May 13, 2014 5:22 PM by ABC News/National Post
An unmanned remote-controlled research sub exploring some of the deepest depths of the Pacific Ocean has been lost during a dive some 9,990 metres underwater.
A team found parts of the sub floating on the surface.
The Woods Hole Oceanographic Institution says a portion of the Hybrid Remotely Operated Vehicle Nereus likely suffered a "catastrophic implosion" during its dive to the Kermadec Trench on Friday "under pressure as great as 16,000 pounds per square inch."
The sub was being operated as part of the Hadal Ecosystems Studies (HADES) Program funded by the U.S. National Science Foundation.
The researchers lost contact with the sub seven hours into what was set to be a nine-hour mission in the "deepest extent" of the trench.
The hadal zone is the name given to the deepest depths of the ocean, named for the underworld of Greek mythology. The Kermadec Trench is the fifth-deepest in the world, off the coast of New Zealand.
Nereus, which was built in 2008, was one of only four submersibles that have completed a mission to the ocean's deepest point - Challenger Deep in the Mariana Trench.
Woods Hole science editor Ken Kostel called the loss of Nereus a "body blow" but the team will continue to learn more about "a place that does not give up its secrets easily."
"Nereus helped us explore places we've never seen before and ask questions we never thought to ask," chief scientist Timothy Shank said in the release.
"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."