Chikyu- Successful Start to Drilling to the Earthquake Zone

Shimizu, Japan, 23 August 2010 –Scientists have successfully started drilling a hole to the earthquake zone more than 1,900 meters beneath the sea off the eastern coast of Japan.

Aboard the scientific drilling vessel “Chikyu” scientists have successfully begun drilling a hole that they anticipate will provide insights in the causes of earthquakes and tsunami.  The upper part of this hole, extending more than 870 meters below the seafloor, has been fitted with casing pipes and a well head system on the sea bed as a first step in the -“ultra-deep”- drilling effort to reach the seismogenic zone, the depth region where large earthquakes and tsunami are generated. This hole will be re-visited in subsequent expeditions and is targeted to reach an ultimate depth of 5-7 km below the seafloor.

The Japan Agency for Marine-Earth Science and Technology (JAMSTEC) announced the completion of IODP Expedition 326 as the vessel returned to Shimizu Port, on 20th August after 37 days offshore operations.

“We showed that Chikyu can complete complex operations under strong Kuroshio ocean current conditions, and that bodes well for future plans to deepen this borehole,” commented Dr. Harold Tobin, one of the co-chief scientists on this research project.

Expeditions in this area have face difficult conditions from the strong oceanic currents above the research sites. The Kuroshio current and the weather create challenges to keeping the drilling vessel relatively steady as the scientific drilling equipment are operated from the Chikyu’s rig floor.

The Nankai Trough is an area off the southeast coast of Japan and a source of great earthquakes caused by the Philippine Sea Plate being forced beneath the Eurasian Plate. This area is known as one of the most active earthquake zones on the planet. The IODP Nankai Trough Seismogenic Zone Experiment was designed to drill into the tectonic plate faults, which are believed to cause earthquakes and tsunami, in order to sample rock and place instruments inside the earthquake fault.

The Integrated Ocean Drilling Program (IODP) is an international marine research program funded jointly by the U.S. National Science Foundation and Japan Ministry of Education, Culture, Sports, Science and Technology. Additional support is provided by the 17-member European Consortium of Ocean Research Drilling, the People's Republic of China, the Republic of Korea, Australia, India, and New Zealand. www.iodp.org 

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