Sea

The sea, connected as the world ocean or simply the ocean, is the body of salty water that covers approximately 71 percent of the Earth's surface. The word sea is also used to denote second-order sections of the sea, such as the Mediterranean Sea, as well as certain large, entirely landlocked, saltwater lakes, such as the Caspian Sea. The sea moderates Earth's climate and has important roles in the water cycle, carbon cycle, and nitrogen cycle. Humans harnessing and studying the sea have been recorded since ancient times, and evidenced well into prehistory, while its modern scientific study is called oceanography. The most abundant solid dissolved in seawater is sodium chloride. The water also contains salts of magnesium, calcium, potassium, and mercury, amongst many other elements, some in minute concentrations.

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New Species of Symbiotic Sea Anemone Discovered Off Coast of Japan

Sea Turtles Escape Tiger Sharks By... Not Moving

Indigenous communities used the Caribbean Sea as an aquatic highway

Swarm of rainbow-colored starfish devour sea lion corpse on seafloor

Hubble Space Telescope 'sea of sequins' image shows off a star cluster

Hubble Space Telescope 'sea of sequins' image shows off a star cluster

Melting ice could open up an Arctic Sea route not controlled by Russia

Researchers discover 'hotspots' of three-layered alternatively rotating circulation in South China Sea

These Polar Bears in Greenland Can Survive With Less Sea Ice

Some polar bears in Greenland survive on surprisingly little sea ice

Newly identified population of polar bears survives on glacier slush, not sea ice

Russian Cosmonaut Shares Unique Video of Shrinking Aral Sea as Seen From Outer Space (Video)

Rural areas near coast will bear the brunt of U.S. sea-level rise

Deep-Sea Pipelines Harbor Biodiversity, but Also Collect Plastic

Mice of the sea: Watch elephant seals use whiskers to find food

Researchers reveal add-on benefits of natural defenses against sea-level rise

Millions of Shipwrecks Lost to The Ocean Are Changing Life in The Deep Sea

SpaceX launches Egyptian communications satellite, lands rocket on ship at sea

See the Mysterious Sea Creatures That Only Come Up at Night

Is the Red Sea really red?