Stunning “Mirror” Effect at Hydrothermal Vents

Why does it look like there is a mirror at the bottom of the ocean? We captured this outstanding optical effect on camera as ROV Hercules descended 1285m deep on the Smoke and Mirrors site of the Endeavour Vent Field. The reflecting effect of these shallow pools witnessed underneath volcanic chimney ledges (aka flanges) is created when hot, buoyant hydrothermal fluids flow outwards and up over the edge. 

"In the flange pool, the water is warm, and depending on phase separation of the fluid, different in salinity. The light propagating through the ambient ocean water hits the interface of the vent fluids and there is a reflection," says Dr. Steve Mihaly, Ocean Networks Canada Senior Staff Scientist. 

The Endeavour hydrothermal vent field is one of the most hostile environments on Earth. Located in this seemingly uninhabitable seascape are at least a dozen species (including the palm worms spotted in this video) that are found nowhere else in the world. In 2003, it was classified as a Marine Protected Area (the first in Canada) and the first hydrothermal vent ecosystem protected in the world! 

Learn more about our NA151 expedition with Ocean Networks Canada to support their NEPTUNE observatory, an 800-kilometer (500-mile) loop of fiber optic cable located off the west coast of Canada.