Nereus Underwater Vehicle Imploded in Kermadec Trench on 10 May 2014

Summary: Nereus underwater vehicle is a hybrid, autonomously and remotely operated vehicle built by Woods Hole Oceanographic Institution for deep ocean missions.

recovery of Nereus underwater vehicle aboard RV Cape Hatteras during Mid-Cayman Rise expedition in October 2009: Woods Hole Oceanographic Institution/NASA/JPL-Caltech, Public Domain, via Wikimedia Commons

Nereus underwater vehicle was designed and built by engineers in the Deep Submergence Lab (DSL) at Cape Cod, Massachusetts’ Woods Hole Oceanographic Institution (WHOI) as a one-of-a-kind, portable Hybrid Remotely Operated Vehicle (HROV).

Nereus was given the capability of descending to depths of up to 36,089 feet (11,000 meters; 6.835 miles) in the hadal zone, the deepest part of the ocean. Nereus was also designed for withstanding crushing water pressures over 1,000 times the standard atmospheric pressure at sea level.

The unique hybrid-vehicle design allowed Nereus to switch between two modes. As a free-swimming, autonomous underwater vehicle (AUV), Nereus conducted wide-area mapping and surveying. As a tethered, remotely operated vehicle (ROV), Nereus engaged in close-up seafloor imaging and sampling of biological organisms and rocks.

Nereus’ innovative tether had the diameter of a human hair and a length of 25 miles (40.2 kilometers). The tether was adapted from fiber-optic technology by the Navy’s Space and Naval Warfare Systems Center Pacific (SSC Pacific) for transmission of high-resolution images and data in real time.

In support of the development of the Nereus underwater vehicle, funds totaling $8,449,000 were provided by: National Science Foundation (NSF), at $6.3 million; Office of Naval Research (ONR), at $1.1 million; National Oceanic and Atmospheric Administration (NOAA), at $549,000; and The Russell Family Foundation (TRFF), at $500,000.

Woods Hole’s rechargeable, lithium battery-operated underwater vehicle was known simply as Hybrid Remotely Operated Vehicle prior to a nationwide contest in 2006. The contest elicited 22 entries from junior high, high school and college student participants in Monterey, California’s Marine Advanced Technology Education (MATE) Center.

Selected at an awards banquet on Sunday, June 25, 2006, at NASA’s Johnson Space Center in Houston, Texas, the winning name of Nereus was submitted by a team of six sophomores, juniors and seniors, headed by Kelly Miller, chemistry and oceanography teacher at Monterey High School. As a shapeshifting god, with a man’s torso and a fish tail, in Greek mythology, Nereus (Ancient Greek: Νηρεύς), which rhymes with “serious,” exemplified the HROV’s shapeshifting modes.

First sea trials, which began in November 2007, were conducted in the Pacific Ocean near Oahu, Hawaii. Mobilization and demobilization of the successful trials took place aboard RV Kilo Moana. The small waterplane area twin hull oceanographic research vessel (SWATH RV) is owned by the Office of Naval Research and operated by the University of Hawaii as part of the University-National Oceanographic Laboratory System (UNOLS) coordinated research vessel fleet.

On May 31, 2009, Nereus completed its first dive deep into the world’s deepest ocean trench, the western North Pacific’s Mariana Trench. Nereus descended to the hadal ocean depth of 35,770.99 feet (10,903 meters), at a site near the deepest known spot in Challenger Deep, the valley in the southeastern Mariana Trench with a depth recalibrated in 2012 at 36,069 feet (10,994 meters), plus or minus 131 feet (40 meters). The Challenger Deep has an extreme water pressure, at 8 tons per square inch, 1000 times stronger than standard atmospheric pressure at sea level. The dive lasted for 26 hours, with 8.5 hours for descent, 10.75 hours in the trench and 6.5 hours for autonomous ascent.

On Saturday, May 10, 2014, Woods Hole Oceanographic Institution issued a sad news release announcing the loss of Nereus at 10 p.m. Eastern Daylight Time Friday, May 9, in the seventh hour of a planned nine-hour dive into the deepest extent of the Kermadec Trench. The world’s fifth deepest ocean trench lies in the western South Pacific northeast of New Zealand’s North Island.

At the time of loss of contact with RV Thomas G. Thompson, Nereus had reached a depth of 32,775.59 feet (9,990 meters; 6.2 miles) and had logged 30 days of a 40-day, deep-ocean trench expedition. Timothy M. Shank, Assistant Scientist in WHOI’s Biology Department, was directing the expedition as chief scientist of Hadal Ecosystem Studies (HADES), a three-year project funded by the NSF.

Debris floating up to the sea surface from the dive site indicated that Nereus had suffered a catastrophic implosion, with the intense pressure from over six miles of water column as the likely cause.

Dr. Shank honored Nereus as a “one-of-a-kind vehicle” that provided “during its brief life ... amazing insights ...” into never before seen or explored ocean depths.

Explorer and filmmaker James Cameron movingly expressed feelings akin to the loss of a friend. He also shared his now impossible dream of a joint, hadal-depth dive of Nereus with Deepsea Challenger, the deep-diving submersible that he piloted to Challenger Deep on March 26, 2012.

While acknowledging the riskiness of extreme exploration and applauding the absence of human injury in the loss of Nereus, Laurence P. Madin, WHOI's Executive Vice President and Director of Research, affirmed the private research and higher education facility's ongoing commitment to the design, construction and operation of ever more advanced vehicles for oceanic exploration and understanding of the oceans' most extreme and remote depths.

The legacy of high achievements does not end with the loss of Nereus but instead continues to play out as WHOI marks over 8.5 decades of getting to know the world's oceans.

Nereus lost contact with RV Thomas G. Thompson at 10 p.m. Eastern Standard Time, Friday, May 9, 2014; RV Thomas G. Thompson over Maug caldera, Northern Mariana Islands, April 8, 2004: NOAA (National Oceanic and Atmospheric Administration), Public Domain, via NOAA Ocean Explorer

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Team recovers Nereus aboard RV Cape Hatteras during Mid-Cayman Rise expedition in October 2009: Woods Hole Oceanographic Institution/NASA/JPL-Caltech, Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Nereus_(underwater_vehicle)_hydro20100720-full.jpg

Nereus lost contact with RV Thomas G. Thompson at 10 p.m. Eastern Standard Time, Friday, May 9, 2014; RV Thomas G. Thompson over Maug caldera, Northern Mariana Islands, April 8, 2004: NOAA (National Oceanic and Atmospheric Administration), Public Domain, via NOAA Ocean Explorer @ https://oceanexplorer.noaa.gov/explorations/04fire/logs/hirez/thompson_maug_hirez.jpg

For further information:

Bowen, Andrew D., et al. Field Trials of the Nereus Hybrid Underwater Robotic Vehicle in the Challenger Deep of the Mariana Trench. Fort Belvoir VA: Defense Technical Information Center, June 2010.
Available @ http://dtic.mil/dtic/tr/fulltext/u2/a527831.pdf

"Five Deepest Ocean Trenches: Deep Plunges in Pacific Ocean Hadal Zone." Earth and Space News. Thursday, Oct. 1, 2015.
Available @ https://earth-and-space-news.blogspot.com/2015/10/five-deepest-ocean-trenches-deep.html

GeoBeat News. "Deep Water Vessel Implodes 6 Miles Down." YouTube. May 12, 2014.
Available @ https://www.youtube.com/watch?v=phAwjokrxkQ

Kostel, Ken. “A sad day.”Woods Hole Oceanographic Institution Blogs > Kermadec Trench Expedition 2014. May 10, 2014.
Available @ http://web.whoi.edu/hades/a-sad-day/

“Remembrances & Condolences for HROV Nereus.” Woods Hole Oceanographic Institution > About WHOI > History & Legacy > Legacy of Exploration. Last updated: Jan. 6, 2015.
Available @ http://www.whoi.edu/main/nereus/condolences

“Robotic Deep-Sea Vehicle Lost on Dive to 6-Mile Depth.” Woods Hole Oceanographic Institution > News & Multimedia > Press Room > News Releases. May 10, 2014.
Available @ http://www.whoi.edu/news-release/Nereus-Lost

Woods Hole Oceanographic Institution. "Underwater Vehicle Nereus." YouTube. June 30, 2009.
Available @ https://www.youtube.com/watch?v=wwdF_2wMRfU