The Deep-Sea Scientific Drilling Vessel Chikyu, operated by Japan Agency for Marine-Earth Science and Technology (JAMSTEC: Hiroyuki Yamato, President) has completed the International Ocean Discovery Program (IODP)※1 Expedition 405: Tracking Tsunamigenic Slip Across the Japan Trench (JTRACK), the final expedition of IODP on 20 December (Fri) 2024, having achieved its objectives. Throughout this expedition, data and samples were obtained to elucidate the process of stress accumulation and strength recovery of the source fault after a massive earthquake, and long-term borehole monitoring systems were successfully installed to elucidate the hydraulic structure of the fault.
We will continue to study the strength recovery and stress accumulation process of the fault based on the data and samples obtained during this expedition.
International Ocean Discovery Program (IODP)
A multinational scientific research cooperation project launched in October 2013. The project aims to elucidate global environmental changes, the Earth's internal structure, and life cycles in the Earth's crust by drilling the deep ocean floor using drilling vessels provided by Japan (Chikyu), the United States (JOIDES Resolution), and Europe (Mission-Specific Platforms). The project ended in September 2024.
JFAST
IODP Expedition 343, “Japan Trench Fast Drilling Project (JFAST),” which was conducted in 2012 after the Tohoku Earthquake 2011.
Logging-While-Drilling
Logging-While-Drilling is a survey in which various types of geophysical measurement sensors are mounted near the drill bit at the bottom of the drill string to measure the physical properties of the formation at the same time as drilling, and transmit the data to the vessel in real time.
Figure 1: Survey area map
Figure 2: Drilling process
Photo 1: Underwater TV camera image of the thermometer installation in the JFAST borehole on September 12.
For this study
(For IODP and this expedition)
General Affairs Group, Planning and Coordination Department,
Institute for Marine-Earth Exploration and Engineering (MarE3)
For press release