There are still many mysteries surrounding sea floor hydrothermal vent complexes, also known as black smokers. These hot springs on the bottom of the ocean form when a body of magma rises towards the seabed, such as on mid-oceanic ridges or volcanic arcs.
The biological, chemical, and geological relationships in these areas are complicated and intricate, intertwined in ways that are not completely understood. The big picture evades even the top scientists, as we are unable to experience this hostile deep-sea environment in ways we would look at and explore a landscape on land. But what if we could strap on a headset and go for a swim five miles under the ocean without leaving our homes?
The plumes rising from hydrothermal vent “chimneys” are not really smoke, but mineral-laden, super-heated water that doesn’t boil due to the pressure of tons of ocean water above
Recently, the Schmidt Ocean Institute—a non-profit organization that works to advance oceanographic research and knowledge with the use of the latest technology—launched an expedition called the “Virtual Vents Cruise.” The goal of the trip was to survey the sea floor by getting as close as possible—only they wanted to bring the sea floor to the surface, rather than going down themselves.
Working along Tonga’s Northeastern Lau Basin in the middle of the Pacific Ocean, researchers collected thousands of images using a deep-sea submersible. Through these images, the scientists created a digital model of an entire hydrothermal vent field that can be explored using virtual reality simulators.
High-performance computers use the same graphics technology as the gaming industry to create a first version of the terrain model to check for accidental data gaps
“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. Dr. Kwasnitschka led the expedition along with other members of the team from a variety of institutions, including the US Geological Survey, Memorial University, and the University of Victoria, B.C.
These models will eventually form the reference for layered environmental maps at unprecedented resolution that will help to define the nature of venting, fluid temperature/chemistry, and animal clusters in these unique environments. The final product will be the first open access, virtual model of an entire vent field, not just individual chimneys. This innovative survey approach will spark new strategies of deep ocean floor research and create an immersive tool for public engagement.
Dr. Mark Hannington watches a live feed in the library on board RV Falkor, which is equipped with customizable screens in nearly every room
ROV ROPOS awaits deployment on the aft deck and team members go over last-minute adjustments in preparation for a dive exploring hydrothermal vent fields
All About the Imagery
The star of the show is a bright-yellow robot, roughly the size of a Mini Cooper car. The Remotely Operated Platform for Ocean Sciences (or ROV ROPOS) is actually five times as heavy as that automobile, but it more than makes up for the extra weight with all of the impressive technology aboard.
Mounted to the ROV is a resolution survey camera, which was developed around the Canon EOS 6D DSLR, paired with an 8–15mm fisheye lens. A powerful LED strobe is used to light the surveyed site as the ROV scans from just 15 feet above the sea floor. An image is produced every second for the entire dive (the longest of which was just over 73 hours on this cruise). While the stills are being taken, an additional Sony A7s full-frame mirrorless camera with a fisheye zoom captures high-sensitivity UHD video footage.
Chief Scientist Tom Kwasnitschka prepares the camera and video systems, housings, and wiring on the ROV before a dive
The cameras are encased in titanium housings with dome ports that withstand pressures at depths of 6,000 metres (19,700 feet). This means that construction of the housing is considerably stronger than those for scuba diving—even the dome port glass is three inches thick. Special care is needed to align the cameras behind these windows, and focusing is accomplished remotely from the computer lab. As the ambient temperature drops to around 40°F in the deep ocean, researchers added nitrogen gas into the housings to prevent flogging as the cameras heat up.
More than five miles above the ROV, the technology aboard research vessel Falkor is equally impressive. A powerful workstation warps the fisheye image in real time using “Video Stitch Vahana” software, before it is viewed real time using an Oculus Rift head-mounted display. Thanks to impressive telecommunications capabilities on the research vessel, viewers from around the world watched a live-streamed HD version of the video on the Schmidt Ocean Institute’s YouTube page.
Those aboard the ship could wear virtual reality (VR) goggles and view the underwater scene in real time
ROV ROPOS begins its descent to a hydrothermal vent field, headed more than 8,100 feet below the ocean’s surface
Creating Deep-Sea 3D Models
Even in the middle of the Pacific, researchers with high-performance computers create a first version of the terrain model to check for accidental data gaps. When gaps are found, the ROV circles the vents, looking at them from all sides. In this step, a stereo camera system is employed that delivers a real-time 3D preview of the structures. After all, it is important to know what has already been covered, and what has not. During the 149 hours of dive time, researchers collect a total of 10TB of data, including 129,000 DSLR images and 100 hours of UHD video.
There are over 32 screens in the control room. The room is kept dark so everyone can see their readings better, including those piloting the ROV, researchers watching live feeds, and technicians monitoring sensors
Despite the harsh environment, which would be deadly to most animals, some species do live around the vents—including snails, mussels, crabs and shrimp
With the vast amount of data comes a challenge seemingly as insurmountable as taking the images in the first place—turning the images into 3D models. Photogrammetry is the process of making exact measurements from many overlapping photographs—the computer “sees” the world similar to how we use our two eyes. Using field-tested, state-of-the-art photogrammetric survey techniques, the team will create three dimensional, full-color terrain models at 1-cm resolution. The process is expected to take the rest of the year to complete.
When complete, these models can then be examined by scientists who can be anywhere in the world, free of the hurry and physical limitations of deep-sea expeditions. But the uses also extend to non-professionals. In part due to the computer graphics technology developed in the gaming industry, the data can be explored on a laptop much in the same way as through high-end virtual reality simulators used at universities. Museums equipped with similar science visualization theaters are able to immerse their visitors in a deep-sea world based on actual data.
About the width and length of a sub-compact car (but twice as tall), ROV ROPOS is deployed from the aft deck of research vessel Falkor via crane into the water to begin the dive