The CHIKYU is operated by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) in partnership with the Integrated Ocean Drilling Program. The expedition began with drilling operations at the Kumano Basin, off the Kii Peninsula on May 10, 2009.
Expedition 319 marks the first riser drilling in the history of the scientific ocean drilling program, and the first subseafloor observatory operations for NanTroSEIZE. The expedition was led by four Co-Chief Scientists: Eiichiro Araki, Research Scientist of JAMSTEC; Timothy Byrne, Professor of the University of Connecticut, USA; Lisa McNeill of the University of Southampton, UK; and Demian Saffer, Associate Professor of Geosciences at The Pennsylvania State University, and was joined by scientists from eight countries.
Expedition 319 conducted drilling operations at three drill sites in the Nankai Trough. At the first Site C0009, located directly above the seismogenic zone where great earthquakes occur, scientists conducted the first riser drilling in IODP history and successfully drilled down to a depth of 1,603.7 meters beneath the sea floor. Riser-based drilling allowed the scientists to conduct several scientific operations unprecedented in IODP, including 12 successful measurements of stress and pore fluid pressure in the subsurface using the dynamic formation testing tool, a two ship seismic experiment using a dense seismic array in the borehole, real-time mud gas analysis, and laboratory analyses of drill cuttings that are generated as the drill bit penetrates through the formation. In addition, 57.87 meters of core sample (a cylindrical geological sample) were obtained from depths between 1,510 and 1,593.9 meters below the seafloor. The scientific party developed several new techniques for analyzing these materials, which will be essential for future riser-based drilling.
At a second borehole (Site C0010), drilling crossed one of the major faults in the plate boundary, known as the mega-splay fault, at a depth of about 400 meters below the seafloor. This fault is a prime candidate for tsunami generation, and may have slipped in historical great earthquakes. During the drilling operation, scientists documented rock physical properties and gained information about stresses in the formation. The borehole was then cased and utilized for observatory operations for future long-term borehole monitoring. These included lowering of test instruments, as well as emplacement of a temporary sensor package that will monitor conditions in the fault zone in the next few years.
The new data from Expedition 319 indicate that the stresses in the upper plate reflect the forces acting on the earthquake generating fault zones below. The direction of the maximum stresses follows the direction of tectonic plate motion in most of the region, but rotates drastically in a very narrow region above the mega-splay fault. In addition, the rock units, and in particular the ages of the rocks obtained by examining microfossils and the sediment types observed in the drill cuttings, provide new constraints on the geologic history of the major fault zone and its activity level.
The CHIKYU is now berthed at the Port of Yokkaichi, where it is preparing for IODP Expedition 322 scheduled to sail on Sept. 4. Operations will include core sampling and logging for all layers in the formation, with an aim to better understand the initial state of geological input materials before they are entering the seismogenic zone.
The Integrated Ocean Drilling Program (IODP) is an international marine research drilling program dedicated to advancing scientific understanding of Earth by monitoring, sampling, and instrumenting subseafloor environments. Through multiple platforms, preeminent scientists explore IODP principal themes: the deep biosphere, environmental change, and solid Earth cycles. IODP has operated since October 2003, funded jointly by the Japan Ministry of Education, Culture, Sports, Science and Technology and the U.S. National Science Foundation. 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. http://www.iodp.org
To learn more about NanTroSEIZE, visit http://www.jamstec.go.jp/chikyu/eng/Expedition/NantroSEIZE/index.html or access the NanTroSEIZE media kit at http://www.iodp.org/NanTroSEIZE-Media-Kit/3
Find more information on riser drilling at http://www.iodp.org/riser-vessel/.Contacts:
Raesah Et'Tawil | EurekAlert!
Fossil coral reefs show sea level rose in bursts during last warming
19.10.2017 | Rice University
NASA finds newly formed tropical storm lan over open waters
17.10.2017 | NASA/Goddard Space Flight Center
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
19.10.2017 | Materials Sciences
19.10.2017 | Materials Sciences
19.10.2017 | Physics and Astronomy