The Integrated Ocean Drilling Program

For nearly 50 years, scientific ocean drilling initiatives from the Deep Sea Drilling Project (DSDP) and Ocean Drilling Program (ODP) to the Integrated Ocean Drilling Program (IODP) have revolutionised our view of Earth history and global processes. These research programmes are widely considered to be models for international cooperation in multidisciplinary research and technological development.

The Integrated Ocean Drilling Program started operating in October 2003, with the support of the US (United States) National Science Foundation and Japan’s Ministry of Education, Culture, Sports, Science, and Technology. Additional support is provided by the 17-member European Consortium for Ocean Research Drilling (ECORD), China’s Ministry of Science and Technology, and the Republic of Korea. Negotiations with Australia, New Zealand, and India are underway to expand IODP’s international membership. Its growth is a key part of the Program’s strategy.

Investigating Climate Change

At the heart of IODP is the Initial Science Plan (ISP), the fundamental blueprint to the scientific and technical objectives of IODP. Scientific emphasis is placed on three areas of investigation:

1) Environmental Change, Processes, and Effects: To understand global change, scientists must determine the mechanisms that drive climate events. IODP is drilling in equatorial (see picture) and polar regions to acquire geological samples that yield critical information about past extreme climates. Such samples provide indispensable context for evaluating contemporary inputs to the environment, and creating climate models that aid in projecting future climate conditions.

2) The Deep Biosphere and Subseafloor Ocean: The legacy Ocean Drilling Program provided the first evidence of abundant, diverse microbial activity deep within ocean crust. This encouraged microbiologists, biogeochemists, and geologists to expand subseafloor explorations of sediment and rock lithology, organic carbon content, rates of sediment accumulation and depth and how they influence the ecosystem. Global mapping of subseafloor biological communities is critical to fully understanding this ecosystem.

3) Solid Earth Cycles and Geodynamics: Continental break-up and its role in sedimentary basin formation, volcanism, the formation of rifted margins and oceanic plateaus, seafloor spreading, and the generation of earthquakes and tsunamis comprise this major area of focus. Scientists aim to learn more about the history and mechanisms of these colossal events and what the data may indicate to future generations of Earth dwellers.

Global expeditions

During the first phase of IODP operations, four drilling expeditions focused on climate change investigations. Perhaps the most significant of these was the Arctic Coring Expedition (ACEX) near the North Pole. The expedition recovered the first extensive series of sediments that yielded prehistoric climate records of the Arctic Ocean.

Navigating thick and relentless ice floes, the research team strategically managed three icebreakers, one equipped with a drill rig. A complete geological sediment record was recovered from the Lomonosov Ridge, in water approximately 1,000 metres deep. These records provided evidence from the time when the last massive amounts of greenhouse gases were released into the Earth’s atmosphere – a period calculated to have occurred 55 million years ago, known as the Paleocene/Eocene thermal maximum (PETM). The research also shows that at that time the Arctic climate was extremely warm and unusually wet, and that the Arctic Ocean was ice-free up to 46 million years ago.

Multiple platforms for subseafloor investigations:

• A riserless platform, provided by the US, is managed by an alliance of three institutions (the Consortium for Ocean Leadership, Texas A & M University, and Lamont-Doherty Earth Observatory of Columbia University). The Texas-based Gulf Coast Core Repository archives sediment cores retrieved by any of the IODP platforms in the following regions: the Pacific Ocean (Pacific plate east of western boundary); the Caribbean Sea and Gulf of Mexico; the Southern Oceans (S of 60º except Kerguelan Plateau).

• Riser platform operations are conducted aboard the Chikyu, a state-of-the-art research drilling vessel provided by Japan and managed by Japan’s Centre for Deep Earth Exploration (CDEX). Drilling operations are performed in cooperation with the Centre for Advanced Marine Core Research at Kochi University, which contributes to sediment core processing and which archives cores collected from the Pacific Ocean (west of western boundary of Pacific plate); the Indian Ocean (N of 60ºS), all of the Kerguelan Plateau and the Bering Sea.

• Mission-specific drilling operations are conducted by ECORD (ECORD Science Operator - ESO), a collaboration between the British Geological Survey, the University of Bremen–Germany, and the European Petrophysics Consortium. ESO works in cooperation with the Bremen Core Repository, which archives cores from the Atlantic and Arctic Oceans, north of the Bering Strait.

Twice a year IODP accepts and reviews drilling proposals. Proposals originate from science proponents, who are often faculty members of prominent academic institutions; scientists who specialise in geology, geophysics, sedimentology, paleontology, paleoceanography, seismology or microbiology. Once a proposal is submitted to IODP, it is carefully nurtured and evaluated to ensure its smooth movement through a Science Advisory Structure, a group of oversight panels and committees that nurture and enhance proposals until they can be ranked and prioritised for scheduling.

W: www.iodp.org