An international effort to drill into the floor of the Indian Ocean in an effort to reach below the Earth’s crust for the first has come up short.
The expedition on the ship, the Joides Resolution, had set out to drill down to 4,265 feet in a stretch of ocean floor off Africa known as the Atlantis Bank gabbroic massif. Gabbro is an intrusive igneous rock that forms when magma is trapped beneath Earth's surface and cools slowly.
But the researchers, who had been on the expedition since Nov. 30, were only able to drill down to 2,588 feet, according to a blog post from one of the onboard education and outreach officer Lucas Kavanagh.
“We may not have made it to our goal of 1300 m, but we did drill the deepest ever single-leg hole into hard rock (789 m), which is currently the 5th deepest ever drilled into the hard ocean crust,” Kavanagh, who works for a Canadian charity devoted to providing hands on science experiences to young people and hosts Double Blind, a science news and discussion podcast, wrote.” “We also obtained both the longest (2.85 m) and widest (18 cm) single pieces of hard rock ever recovered by the International Ocean Discovery Program and its predecessors.”
The researchers, who have long said it would take several expeditions to cut through the Earth’s crust, are hopeful of returning to this site in the near future.
The short-term goal of the project is to recover enough gabbros and crust-mantle transition to understand the processes that creates mid-ocean ridge basalt. The project also aims “to resolve the controversy as to whether the boundary between Earth's mantle and crust, or Moho, at slow spreading ridges can be a serpentinization front.”