VOL. 29, NO. 3–4 | MARCH-APRIL 2019 Holes in the Bottom of the Sea: History, Revolutions, and Future Opportunities Holes in the Bottom of the Sea: History, Revolutions, and Future Opportunities Suzanne OConnell, Professor of Earth & Environmental Sciences, Wesleyan University, Middletown, Connecticut 06459, USA, [email protected] ABSTRACT about plate tectonics, ocean chemistry, (Scripps Institution of Oceanography No other international scientific col- evolution, life in harsh environments, [SIO]) and Harry Hess (Princeton laboration has contributed as much to our and climate change. University), both AMSOC members, knowledge of Earth processes as scientific Scientists from across the world have proposed to drill a deep hole to sample ocean drilling (SOD). These contributions benefited from and contributed to the pro- Earth’s mantle below a zone of seismic include geophysical surveys, core sam- gram. Geophysical site survey data, cores, velocity change, the Mohorovicic ples, borehole well logs, and sub-seafloor and associated information are available to Discontinuity (Moho): “Project Mohole.” observatories. After more than half a the global scientific community to study The National Science Foundation (NSF) century, involving thousands of scientists and sample. More than 1000 international may have been in favor of the project, from around the world, SOD has been scientists, ranging in age from early career because the 1957 International Union of instrumental in developing three geosci- to retired, are proponents on active propos- Geodesy and Geophysics Resolution 11 ence revolutions: (1) plate tectonics, als for upcoming drilling. recommended that the Moho be drilled. (2) paleoceanography, and (3) the deep This article, by no means comprehen- The Soviet Union said they had the equip- marine biosphere. Without SOD, it is sive, highlights parts of the history and a ment and were looking for a place to drill unlikely that our current understanding few major discoveries of SOD. More (Bascom, 1961). They had just launched of Earth processes could have developed. complete histories are available in Ocean the Sputnik satellite. Their technological Building upon prior scientific results, Drilling: Accomplishments and Challenges advance alarmed many Americans the current science plan is guided by four (National Research Council, 2011), Earth and spurred investment in U.S. science interlinked themes: Planetary Dynamics, and Life Processes Discovered from and technology. Climate and Ocean Change, Biosphere Subseafloor Environments: A Decade of Despite the difficulties of SOD, Frontiers, and Earth in Motion. SOD has Science Achieved by the Integrated Ocean AMSOC, with NSF funding, took on the also been a leader in international collabo- Drilling Program (IODP) (Stein et al., challenge. Many technological improve- rations and the open sharing of samples, 2014), and Koppers et al. (2019). GSA Data ments were necessary for such a project: data, and information. Results from SOD Repository Table S1 (see footnote 1) a drilling platform that could hold station expeditions are open access and available provides URLs to detailed, preliminary in deep water and under different wave online. Almost 2.5 million samples have information for all SOD expeditions and and wind conditions (dynamic position- been taken from over 360 km of core legs, including co-chief scientists, sites ing), a way to retrieve cores through drill located in three repositories. Today about cored, and year. pipe so that the drill pipe could stay in half the members of scientific teams, place, and a sturdy drill bit that could including co-chief scientists, are women. HISTORY operate for days, even weeks. The first This program is needed in the future for drilling was accomplished in 1961 with the geoscientists to continue exploring our Pre-JOIDES (Joint Oceanographic barge, CUSS I (Continental, Union, Shell, planet to understand how it functions and Institutions for Deep Earth Sampling) and Superior). Unfortunately, after a prom- to create predictive models. SOD may be said to have originated ising start, organizational difficulties, and with the International Geophysical Year loss of political support, Project Mohole, INTRODUCTION (1957–1958), and an organization with the deemed too expensive, was abandoned in Scientific ocean drilling (SOD) cele- unlikely name American Miscellaneous 1966 (Hsü, 1992). brated its 50th birthday in 2018. As of Society (AMSOC). AMSOC included men December 2018, 283 expeditions (formerly at pivotal positions at oceanographic insti- The Glomar Challenger called legs) have been completed and tutions, oil companies, the Office of Naval Not everyone agreed that drilling a >1600 sites have been drilled (see Fig. S1 Research, and the United States Geological single deep hole in igneous rock was the in the GSA Data Repository1). These sites Survey. Bascom (1961) provides details best initial SOD research objective. In represent <0.0005% of the ocean floor, about AMSOC and the development of 1962, Cesare Emiliani (University of yet have provided essential information their discussions about SOD. Walter Munk Miami) proposed that a drilling vessel be GSA Today, v. 29, https://doi.org/10.1130/GSATG380A.1. Copyright 2019, The Geological Society of America. CC-BY-NC. 1 GSA Data Repository item 2019051, Table S1 and Figures S1–S7, is available online at www.geosociety.org/datarepository/2019. deployed to core continuously through deep-sea sediment (project LOCO, LOng COres). Maurice Ewing (Columbia University, also a member of AMSOC) supported obtaining multiple long cores, stating, “The entire record of terrestrial conditions from the beginning of the ocean is there in the most undisturbed form it is possible to find anywhere—and the dream of my life is to punch that hole 2000 feet deep and bring the contents to the lab to study them” (Gray, 1956). Thus, simultaneously with Project Mohole, a different kind of program was planned. Five U.S. oceanographic institu- tions established JOIDES (Joint Ocean- ographic Institutions for Deep Earth Figure 1. Multichannel Seismic Line 1027 in Baltimore Canyon, used to locate the best sites (902, Sampling). In 1965, using dynamic posi- 904, and 906) during Ocean Drilling Program Leg 150 (Mountain et al., 1994). Cored intervals are tioning, fourteen holes were cored in the shown in white. Also shown are the locations of Deep Sea Drilling Project Site 612 (Leg 95) and the Continental Offshore Stratigraphic Test (COST) B-3 well. The COST B3 well was used to establish eastern Atlantic Ocean on board the first-order age and facies successions. These sediments were cored to establish a history of sea- Caldrill I. The results convinced the scien- level variations along the mid-Atlantic U.S. continental margin. Mission-specific drilling platform Expedition 313 continued the coring in modern water depths of 30–35 m and recovered nearshore tific community of the value of multiple and onshore sediments deposited during Neogene changes in global sea level. holes throughout the ocean. In 1967, Global Marine was contracted to design a ship expressly for the purpose of SOD. Seven days later, Leg 2 began coring The JOIDES Resolution With SIO as the prime contractor, the across the Atlantic. The scientific party of Deep Sea Drilling Project (DSDP), using eight included two female micropaleoen- Ocean Drilling Program (ODP, the Glomar Challenger, was launched tologists, Catherine Nigrini (SIO) and 1983–2003) (Bascom, 1961). Maria Bianca Cita (Instituto di Geologia, By the late 1970s, JOIDES began Universitá di Milano, Italy). This began a exploring alternative vessels. Major Deep Sea Drilling Project (DSDP, tradition of international participation improvements in heave compensation and 1968–1983) that was formalized in 1975: five coun- station-keeping ability offered better cores By 1968, several seminal papers on tries (Federal Republic of Germany, and an expansion of geographic areas that plate tectonics (e.g., Hess, 1962; Vine and France, Japan, the Soviet Union, and the could be explored. More research could be Matthews, 1963; Wilson, 1966) had been UK) became contributing international accomplished with expanded laboratories published. These papers were based on partners in the International Phase of and more scientists. The SEDCO/BP 471, sparse data, leaving many unconvinced. Ocean Drilling (IPOD). Today, 23 coun- an oil exploration vessel, was chosen, Interpretation of marine magnetic anoma- tries are part of the IODP consortium, highlighting the advances in technology lies (e.g., Pitman et al., 1968) and better and women comprise about half of the generated by the petroleum industry. earthquake data (e.g., Isacks et al., 1968) science team. Funding for the new program came from provided additional support for this the- Technological development continually the United States and member countries. ory. For many, final confirmation came improved drilling, coring, and logging. Texas A&M University was awarded the from SOD. In 1970, the first re-entry cone was contract. The SEDCO/BP 471 was con- As with Project Mohole, whose objec- deployed (Leg 15, Site 146, Venezuelan verted to a scientific drilling vessel, the tive was seismically defined, Leg 1 of the Basin), allowing the drill string to be JOIDES Resolution, and on 11 January Glomar Challenger and all subsequent pulled, a new bit attached, and coring in 1985 commenced operations. Unlike petro- expeditions have used seismic surveys to the same hole to continue. This enabled