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A hydrothermal vent chimney at the Endeavour Segment, with red and white tube worms colonizing the area. Credit: National Oceanic and Atmospheric Administration
A slice of the ocean floor off the coast of Washington State is like a scene from a fantasy land. Tapered spires climb high above the seabed, with some of them shooting boiling-hot water into the frigid depths. Tubeworms and other exotic life surround the spires. And small tremors jiggle the whole tableau several times a day.
The location is the Endeavour Segment of the Juan de Fuca Ridge, a couple of hundred miles off the coast. It’s at the edge of one of the plates that make up Earth’s crust. The plate is moving, causing the sea floor to spread apart. Molten rock bubbles up to fill the gap, forming new crust. The fresh rock builds a ridge with a steep chasm running down its center.
The Endeavour Segment lies along this ridge. Its middle is one of the most active regions on the ocean floor. Water trickles down into the seabed, where it’s heated by molten rock. It squirts back into the ocean through hot springs, known as hydrothermal vents. Minerals in this hot water build up around the vent, forming tall chimneys. Microbes that use the minerals as an energy source form the first link in a food chain that includes worms and sea stars.
There are more than 800 of these chimneys in the heart of the Endeavour Segment, towering up to 15 stories high. And the landscape is constantly changing. Pockets of molten rock below the ocean floor move, creating several tremors every day. That causes some of the chimneys to shut down, and new ones to form — reshaping this fantasy land at the bottom of the sea.
