40,000 Mile Volcano

Mapping New Worlds

Many scientists have acknowledged that we have better maps of the Moon and Mars than we do of Earth’s ocean floor. So much of the ocean is still a mystery.

Deep beneath the ocean’s surface are incredibly peculiar creatures, extreme temperatures, and geological features that look like something out of a sci-fi film. Thanks to technological advances, a network of cables, sensors, and data collecting equipment we can explore previously unseen parts of the murky ocean floor. These tools help us gain insight into the mysteries of volcanism, marine biology, and tectonic activity that were previously unexplained.

Molten lava erupts underwater along the seafloor.
(Doug Perrine/naturepl.com)

Broken rocks, cracks and volcanic vents on the ocean floor along the Mid-Atlantic Ridge become homes for some of Earth's most peculiar creatures. Under extreme heat and pressure, this mid-ocean ridge region is one of Earth's most unique habitats.
(NOAA Photo Library/ The Lost City 2005 Expedition)

We know that slabs of Earth’s outermost layer of rigid rock, or tectonic plates, move slowly as a result of Earth’s internal energy. When these plates move, they create fascinating geological features and violent events. One of the most compelling expressions of these tectonic interactions is a connected system of underwater volcanoes that extends around our entire globe.

Envision our Earth fractured by a strip of volcanoes nearly 40,000 miles long. These mid-ocean ridges encircle our planet like the seams of a baseball. Located deep below the ocean’s surface, the ridges result from the divergent boundaries, where two tectonic plates are spreading apart. Huge rift valleys and extreme temperatures exist at these boundaries.

Global Rift Locations

This map shows locations of tectonic plate boundaries and known mid-ocean ridge vents.

Robotic equipment has recorded temperatures over 400°C (752°F) in these underwater hot springs, called hydrothermal vents. These vents are created when cool water seeps through cracks in rock and is heated by magma and hot rocks. The superheated water spews through the ocean floor. Scientists have uncovered numerous vents under the ocean since the 1970s. Vents commonly occur at the site of divergent boundaries.

It is hard to imagine anything living in or near these extreme conditions. However, some life not only survives, but thrives in this environment. Scientists have observed many species of alien-like life. Here, bacteria help to sustain this unique ecosystem. Captivating and unexpected creatures, such as tubeworms, spider crabs, odd-looking shrimp, and diverse fish populations live in the hydrothermal vents.

Deep-sea crabs are one of the many inhabitants of the Mid-Atlantic Ridge.
(MARUM, Center for Marine Environmental Sciences, University of Bremen)
Deep-sea jellyfish make their home along the unique habitat of the Mid-Atlantic Ridge.
(NOAA Photo Library/ The Lost City 2005 Expedition)
Over 3,000 meters beneath the ocean's surface, hydrothermal vents help to sustain diverse aquatic communities.
(MARUM, Center for Marine Environmental Sciences, University of Bremen)
Tube worms, anemones, and mussels thrive in the environment around the Mid-Atlantic Ridge and seafloor hydrothermal vents.
(NOAA Okeanos Explorer Program, Galapagos Rift Expedition 2011)
On a smaller scale, deep-sea vents are home to snails and bacteria, which benefit from the high temperature environments surrounding the vents.
(Dr. Charles Fisher/Woods Hole Oceanographic Institute)

In other places along this tremendous volcanic frontier, denser oceanic plates dive under the lighter continental plates. These interactions are called convergent boundaries, which can result in subduction zones. At these boundaries, trenches form, along with a line of volcanoes. Here vents emit carbon dioxide and lava into the ocean.

The future is full of potential for new discoveries about these sub-ocean features. New creatures, landforms, and more information about our changing Earth await scientists. Investment in scientific infrastructure is fueling the next generation of underwater discoveries. Scientists have installed networks of cables and many sensors to improve our understanding of secrets that remain underneath the ocean.

They deploy underwater drones and use satellites in space to monitor the ocean floor. Instruments like seismometers, temperature gauges, pressure sensors and underwater cameras continuously reveal new data propelling science toward the future.

So, what still lies beneath our oceans? We don’t know, but it is clear that there is much more to learn.

Scientists use Remotely Operated Vehicles (ROVs), like Hercules pictured here, to investigate deep regions of the ocean along the Mid-Atlantic Ridge.
(NOAA Photo Library/ The Lost City 2005 Expedition)

PLATE BOUNDARIES

The Mid-Atlantic Ridge

A 40,000-Mile Long Volcano

Mapping New Worlds

Global Rift Locations

Tamu Massif

The Mid-Atlantic Ridge

San Andreas Fault

Maar Volcanoes

Fire Under the Ice

Yellowstone