The International Ocean Discovery Program (IODP) continues the 45-year history of accomplishments set by its predecessor programs: the Integrated Ocean Drilling Program (2003–2013), the Ocean Drilling Program (1983–2003), and the Deep Sea Drilling Project (1968–1983). Guided by a new science plan, IODP provides opportunities for international interdisciplinary research teams to conduct transformative and societally relevant research through scientific ocean drilling. The United States has participated in scientific ocean drilling since the program’s inception and continues to do so today through operation of the drilling vessel JOIDES Resolution. Highlights from recent JOIDES Resolution expeditions include investigating subduction and the formation of continental crust, the Asian monsoon systems, and the initiation of rifting and ocean basin formation.
A New IODP Funding Model
At the start of IODP in October 2013, the program implemented a new funding model that continues operations of three drilling platforms. The U.S. National Science Foundation (NSF), the European Consortium for Ocean Research Drilling (ECORD), and Japan’s Ministry of Education, Culture, Sports, Science and Technology (MEXT) now fund and manage their own drilling platform(s) while working together to fulfill the overarching IODP science goals. Each platform provider may then develop international partners who contribute to operating costs of the drilling platform in exchange for berths during expeditions and advisory panel participation.
The JOIDES Resolution is operated by Texas A&M University on behalf of the NSF. In fiscal year (FY) 2015, international partners Brazil, China, Australia/New Zealand, India, South Korea, and ECORD contributed $16.5 million to the operating costs of this vessel. In addition, over the past 2 years, China and India have provided another $12 million to this platform through partial funding of expeditions.
IODP Responds to a Sea Change
In 2013, the NSF asked the National Research Council of the National Academies to undertake a study of ocean sciences to provide guidance on research and facilities priorities for the coming decade. Their report, titled Sea Change: 2015–2025 Decadal Survey of Ocean Sciences [National Research Council, 2015], recognized U.S. participation in IODP as highly relevant in addressing several of the most important issues in ocean science, including ocean and climate variability, sea level change, subseafloor exploration, geohazards, and the formation and evolution of ocean basins. The report also noted the success of the drilling program in building and sustaining long-term international partnerships.
However, Sea Change pointed to the high financial contribution of the United States relative to those of its international partners and urged NSF to pursue more cost-effective partnerships. In addition, Sea Change recommended an immediate 10% reduction in NSF’s contribution to the annual budget for operation of the JOIDES Resolution, followed by further reductions over the next 5 years.
Three actions have been implemented to achieve the recommended 10% cut while continuing the current pace of four expeditions per year on the JOIDES Resolution. The successful reduction of NSF’s contribution in operating the JOIDES Resolution primarily resulted from cost reductions and revenue enhancement since the start of the new program:
- JOIDES Resolution science operations are now conducted by a single entity rather than a consortium of three organizations as in the previous program, thereby reducing costs.
- The JOIDES Resolution Facility Board (JRFB) now organizes ship tracks that minimize transits between drill sites and the nearest port at the beginning and end of an expedition, resulting in significant savings in fuel costs.
- An IODP partner country or consortium can now provide additional funding for specific projects beyond its annual contribution, thereby increasing contributions to JOIDES Resolution operations.
The latter action is achieved via submission of complementary project proposals (CPPs) that are rigorously reviewed by the JRFB advisory panels. This mechanism has proven attractive, given that the JOIDES Resolution has already drilled two such projects, two more with Chinese support are scheduled for 2017, and two CPPs (one led by Australian scientists and one by U.S. scientists) are under review. Thanks to the funding from the two CPPs in 2017, the JRFB expects that the JOIDES Resolution will be able to increase operations in FY 2018 and FY 2019 to five expeditions each year.
The JRFB will be working closely with NSF to examine ways to achieve more reductions in NSF’s contributions to operations of the JOIDES Resolution. Potential options include raising more revenue from international partners, increasing external funding through CPPs, and continuing to find efficiencies in science operations.
Planning for 2016–2017 IODP Expeditions
The JRFB is responsible for annual scheduling and long-term planning of IODP expeditions that will be conducted on the JOIDES Resolution. Locations of completed and upcoming drilling expeditions of the JOIDES Resolution since the start of the new IODP are shown in Figure 1. Expeditions are selected after a rigorous peer-review process of proposals addressing one of the four research themes in the IODP science plan.
For example, several upcoming JOIDES Resolution expeditions will focus on how Earth’s climate responds to elevated levels of atmospheric carbon dioxide. Other expeditions will focus on interactions between the Earth’s crust and mantle, seawater, deep fluids, and the microbial communities that may live deep beneath the seafloor. Still other expeditions will examine tectonic effects, including continental breakup and the formation of oceanic crust. These expeditions are discussed in further detail below.
Climate and Ocean Change
Three upcoming JOIDES Resolution expeditions will focus on how Earth’s climate responds to elevated levels of atmospheric carbon dioxide and how it affects regional patterns of precipitation. IODP Expedition 361 in early 2016 will investigate the interaction between climate and the Agulhas Current off the coast of South Africa, examining how circulation between the Atlantic and Indian Oceans via this current varied during major ocean and climate reorganizations that have occurred over the past 5 million years.
Expedition 363 in late 2016 targets the Indo-Pacific Warm Pool—the largest reservoir of warm surface water on Earth—spanning the western equatorial Pacific to the eastern Indian Ocean. It will investigate the controls on sea surface temperatures and how changes in this region are linked to dynamic events like El Niño and even to the climate variability of the northern Atlantic.
In 2017, Expedition 369 off the southwest corner of Australia will recover cores to chronicle the rise and collapse of the Cretaceous hothouse, a past period of extreme warmth. This will allow scientists to seek out potential links between climate change and the tectonic history of the region.
In 2016, ECORD will sponsor IODP Expedition 364, which will drill 1.5 kilometers into the Chicxulub impact crater off the Yucatan Peninsula in Mexico in collaboration with the International Continental Scientific Drilling Program. Chicxulub, created 65 million years ago by the meteoric impact that is thought to have wiped out the dinosaurs, is the only known impact structure that has been directly linked to a mass extinction event. Studying it will provide insight into the geological structure of the impact crater, the environmental changes leading up to a mass extinction, the subsequent biologic recovery, and the effects of a large impact on the deep subsurface biosphere.
Expedition 360 returns the JOIDES Resolution to the underwater flat-topped peak known as Atlantis Bank, in the Indian Ocean south of Mauritius, in a bid to settle a decades-long debate about the nature of the boundary between the crust and the mantle, known as the Mohorovičić discontinuity, or Moho. This is the first of two expeditions that will drill into the upper mantle at Atlantis Bank. Sampling rock across the boundary will test whether the Moho is a serpentinization front, where mantle rock (peridotite) has been chemically altered, and will further understanding of how mid-ocean ridge basalt is created.
Expedition 366 will take the JOIDES Resolution to the Mariana Convergent Margin, where the Pacific Plate dives underneath the Mariana Plate, creating a subduction zone. The expedition will focus on the exchange of chemicals between the crust and seawater in a subduction zone environment; the role of deep fluids in linking tectonic, thermal, and biogeochemical processes; and the composition of the microbial communities that may live deep beneath the seafloor. The expedition will drill and core at several serpentinite mud volcanoes and install instruments in the boreholes for long-term investigations of these subduction-related subseafloor processes.
China’s Ministry of Science and Technology is partially funding Expeditions 367 and 368 to continue investigating continental breakup and the crustal architecture of the South China Sea. They will test two models for how plates rupture that predict different crustal structures across the transition between oceanic and continental crust. They will also examine the time lag between continental breakup and the formation of oceanic crust and the rates of extension, cooling, and subsidence.
Earth in Motion
The Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE), an important project that uses the Japanese platform Chikyu, continues into the new IODP. Underway since 2007, the goal of this project is to drill and place monitoring instruments into the Nankai plate boundary fault system south of Japan’s largest island, Honshū, which has produced massive earthquakes in the past. Planning continues in Japan for Expedition 365 to install a downhole observatory and for a later expedition to drill a 5-kilometer-deep hole through the plate boundary fault system.
The JOIDES Resolution will complement NanTroSEIZE with two expeditions that also focus on subduction zone processes. Expedition 362 is focused on the 2004 Sumatra seismogenic zone where one of the largest earthquakes ever recorded generated a tsunami that killed roughly 300,000 people in coastal communities around the Indian Ocean. The earthquake occurred where the Indian Plate is being subducted under the Burma Plate, with slip occurring at unexpectedly shallow depths beneath the accretionary prism off the shore of North Sumatra. This is seismic behavior that existing models fail to explain. Expedition 362 will investigate how materials making up the subducting plate drive shallow slip and influence the region’s morphology in order to understand its hazard potential and that of similar seismogenic zones around the world.
In contrast, the northern Hikurangi subduction margin off New Zealand is characterized by slow slip events that recur every 1–2 years. In 2018, the JOIDES Resolution will conduct riserless drilling for a multiphase drilling project that aims to discern the mechanisms behind slow slip events by sampling and monitoring the upper plate and subduction zone.
Long-Term Cruise Track of the JOIDES Resolution
A priority of the JRFB is to use the JOIDES Resolution more efficiently by developing ship tracks that minimize transit times and maximize scientific output relative to time and cost. The JRFB therefore projects the ship’s track 3 to 5 years in advance on the basis of current and anticipated proposals, as well as progress in achieving the goals set forth in the IODP science plan.
At its May 2015 meeting, the JRFB projected that the JOIDES Resolution will follow a path from the southwestern Pacific Ocean, through the Southern Ocean, and into the Atlantic Ocean for opportunities for drilling there starting in FY 2019. It then expects that the drilling vessel will operate in the Atlantic, Mediterranean, Caribbean, and Gulf of Mexico over the next few years. The next IODP proposal submission deadline is 1 April 2016; guidelines can be found on the IODP’s website.