British boffins set off on journey to center of the Earth

British have embarked on a mission to study a gigantic hole in the Atlantic seabed -- an enigma that defies traditional geophysical theory and will give researchers an unprecedented look into the center of the Earth.

The 12-person team left the Canary Islands on Monday with a new high-tech vessel and a robotic device named Toby that will dig up rock samples at the bottom of the crater and film what it sees.

The hole is about 5,000m under the surface of the Atlantic and located halfway between Tenerife and Barbados. It has a diameter of 3,000m to 4,000m.

The mysterious orifice is in an undersea mountain range, the kind of structure believed to form when Atlantic tectonic plates separate and volcanic lava surges upward to fill the gap in the Earth's crust.

But that did not happen this time. Instead, the hole exposes the mantle, the material that makes up Earth's interior, said British geophysicist Roger Searle of Durham University, one of the lead researchers.

"We do not know why that is," Searle said in an interview on Monday before setting sail on the RRS James Cook for the six-week mission. "Because of this gap we can see directly into the Earth's mantle."

He said the first-of-its-kind study aims to provide insight on everything from the chemistry of oceans to the mechanisms of how the Earth behaves under so much water.

The robotic device will land on the bottom of the crater -- measuring its depth is another unknown the team hopes to resolve -- deploy a drill and dig into the mantle to bring back samples.

The project is being financed by Britain's National Environment Research Council and the Department of trade and Industry's Large Scientific Facilities Fund.