Facts About Our Oceans

Our Blue Planet : Nearly 71% of the Earth’s surface is ocean and sea. That is an enormous area of about 140 million square miles (362 million sq km).

Ocean Life : In addition to all of the sea mammals, amphibians, fish and countless species of fish and marine plants, a single swallow of seawater may contain millions of bacterial cells, hundreds of thousands of phytoplankton and tens of thousands of zooplankton.

Depth : Challenger Deep in the Mariana Trench is the deepest point in Earth’s oceans. The bottom there is 10,924 meters (35,840 feet) below sea level.  If  Mount Everest, the highest mountain on Earth, were placed at this location it would be covered by over one mile of water. The Challenger Deep is named after the British survey ship Challenger II, which discovered this deepest location in 1951.

The Mariana Trench in the western Pacific and is 3 times the average depth of 12,200 feet (3,720 m).

Reefs : The Great Barrier Reef, measuring 1,243 miles, is the largest living structure on Earth. It can be seen from the Moon.
Coral reefs make less than 0.5 per cent of the ocean floor and yet it is estimated that more than 90 per cent of marine species are directly or indirectly dependent on them.

Underwater Canyons : The largest canyon in the ocean is Zhemchug Canyon, a giant underwater canyon located in the middle of the Bering Sea. . The canyon has a vertical relief of 2600 meters dropping from the shallow shelf the Bering Sea to the depths of the Aleutian Basin. Zhemchug Canyon is deeper than the Grand Canyon in the United States.

What makes the Zhemchug Canyon the largest canyon in the world is not only its great depth, but its large cross-sectional area. Zhemchug Canyon is the largest submarine canyon in the world, based on drainage area (11,350 km²) and volume (5800 km³).

Ocean Mountains : The ocean ridges form a great mountain range, almost 40,000 miles (64,000 km) long. That  is the largest single feature on Earth. It is one global ridge system forming the longest mountain range in the world and reaches through all the major oceans.

Everybody knows Mount Everest as Earth’s Highest Mountain, that is to say it is the mountain that reaches highest into the skies, or has the highest altitude. But did you know that there is a taller mountain that Mount Everest? Mauna Kea, in Hawaii, rises from the ocean floor forming an island and is over 10,000 meters tall compared to 8,848 meters for Mount Everest – making it the world’s tallest mountain, but it rises only 13,680 feet (4,170 m) above sea level.

Volcanoes : 90% of all volcanic activity on Earth occurs in the ocean. Most volcanoes are found along a belt, called the “Ring of Fire” that encircles the Pacific Ocean. The largest known concentration of active volcanoes on the sea floor is located in the South Pacific where there are around 1,133.

Size : The Arctic Ocean is the smallest ocean, holding only one percent of the Earth’s seawater. This is still more than 25 times as much water as all rivers and fresh water lakes.

The Pacific Ocean  is the largest ocean at 165.2 million square kilometres (63.8 million miles). It extends from the Artic in the north to the Southern Ocean (or, depending on definition, to Antartica) in the south, bounded by Asia and Australia  in the west, and the Americas in the east.

Ice :  Sea ice is frozen sea water that forms in the Arctic Ocean in the Northern Hemisphere, and in the Southern Ocean surrounding Antarctica in the Southern Hemisphere. It forms, grows, and melts in the ocean.

Icebergs, glaciers, and ice shelves float in the ocean but originate on land. Sea ice is highly seasonal, covering, at the maximum, about 19 million sq. km around the Antarctic, which is nearly twice the size of the United States.

The formation of sea ice each year plays a major role in the global climate system and helps to redistribute heat between the equator and the Polar Regions.

10% of the Earth’s surface is covered with ice and Antarctica has as much ice as the Atlantic Ocean has water.

The freezing point of sea water depends on its salt content. Typical ocean water has about 35 grams of salt per litre and freezes at -19ºC .

The average thickness of the Arctic ice sheet is about 9 to 10 feet, although there are some areas as thick as 65 feet.

The Arctic produces 10,000 to 50,000 icebergs annually. The amount produced in the Antarctic regions is inestimable. Icebergs normally have a four-year life-span; they begin entering shipping lanes after about three years.

Temperature :Almost all of the deep ocean temperatures are only a little warmer than freezing (39°F).
However, under the enormous pressures of the deep ocean, sea water can reach very high temperatures without boiling. A water temperature of 400ºC   has been measured at one hydrothermal vent.

Weight : Water pressure at the deepest point in the ocean is more than 8 tons per square inch, the equivalent of one person trying to hold 50 jumbo jets or 8 locomotives.

Currents : The Gulf Stream off the Atlantic seaboard flows at a speed nearly 300 times faster than the normal flow of the Amazon River, the world’s largest river.

Coastlines : The total length of the worlds coastline is greater that the distance from the Earth to the Moon.

Sea Levels : The sea level has risen with an average of 4-10 inches (10 to 25 cm) over the past 100 years and scientists expect this rate to increase. Sea levels will continue rising even if the climate has stabilized, because the ocean reacts slowly to changes.
10,000 years ago the ocean level was about 330 ft (110 mtr) lower than it is now.

If the entire world’s ice melted, the oceans would rise and 85 to 90% of the Earth’s surface would be covered with water as compared to the current 71%.

Density :The density of ocean water varies. It becomes more dense as it becomes colder, right down to its freezing point of -1.9 degrees C. (This is unlike fresh water, which is most dense at 4 degrees C, well above its freezing point.)

Salt : If the salt in the ocean could be removed and spread evenly over the Earth’s land surface it would form a layer more than 500 feet (166 m) thick, about the height of a 40-story office building.

Gold : The world’s oceans contain nearly 20 million tons of gold. If all the gold suspended in the world’s seawater were mined, each person on Earth could have about 9 pounds of gold.

New Life : Scientists have discovered a new form of life, based on chemical energy rather than light energy, which resides in deep-sea hydrothermal vents along mid-ocean ridges.