Extreme underwater pressure could have possibly led a multimillion dollar hybrid robotic deep-sea vehicle to its demise in the waters of New Zealand.
The last whereabouts of a Hybrid Remotely Operated Vehicle named Nereus was detected 6.2 miles underwater in the Kermadec Trench northeast of New Zealand. It was still in the middle of its 40-day expedition on board Thomas G. Thompson research vessel in a bid to roll out a systematic study on deep-ocean trench, the first in its kind.
On its 30th day, the researchers aboard the vessel lost contact with Nereus seven hours into a planned nine-hour dive in the hadal region, or the demarcation of the deepest trenches in the ocean. After failed attempts in its standard emergency recovery protocols, researchers found debris of the eight-million dollar underwater probe surfacing in the water near its diving site.
They deduced the underwater pressure could have reached a tremendous 16,000 pounds per square inch that could have prompted the implosion. Nereus was designed to withstand only 15,000 pounds of pressure.
"Nereus helped us explore places we've never seen before and ask questions we never thought to ask," said chief scientist Timothy Shank, a Deep Submergence Lab at the Woods Hole Oceanographic Institution (WHOI) biologist and the project lead of the Hadal Ecosystems Study project, in which Nereus was involved.
"It was a one-of-a-kind vehicle that even during its brief life, brought us amazing insights into the unexplored deep ocean, addressing some of the most fundamental scientific problems of our time about life on Earth," Shank added.
When WHOI built Nereus in 2008, its primary purpose is to explore Challenger Deep, the world's deepest part of the ocean located near the Marianas Islands in west Pacific that is around seven miles deep. It turned out to be Nereus' deepest and most recognized dive, as it survived the 6.8-mile lunge in 10 grueling hours, and even came back with the specimens of the rarest marine life thriving in the ocean's bottoms.
Nereus was the third to reach the Earth's lowest point, next to the first manned expedition of Bathyscaphe Trieste in 1960, and Kaikō, the first unmanned robotic sea-probe from Japan in 1995.
Aptly named after a mythical Greek god with a fish tail and a man's torso, Nereus is a hybrid vehicle. It was designed to either work as an autonomous underwater vehicle or as a remotely operated vehicle should Nereus spot something interesting that would require hands-on probing of the researchers.
