Researchers will survey the mechanism behind what caused the 2011 Great East Japan Earthquake in a new deep-sea drilling project.

They hope to shed light on what happened underground as scientists have not been able to answer questions like why the magnitude 9.0 temblor occurred in a different location than expected.

Deep-sea drilling vessel Chikyu will drill about a kilometer into the ocean floor off the Tohoku region in northeastern Japan at a depth of about 7,000 meters to collect stratum samples.

Researchers are aiming to find out what happened at the fault zone in March 2011 and what is happening there now.

S/ Ujiie Kohtaro, Project co-chief / I think we will be able to tell whether the plate is starting to accumulate strain toward the next earthquake or whether it is still in a state of having released the strain.

Chikyu was set to depart Shimizu port in Shizuoka for Pacific waters off northeastern Japan on September 6 for the survey scheduled through December.

The expedition is a project of the Japan Agency for Marine-Earth Science and Technology.