Seafloor & below

Key Takeaways

The seafloor holds Earth’s longest mountain ranges, deepest trenches, tens of thousands of seamounts, and countless volcanoes and hydrothermal vents.
These features drive plate tectonics, shape ocean chemistry, and host ecosystems powered by chemical energy instead of sunlight.
WHOI reaches these depths with vehicles like HOV Alvin and ROV Jason to study one of the planet’s last unexplored frontiers.

Beneath the waves lies a hidden landscape of mountain ranges, trenches, seamounts, hydrothermal vents, and volcanoes that shapes the whole planet. WHOI scientists and engineers explore this seafloor with crewed submersibles and robots to reveal how Earth builds, moves, and sustains life.

Beneath the waves lies a vast, dynamic world that shapes the ocean from the bottom up. The seafloor is not a flat expanse of mud, but a complex and geologically active landscape comprising towering mountains, deep trenches, erupting volcanoes, and vast underwater plains.

At mid-ocean ridges, tectonic plates pull apart and give rise to new seafloor through volcanic activity. These spreading centers are also home to hydrothermal vents — cracks in the Earth’s crust where hot, mineral-rich fluids gush into the ocean, supporting unique ecosystems that thrive without sunlight. In contrast, ocean trenches occur areas where tectonic plates collide, driving one plate deep beneath another in dramatic, deep-sea subduction zones.

Seamounts — underwater mountains that rise from the seafloor — are often biological hotspots that provide habitat for marine life. Natural oil that seeps from cracks in the seabed offers clues about Earth’s geologic processes.

Studying the seafloor helps scientists understand how Earth’s core, the ocean, and life on our planet are connected to each other.

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