The sea in a general sense refers to the ocean or world ocean, the body of salty water that covers approximately 71% of the Earth's surface. Used in a particular sense the word sea refers to particular seas either as second-order sections of the ocean, such as the Mediterranean Sea, or 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, carbon, and nitrogen cycles. 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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Chinese surveillance balloon shot down by US fighter jet over sea

Jurassic Sea Crocodile Fossil Found in United Kingdom

New Species of Giant Sea Scorpion Unearthed in New Mexico

Current Climate: Sea Level Rise Will Lead To Faster-Than-Expected Flooding On The Coasts

Sea spiders can regrow their anuses, scientists discover

Sea spiders can regrow body parts, not just limbs

Immense diversity and interdependence in high temp deep-sea microorganism communities

Wolves eliminate deer on Alaskan Island then quickly shift to eating sea otters, research finds

Some young sea spiders can regrow their rear ends

Wolves are eating sea otters after depleting an Alaskan island’s deer

The key to weathering rapid sea-level rise may lie in a Massachusetts salt marsh

When deer disappear off the menu, hungry wolves turn to sea otters

Deep-sea devices detect earthquakes, singing whales and explosions of a sinking ship — 50 highly-sensitive seismometers were placed on the floor of the Atlantic Ocean, in a quest to depict the Earth’s interior down to ~2,800 km depth

Vulnerability of red sea urchins to climate change depends on location

Secrets of Marine Biology: How Four Genes Turned Whales Into Giants of the Sea

Greenland Ice Sheet Warmest In At Least 1,000 Years As Scientists Warn Melting Ice Will Accelerate Sea-Level Rise

Help in the hunt for neutrinos while exploring deep-sea ecosystems

New Bay Area maps show hidden flood risk from sea level rise and groundwater

Marine heatwaves could wipe out all common sea stars by 2100

Marine heat waves could wipe out all common sea stars by 2100