0 degrees Celsius (32 degrees Fahrenheit),
seawater does not freeze until about minus 2 degrees Celsius because 3%
of it is salt. This is why New Englanders "salt the roads" after heavy
snows.
Instruments on satellites in space, hundreds of kilometers above us can
measure many things about the sea: surface winds, sea surface temperature,
water color, wave height, and height of the ocean surface.
Satellites orbiting the Earth can provide us with information about
all of the oceans over the span of days or weeks, but it takes ships weeks
or months to go around the Earth.
Satellite instruments can measure the average height of an ocean patch
the size of Pasadena, 8 kilometers--5 miles wide, to within 2.5 centimeters--1
inch.
Satellite infrared instruments can measure the temperature of the surface
of a patch of ocean about a kilometer (1/2 mile) square to much less than
1/2 degree Celsius. The same technology is used in police helicopters,
which carry an infrared sensor, to find suspects hiding in the bushes:
people are warm; plants, cold.
Data from satellite instruments are used by fishermen to find areas
where fish are most likely to be found. Fish find food in zones where cold
and warm water mix.
In the last 100 years, humans have perfected fish-finding electronics,
but fish have not developed human-avoidance skills to match.
About 14% of the world's protein consumption comes from fish.
Some fish in cold Antarctic waters have natural antifreeze in their
blood so they don't freeze.
Flatfish (halibut, flounder, turbot, and sole) hatch like any other "normal"
fish, but as they grow, they turn sideways and one eye moves around so
they have two eyes on the side that faces up. Flatfish taste pretty yummy,
too!
If a flounder lies on an underwater checkerboard, it will try to camouflage
itself by developing "checkered" black and white markings.
Albatross drink seawater--they only come ashore to lay their eggs and
raise their young.
Coral is a colony of tiny animals that have porous limestone skeletons
which can be used for bone repair in humans.
Coral reefs are home to about 10% of all the fish that people eat.
Coral reefs cover about one-fiftieth of the ocean floor, but about one-quarter
of all marine species make reefs their home.
Corals produce a natural sunscreen which chemists are trying to extract
for use by humans--watch for it in the next few years!
Many abyssal creatures (those who live at the bottom of the ocean) glow
in the dark, like fireflies.
The largest recorded specimen of the blue whale is 33 meters (110 feet)
long--about the height of an 11-story building.
Manatees, which are large, gentle, fat marine mammals, were mistaken
for mermaids by some explorers--perhaps those explorers needed glasses!
The ocean is deeper than Mount Everest, at 8,850 meters (29,000 feet),
is tall. In 1960 the U.S. Navy, using Auguste Piccard's bathyscaph
"Trieste," reached the bottom of the Marianas Trench, 10,900 meters (35,800
feet) down.
At that depth, the temperature is always just above freezing, the pressure
is more than 1000 times what it is on the surface, and many bottom-dwelling
fish and invertebrates call it home!
Under the ocean, you can find many mountain ranges.
One large Antarctic iceberg could supply all of Los Angeles' water supply
for 5 years!
Question: Who "cooked up" the most accurate navigational charts of the
18th century?
[Answer: Captain James Cook]
If you were an alien landing on Earth, you would have about a 60% chance
of landing out of sight of land.
You float better in the Mediterranean Sea than in the waters off Santa
Monica because the Mediterranean is saltier and denser.
Seven million years ago, when geological forces lifted the Straits of
Gibraltar and blocked the flow of Atlantic Ocean water into the Mediterranean,
the Mediterranean Basin was completely dry! And in some places its bed
lies 4,000 meters (13,000 feet) below sea level. When the Straits
of Gibraltar dropped to today's level, what may have been the Earth's grandest
waterfall may have run for 1,000 years, until the sea was full.
Europa, a moon of Jupiter just a bit smaller than our Earth's moon, may
have a world-wide ocean 100 kilometers (60 miles) deep covered with ice.
Such an ocean might contain more liquid water than all the Earth's oceans
combined!
The Great Barrier Reef off the eastern coast of Australia can be seen
from the moon!
Dissolved gold is found in the water of all oceans (a very small
amount, of course, but it is still there).
