SEVENSEAS Marine Conservation & Travel Issue 14, July 2016 - Page 42

The Most Dynamic Depths ­Exploring Hydrothermal Vents

Experiencing and studying inhospitable underwater environments

ydrothermal vent fields are some of the most dynamic and beautiful areas on earth. Stunning geologic columns rise

up with plumes of hydrothermal fluid billowing out, taking the appearance of smoke leaving raw and primitive chimneys. These structures are circled by rare, alien­looking animals: “hairy” yeti crabs, pure white rock lobsters, bright orange octopi, skeletal cusk­eels, as well as colonies of anemones and tubeworms that bloom like flowers on the seafloor.

As aesthetically alluring as these environments are, there are few human visitors since hydrothermal vents are virtually impossible to visit. Thousands of meters below the ocean’s surface, the vents present many access challenges. These hot springs on the bottom of the ocean form when a body of magma rises towards the seabed on mid­oceanic ridges or volcanic arcs, the boundaries of oceanic plates. As such, temperatures can range enormously, from ambient deep­sea water near freezing to jets of fluid heated by magma to 400 °C (750 °F) in a very short distance. The super­heated water doesn’t boil, because the water­pressure is so great at these depths: the pressure at a hydrothermal vent 2,500 meters deep is 250 atmospheres, or 3,672.5 pounds per square inch ­ try putting the weight of a tow­truck on your big toe! These areas are so difficult to reach, they weren’t even discovered by humans until 1977 ­ we have known of their existence for less than 40 years.

Schmidt Ocean Institute's Research Vessel Falkor recently set out to explore unique and remote vent systems with two cruises focused in the Lau Basin, in between Fiji and Tonga. The first cruise (nicknamed “Virtual Vents”), led by Dr. Tom Kwasnitschka, focused on documenting changing aspects of the area using cutting­edge technologies. The following cruise, led Dr. Charles Fisher and Dr. Peter Girguis shifted attention to the unique biological species of these systems, and as such became known as the “Vent Life Expedition.”

Both expeditions used a Remotely Operated Vehicle (ROV), ROPOS, equipped with a suite of cameras and sensors to gather footage and collect samples. Over the course of both research cruises, fourteen dives took place at six hydrothermal vent fields, resulting in 170 hours of live image streaming to Schmidt Ocean Institute’s YouTube channel.

Virtual Vents

The goal of the Virtual Vents cruise was to get as close to walking on the seafloor as possible ­ the twist was that researchers digitally brought the seafloor the surface, instead of going down themselves. From the imagery gathered using advanced underwater survey technology, a digital model of an entire hydrothermal vent field will be created that can be explored using virtual reality simulators or VR head mounted displays. “To work with a simulation is not the real thing, but it surely is next best to being there in person,” explains Dr. Tom Kwasnitschka, of GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany. Tom and his team are working to produce a series of 1­cm resolution 3D models of vent groups, which will then be used to create layered environment maps that will help to define the nature of venting, fluid temperature/chemistry, and animal clusters in these perplexing environments.

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By Logan Mock­Bunting

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