Now Sailing: Amundsen Sea West Antarctic Ice Sheet History

The recent (past several million years) history of climatic and oceanographic changes as seen through influences on the Western Antarctic Ice Sheet (WAIS) will be investigated aboard the JOIDES Resolution by drilling sites on the continental shelf and rise of the Amundsen Sea. This expedition explores the relationship of the Paleogene-to-Holocene glacial history of Western Antarctica with global records of ice volume and other proxies of air/sea average temperature from the same period.

Also Sailing: NanTroSEIZE Deep Riser Drilling

Chikyu continues the 4th riser expedition of the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE). The current effort, Nankai Seismogenic / Slow Slip Megathrust, will attempt to deepen hole C0002, currently drilled to 3000 meters below the seafloor (mbsf), to 5200 mbsf in order to encounter the primary megathrust fault of this subduction system. This expedition will be the culmination of 10 years of IODP NanTroSEIZE deep drilling efforts to reach the plate interface fault system at seismogenic / slow slip depths.

Recently Completed (December 2018): Return to Hole U1503A (South China Sea)

In this three-week follow-up to Expedition 368, JOIDES Resolution returned to core a critical site that documents the rapid transition from continental break-up to formation of normal oceanic crust. This operation was previously abandoned due to a breakdown in the JR draw-works.

Recently Completed (July 2018): Brothers Arc Flux

This JR expedition to the Brothers submarine volcano in the southern part of the Kermadec Arc explored this magma-derived hydrothermal system, including fluid-rock interactions, the distribution of metals/metalloids and their pathway from depth to the seafloor, and the nature of microbial life in this extreme environment.

Recently Completed (May 2018): Hikurangi Subduction Margin

This JR expedition to study slow slip events (SSE - episodic movements of the plate interface) along the northern Hikurangi subduction margin off New Zealand's North Island retrieved samples from the subducting plate and from primary thrust faults in the accretionary wedge. Borehole observatories that will continue to monitor the slip source area were installed at two sites in the frontal thrust and upper plate.

Recently Completed (February 2018): NanTroSEIZE Front Thrust Long-Term Borehole Monitoring System

This expedition aboard Chikyu installed a long-term borehole monitoring system (LTBMS) in NanTroSEIZE hole C0006, complementing two existing nearby subseafloor observatories as part of the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE). The LTBMS will connect to Japan's DONET undersea cabled network, sending pressure, strain, and seismic data to the mainland in real time. 

Recently Completed (March 2018): Ross Sea West Antarctic Ice Sheet History

This JR expedition recovered sediment cores and log data from drill sites in the eastern Ross Sea offshore western Antarctica to help understand the evolution of the Western Antarctic Ice Sheet (WAIS) over the past 20 million years, including its response to changes in ocean heat flux. This expedition has implications for ice sheet stability and assessing far-field sea-level rise from the current warming trend observed in the Southern Ocean over the past several decades.

Recently Completed (January 2018): Creeping Gas Hydrate Slides and Hikurangi LWD

This JR expedition offshore New Zealand collected logging-while-drilling (LWD) data and core samples that will be used to explore the relationship between gas hydrate deposits and submarine landslides, a significant geohazard,   Additionally, Expedition 372 carried out advance work for the upcoming expedition to the Hikurangi subduction zone on New Zealand's eastern boundary by collecting LWD data in advance of coring and downhole measurements.  

Recently Completed (December 2017): Corinth Active Rift Development

This expedition recovered sedimentary sequences at three sites in the Gulf of Corinth using the mission-specific platform Fugro Synergy.  Further study of these sediment cores will help understand how continental rifting leads to the formation of ocean basins, and will also provide details about the fault system associated with the active rift, its history, and current geohazard potential.  press release  *  blog  *  reports

Recently Completed (November 2017): Australia Cretaceous Climate and Tectonics

This JR expedition off southwest Australia recovered samples recovered from the Naturaliste Plateau and adjacent sedimentary Mentelle Basin to study the formation and collapse of the Cretaceous hothouse Earth, how ocean anoxic events are related to carbon perturbations, deep water formation during the Cretaceous, the influence of ocean circulation gateways around the Australian continent, and details of how plate motions have affected deposition of sediments in this area. Reports

Recently Completed (September 2017): Tasman Frontier Subduction Initiation and Paleogene Climate

In this JOIDES Resolution expedition, six seafloor sites in the complex region of the Tasman Sea between Australia and New Zealand, sometimes referred to as Zealandia, were cored and logged to infer the timing and geometry of subduction initiation along the Tonga Kermadec Arc approximately 50 million years ago, which is the largest subduction initiation event identified in plate tectonics. The recovered sediments will provide constraints on how the beginning of subduction here changed ocean conditions and connections between the polar ocean to the south and more tropical regions to the north.