Exploring Vents: Technology

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Modern oceanography began with the Challenger Expedition (1872-1876). On that voyage new methods for dredging the seafloor and sampling the ocean water were tried, and new technologies, like deep-sea winches and specialized ropes for lowering equipment were tested. In the 125 years since the Challenger Expedition, oceanographic science and the technologies used to study the ocean have advanced significantly.

We can now resolve the topography of the ocean basins on scales that span thousands of kilometers using satellite altimetry data, as well as map specific seafloor features in great detail (sub-meter resolution) using submersible vehicles. Many of these advances have resulted directly from new technologies used to sample, measure, and map the ocean and seafloor. Knowing the position and morphology of the global Mid-Ocean Ridge (MOR) crest is essential to locate areas that may have greater numbers of hydrothermal vent sites. This knowledge helps to focus where detailed multibeam mapping and submersible studies are needed to locate new vents.

Research ships have been the primary vehicles in which scientists go to sea and carry out their studies. Traditional ship-based oceanography will continue to play a major role in the oceanographic sciences in the 21st century, but the sensor and submersible technologies available for deployment from the ships have significantly increased the scope, efficiency and accuracy of the field experiments. Some of the newest sensors and vehicles also permit time-series measurements of oceanographic phenomena, including seawater temperature, turbidity, current speed and chemistry. We now know that taking continuous measurements over time spans of minutes, months and decades gives us a much better understanding of the relationships between physical, chemical and biological processes in the ocean and at the seafloor.

Submersible vehicles that permit exploration of the ocean and seafloor have rapidly developed over the last 15 years, advancing beyond research submarines that carry a pilot and a few observers, to sophisticated remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs). These new robotic vehicles have significantly expanded the depth and geographic range of our explorations and the efficiency with which we can access the deep ocean and seafloor. The fiber-optic cable that tethers the ROV to the surface ship transmits gigabytes of data from the depths to the surface ship and supplies power to operate the vehicle propulsion, navigation, sampling and light systems. Dozens of scientists can participate in seafloor observations and sampling for days at a time, around the clock, when using ROVs.

21st century seafloor exploration technology will also rely on several key areas of engineering including satellite connectivity and autonomous vehicles. Global communications via satellites enable smart sensors on autonomous vehicles to telemeter data to shore from the farthest reaches of the ocean basins. AUVs can now be programmed to conduct surveys over hundreds of square kilometers of seafloor to search for hydrothermal plumes and gradients in those plumes that can lead to seafloor vent sites. New algorithms that use the real time data collected during a mission permit the AUVs to be ‘smart’ and alter their programmed survey pattern to ‘home-in’ on a suspected seafloor vent site.

Several types of AUVs have been developed to work in both shallow and some of the deepest regions of the oceans. The shapes of these vehicles have been designed to allow them to move through the water very efficiently, using low-levels of power so that they can stay submerged for a few days. Using the latest in lithium-ion battery technology, AUVs can normally cover hundreds of kilometers of track while collecting data about seawater properties, high-resolution bathymetry, and even photographs of the seafloor.

The latest developments in ocean science and technology have led to major international efforts to establish ocean observing systems. Ocean floor obser vatories are being developed in coastal areas to monitor the geology, chemistry and biology of important fisheries and study the impact of humans and extreme climate events. Seafloor observatories are also planned in oceanic trenches adjacent to major population areas, like in Japan and offshore Washington and Oregon where the large earthquakes occur and where tsunamis can be generated. Ocean floor observatories are also planned at select mid-ocean ridges to study crustal generation processes that include time-series studies of hydrothermal vents and the impacts that volcanic eruptions and earthquakes have on vent fluids and animal communities.

Examples of Deep-Towed Vehicle Systems for Deep Sea Research and Exploration
(Systems that can operate at depths ≥1000 m)

Vehicle Operating
Operating Depth
TowCam WHOI, USA 6,500 Photo imagery; CTD;
volcanic glass samples;
water samples
Deep-Tow Survey
COMRA, China 6,000 Sidescan, bathymetry;
sub-bottom Profiling;
DSL-120A HMRG, USA 6,000 Sidescan; bathymetry
IMI-30 HMRG, USA 6,000 Sidescan; bathymetry;
sub-bottom profiling
Scampi IFREMER, France 6,000 Photo & video imagery
Système Acoustique
Remorqué (SAR)
IFREMER, France 6,000 Sidescan; sub-bottom
profiling; magnetics;
SHRIMP NOC, UK       6,000 Photo & video imagery
TOBI NOC, UK       6,000 Sidescan; bathymetry;
BRIDGET NOC, UK 6,000 Geochemistry
Deep Tow 6KC JAMSTEC, Japan       6,000 Photo & video imagery
Deep Tow 4KC JAMSTEC, Japan       4,000 Photo & video imagery
Deep Tow 4KS JAMSTEC, Japan 4,000 Sidescan; sub-bottom

(see key to abbreviations)


Human Occupied Vehicles (HOVs) for Deep Sea Research and Exploration
(Vehicles that can operate at depths ≥1000 m)

  Vehicle   Operating Organization Maximum Operating Depth (m)
(under construction)
COMRA, China 7,000
Shinkai 6500 JAMSTEC, Japan 6,500
Replacement HOV
(in planning stages)
MIR I & II P.P. Shirshov Institute of Oceanology, Russia 6,000
Nautile IFREMER, France 6,000
Alvin NDSF, WHOI, USA 4,500
Pisces IV HURL, USA 2,170
Pisces V HURL, USA 2,090
Johnson-Sea-Link I & II HBOI, USA 1,000

(see key to abbreviations)

Remotely Operated Vehicles (ROVs) for Deep Sea Research and Exploration
(Vehicles that can operate at depths ≥1000 m)

  Vehicle   Operating Organization Maximum
Operating Depth (m)
Nereus (hybrid)          
(under construction)
NDSF, WHOI, USA 11,000
Kaiko 7000 JAMSTEC, Japan 7,000
Isis      NOC, UK 6,500
Jason II NDSF, WHOI, USA 6,500
ATV SIO, USA 6,000
CV (Wireline Reentry System) SIO, USA 6,000
Victor 6000 IFREMER, France 6,000
ROV (on order) NOAA Office of Ocean Exploration, USA 6,000
ROPOS CSSF, Canada 5,000
Tiburon MBARI, USA 4,000
Quest Research Centre Ocean Margins, Germany 4,000
Hercules Institute for Exploration, USA 4,000
Sea Dragon 3500 COMRA, China 3,500
Hyper Dolphin JAMSTEC, Japan 3,000
Aglantha Institute of Marine Research, Norway 2,000
Ventana MBARI, USA 1,500
Cherokee Research Centre Ocean Margins, Germany 1,000

(see key to abbreviations)

Examples of Autonomous Underwater Vehicles (AUVs) for Deep Sea Research and Exploration
(Vehicles that can operate at depths ≥1000 m)

  Vehicle   Operating Organization Maximum
Operating Depth
Dorado Class MBARI, USA 6,000
CR-01, CR-02 COMRA, China 6,000
Sentry WHOI, USA 6,000
REMUS Class WHOI, USA 6,000
Autosub 6000
(under construction)
NOC, UK 6,000
Autonomous Benthic Explorer NDSF, WHOI, USA 5,500
Explorer 5000 Research Centre Ocean Margins, Germany 5,000
(under construction)
WHOI, USA 5,000
Urashima (hybrid) JAMSTEC, Japan 3,500
Aster x IFREMER, France 3,000
Bluefin AUV Alfred Wegener Institute, Germany 3,000
Bluefin 21 AUV SIO, USA 3,000
Odyssey Class MIT, USA 3,000
SeaBED WHOI, USA 2,000
Autosub 3 National Oceanography Centre, UK 1,600
Spray Gliders WHOI, USA 1,500
Seaglider U. Washington, USA 1,000



COMRA – China Ocean Mineral Resources R & D Association

CSSF – Canadian Scientific Submersible Facility, Canada

HBOI – Harbor Branch Oceanographic Institution, USA

HMRG – Hawaii Mapping Research Group, USA

HURL – Hawaii Undersea Research Laboratory, USA

IFREMER – French Research Institute for Exploration of the Sea

JAMSTEC – Japan Marine Science & Technology Center, Japan

MBARI – Monterey Bay Aquarium Research Institute

NDSF, WHOI – National Deep Submergence Facility, Woods Hole Oceanographic Institution, USA

NOC – National Oceanographic Centre, Southampton, UK

SIO – Scripps Institution of Oceanography, USA

WHOI – Woods Hole Oceanographic Institution, USA