The deep ocean remains largely unexplored by humans.

The deep ocean remains largely unexplored by humans.

The world's longest mountain chain is actually underwater — the Mid-Ocean Ridge stretches over 65,000 km.

NOAA's exploration of deep ocean vents has discovered ecosystems entirely dependent on chemosynthesis rather than sunlight.

The Dead Sea is so salty that nothing larger than bacteria can survive in it, and swimmers float effortlessly.

Many deep-sea fish have transparent or nearly invisible bodies.

Coral reefs are expected to decline by 70–90% if global temperatures rise 1.5°C above pre-industrial levels.

Greenland's ice sheet is melting at accelerating rates, contributing significantly to global sea-level rise.

Ancient oceans once covered much of Earth's surface.