History of Scientific Ocean Drilling

1961: Project MoHole

Project Mohole, funded by the U.S. National Science Foundation (NSF), was an attempt to drill through the geological boundary identified by an abrupt acoustic change in rock physical parameters (Mohorovičić discontinuity) that marks the transition from thin oceanic crust to the mantle, Earth's main interior layer. In 1961, using the first rudimentary dynamic positioning system on the drilling barge Cuss I, Project Mohole successfully recovered sediment and crustal rock, which demonstrated the feasibility of scientific ocean drilling to study Earth’s subseafloor geology in the open ocean.

1966–1983: Deep Sea Drilling Project (DSDP)

The Deep Sea Drilling Project (DSDP), which started operations in 1968, utilized the drillship Glomar Challenger to conduct 96 expeditions recovering more than 97 km of core. This project initially was driven by a partnership of United States research institutions and universities, which included Lamont-Doherty Earth Observatory, the Institute for Marine Sciences at the University of Miami, Scripps Institution of Oceanography, and Woods Hole Oceanographic Institution, and was funded by NSF. DSDP became an international program in 1975 with the addition of Germany, Japan, the United Kingdom, France, and the Soviet Union. Scripps Institution of Oceanography was the Glomar Challenger science operator.

Because scientific ocean drilling was a new endeavor, it is not surprising that significant advances in coring tools and operational techniques occurred during DSDP, including initial design and testing of tools that became routine in scientific drilling. The first use of a re-entry system was developed in 1970, allowing coring bits to be changed as they wore out, resulting in deeper penetration below the seafloor. In 1979, DSDP deployed the Hydraulic Piston Corer (HPC), an earlier version of the Advance Piston Corer (APC), which revolutionized scientific ocean drilling. The HPC and APC allowed recovery of undisturbed sequences of unlithified sediments that made detailed, high-resolution paleoceanographic studies possible. This development was followed by deployment of the Extended Core Barrel in 1982, which brought improved recovery in sediments that were not well-recovered by either rotary or piston coring.

1983–2003: Ocean Drilling Program (ODP)

In 1985, the U.S.-operated drillship JOIDES Resolution began operations for the Ocean Drilling Program (ODP). ODP was an international partnership to explore and study the composition and structure of the Earth’s subseafloor. Funding was provided by the United States, a Pacific consortium (Australia, Canada, Chinese Taipei, and South Korea), a European consortium (Belgium, Denmark, Finland, Iceland, Ireland, Italy, The Netherlands, Norway, Portugal, Spain, Sweden, and Switzerland), France, Germany, the United Kingdom, China, and Japan. While DSDP was exploratory in nature, scientific ocean drilling had matured to a hypothesis-driven peer-reviewed proposal system in ODP, based on community-driven science plans.

The JOIDES Resolution conducted 110 expeditions for ODP, occupying 2,000 holes and recovering 36,365 cores—nearly 223 kilometers of sediment and rock. More than 2,500 scientists representing more than 220 institutions sailed on ODP legs.

ODP traversed the world’s oceans from the Arctic to the Antarctic, collecting sediment and rock samples, recording downhole geophysical and geochemical information, and establishing long-term borehole observatories to monitor earthquakes, tsunamis, and fluid flow in ocean sediments and crust. ODP studies led to a better understanding of plate tectonic processes, Earth’s crustal structure and composition, environmental conditions in ancient oceans, and climate change. Highlights of ODP drilling are compiled in two ODP greatest hits volumes.

2003–2013: Integrated Ocean Drilling Program (IODP)

From 2003 through 2013, the Integrated Ocean Drilling Program continued the international exploration of subseafloor environments started by DSDP and ODP following the broad themes described in the initial science plan: “Earth, Oceans and Life: Scientific Investigations of the Earth System Using Multiple Drilling Platforms and New Technologies.” The Integrated Ocean Drilling Program expanded the capabilities of scientific ocean drilling using multiple drilling platforms—a riserless drilling vessel, a riser drilling vessel, and mission-specific platforms— operated by three implementing organizations (IOs) to achieve the science plan goals.

The riserless drilling vessel JOIDES Resolution, which was operated by the U.S. Implementing Organization (USIO), allowed the Integrated Ocean Drilling Program to continue operation of a globally ranging drillship that allowed the disciplinary breadth that was characteristic of DSDP and ODP. The riser drilling vessel Chikyu, operated by Japan’s Center for Deep Earth Exploration (CDEX), provided deep drilling capabilities. Mission-specific platforms, operated by the European Consortium for Ocean Research Drilling (ECORD) Science Operator (ESO), allowed drilling in environments unsuitable for either JOIDES Resolution or the Chikyu, such as in shallow water and in climatically sensitive or ice-covered regions. These platforms were used to reach new areas of the global subsurface during 54 expeditions, recovering 66.3 km of core.

Integration and oversight of platform operations and proposal peer review was provided by a nonprofit central management office, Integrated Ocean Drilling Program Management International (IODP-MI), funded by the partner nations. The USIO comprised the Consortium for Ocean Leadership, Inc. (Ocean Leadership), and its partners, Lamont-Doherty Earth Observatory (LDEO) of Columbia University and Texas A&M University (TAMU). As the prime contractor, Ocean Leadership had overall project oversight and subcontracted LDEO to provide downhole logging services, and TAMU as the JOIDES Resolution science operator. Operation of the JOIDES Resolution was responsible for 64% of the expeditions and 86% of the core recovery during the Integrated Ocean Drilling Program.

2013–2024: International Ocean Discovery Program (IODP)

The International Ocean Discovery Program (IODP) was the fourth generation of international scientific ocean drilling, guided by the IODP science plan, “Illuminating Earth’s Past, Present, and Future.” IODP depended on the same three facilities from the Integrated Ocean Drilling Program, but without a central management office. Instead, funding came directly from the platform providers—NSF for the JOIDES Resolution, MEXT (Japan Ministry of Education, Culture, Sports, Science, and Technology) for the Chikyu, and ECORD for MSPs—with financial contributions from up to five additional partner agencies. Together, these agencies represented up to 26 nations, at its maximum, whose scientists were selected to staff IODP research expeditions conducted throughout the world’s oceans. Scientific participation on expeditions and seats on the advisory panels was based on memorandums of understanding (MOUs) among the partners. Individual scientist participation was funded by their IODP Program Member Offices.

The JOIDES Resolution was managed and operated for NSF by the JOIDES Resolution Science Operator (JRSO), Texas A&M University. The JRSO was formalized as the implementing organization for IODP in 2014.

The Chikyu was operated for MEXT by Japan’s Center for Deep Earth Exploration (CDEX), which was established within the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) in October 2002. In 2019, JAMSTEC merged CDEX with its Marine Technology and Engineering Center (MARITEC) to create a new department, the Institute of Marine-Earth Exploration and Engineering (MarE3), which managed Chikyu.

The ECORD Science Operator (ESO), the same operator that was established in 2003, was the implementing organization for mission-specific platform expeditions.

During IODP, JOIDES Resolution, Chikyu, and ESO MSPs completed 58 expeditions, recovering 98.9 km of core. The JOIDES Resolution was used to complete the majority of IODP expeditions (79%) and recovered 94% of core. An IODP achievements report is currently being developed by a community working group.

Post-2024 Scientific Ocean Drilling

The international science community produced a guiding document for the next phase of scientific ocean drilling, “Exploring the Earth by Scientific Ocean Drilling: 2050 Science Framework.” This Framework comprises seven broad Strategic Objectives that focus on various interconnections within the Earth system, including planetary habitability, life cycles of tectonic plates, Earth’s climate system, feedbacks, tipping points, cycles of energy and matter, and natural hazards. Five societally important Flagship Initiatives are also identified around goals such as ground-truthing future climate change, probing the deep Earth, natural hazard assessment, diagnosing ocean health, and exploring the origins of life.

In the U.S., the JOIDES Resolution completed its last scientific ocean drilling expedition at the end of IODP in August of 2024. During the 39-year history of ODP, Integrated Ocean Drilling Program, and IODP, the JOIDES Resolution was used to conduct 192 expeditions, recovering more than 373 km of core. Without the JOIDES Resolution, the U.S. will transition to a mission-specific platform operation, and NSF has awarded a TAMU and LDEO partnership a cooperative agreement to run the U.S.-based Scientific Ocean Drilling Coordination Office (SODCO), to work with the U.S. science community to implement expeditions.

ECORD and Japan have formed a collaboration called the International Ocean Drilling Programme (IODP3), which will provide two types of facilities—the Chikyu operated by JAMSTEC, and MSPs managed by ESO—to address scientific ocean drilling research objectives. China recently completed a new drilling vessel, Meng Xiang, which will also address ocean drilling science.