Ocean

One, four or five? Not all experts agree on the number of oceans on our planet.

A new study cataloged all the species uncovered by research expeditions in the Clarion-Clipperton Zone, which has become a potential hotspot for deep-sea mining.

The Sentinel-6 Michael Freilich satellite recorded Kelvin waves moving eastward across the Pacific — a phenomenon often considered a precursor to El Niño.

A huge drop in sea levels trapped extremely salty water in the Indian Ocean, which then gushed into the Atlantic when currents changed 15,000 years ago.

NOAA researchers have predicted that an ocean-heating event known as El Niño is probably going to arrive in the next few months and persist into 2024.

Researchers have discovered that unusual swirling "slicks" that occasionally appear on the Baltic Sea are actually made from floating tree pollen.

Scientists used high-resolution radar satellites and discovered a ‘mind boggling’ 19,000 volcanoes.

Heat waves are reaching the bottoms of Earth's oceans, and that could be a big problem for the creatures that live there.

In samples of organic-rich black shale, scientists found evidence for oxygen depletion and hydrogen sulfide expansion in ancient seas.

The bottom of the Mariana Trench is about 35,876 feet (10,935 meters) deep, making it deeper than Mount Everest is tall.