Thermal Vents, Microbial Mats & Deep Sea Mirrors

deep sea mirror
Seawater and hydrothermal fluids collected under a ledge create the illusion of an upside-down mirror – more than a mile below the ocean surface. Click on the screenshot to view a video from Schmidt Ocean Institute.

THE MISSION WAS TO STUDY DEEP SEA HYDROTHERMAL VENTS. THE BONUS REWARD WAS MESMERIZING UPSIDE-DOWN DEEP SEA MIRRORS – at least, the illusion of mirrors – under ledges some 6,500 ft/2,000 m under the sea.

The Schmidt Ocean Institute scientists on the research vessel Falkor were seeking earlier this year to learn about the life, geology and chemistry of little-explored deep thermal vents in the Gulf of California’s Guatmas Basin.

And, using a remotely operated vehicle (ROV) named SuBastian, they found venting mineral towers up to 23 meters high and 10 meters across. They identified minerals laden with metals and fluids that were highly sulfidic. And they found those seemingly inhospitable environments teeming with biodiversity and potentially unknown fauna.


As chemicals accumulate around vents and build mineral towers, they sometimes create “flanges,” or horizontal overhangs. The upside-down “mirror” illusion is created when superheated water, rising above cold ocean waters, is trapped under a jutting flange. The cool/superhot temperature difference causes light to slow, resulting in a surface that resembles a mirror. There to collect hard data and samples, the researchers found the sight mesmerizing.

Alas, the effect only works when viewed at a certain angle. As soon as the ROV moves, the mirror disappears.

deep sea mirror
Worms, microbes and other lifeforms are abundant around the deep sea thermal vents.


The objective of the exploration was to study habitat-specific microbes around the vents and seeps and assess how they relate to the structures and megafauna there. This includes collecting sediment samples for later analysis and other experiments. A central thread of the sample collections involved studies of methane sampling.

But beyond the scientific data-analysis of such sites, there were the views. Not just upside-down deep sea “mirrors” but the beautiful landscape and colorful life.

“We discovered remarkable towers where every surface was occupied by some type of life,” says University of Georgia professor Dr. Mandy Joye, the expedition’s lead scientist.

“The vibrant colors found on the ‘living rocks’ was striking and reflects a diversity in biological composition as well as mineral distributions. This is an amazing natural laboratory to document incredible organisms and better understand how they survive in extremely challenging environments.”


As geographically remote and as deep as the site was, human debris found its way there. The researchers observed a great deal of trash, including fishing nets, deflated Mylar balloons and even discarded Christmas trees during their explorations.

PRINCIPAL SOURCES: Otherworldly Mirror Pools, New Lifeforms, and Mesmerizing Landscapes Discovered on Ocean Floor,” Schmidt Ocean Institute News Department; “Scientists Spot Beautiful Optical Illusion at Bottom of the Sea,”