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Ocean Surface Topography from Space
EDUCATION
"Believe it or Not" Ocean Facts

Powerful Properties | Watching our Waters | Fishy Facts | Astounding Aquatic Animals | Miscellaneous Marine Matters


Earth's ocean is very important to us; it covers almost three-quarters of our planet.

Photo of a glacier.
If all the ice in glaciers and ice sheets melted, the sea level would rise by about 80 meters (262 ft), about the height of a 26-story building.

90% of an iceberg is under water--ships beware!

Ten meters (33 feet) of ocean depth has the same mass as the whole atmosphere; 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.

Photo of the Pacific Ocean.
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 (3,281 ft).

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.


Artists concept of the OSTM/Jason-2 spacecraft.
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 Earth can provide us with information about the entire global ocean in a few days or weeks.It would take ships weeks or months to make the trip around Earth.

Satellite instruments can measure the average height of an ocean patch the size of Pasadena, California. 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.

Since fish find food in zones where cold and warm water mix, fisherman can use satellite data to find areas where fish are most likely to be.


Photo of a fish.
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.

Image of a flounder.
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.


Astounding Aquatic Animals

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.

Image of a whale tail.
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!


Miscellaneous Marine Matters

Photo of a glacier.
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.

Image of Europa, one of Jupiter's moons.
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).



These "fun facts" were compiled by many JPL oceanographers and friends.


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