Mars may have been a "blue planet" with an ocean the size of today's Arctic Ocean, a new study suggests.

A conveyor belt of ocean water that loops the planet and regulates global temperatures could be heading for a tipping point.

The Arctic Ocean, once locked in a vault of thick, old ice, now is transforming at lightspeed. Temperatures there are increasing at up to four times the rate of the planet overall, melting sea ice ...

The deepest reaches of the Arctic Ocean contain one of the most desolate environments on our entire planet. It is known as Loki’s Castle, a large field of hydrothermal vents on the sea floor that’s ...

Far below the ice, in a realm long assumed to be almost lifeless, scientists have stumbled on a thriving oasis nearly 2.5 miles under the Arctic Ocean. The discovery, centered on a methane hydrate ...

As the Arctic Ocean loses its sea ice due to climate change, sunlight penetrates deeper into the water and encourages the growth of tiny plant-like organisms (phytoplankton). But to thrive, they need ...