SPECIALUNCORRECTED ISSUE ON SCIENTIFIC OCEAN DRILLING: LOOKING TO THE FUTURE PROOF

Years of Scientific5 Ocean Drilling By Keir Becker, James A. Austin Jr., Neville Exon, Susan Humphris, Miriam Kastner, Judith A. McKenzie, Kenneth G. Miller, Kiyoshi Suyehiro, and Asahiko Taira

ABSTRACT. Nearly a century after the first systematic study of the global ocean and drilling in 1961 using the Global Marine seafloor by HMS Challenger (1871–1876), US scientists began to drill beneath the sea- drilling barge CUSS I (Figure 1), to which floor to unlock the secrets of the ~70% of ’s surface covered by the seas. Fifty years four large outboard motors had been of scientific ocean drilling by teams of international partners has provided unparalleled added so it could operate as the first advancements in Earth sciences. Here, we briefly review the history, impacts, and sci- dynamically positioned drilling vessel in entific achievements of five decades of coordinated scientific ocean drilling. the world (Bascom, 1961). In a success- ful demonstration, phase I cored 170 m Miscellaneous Society (AMSOC). At that of sediments and 13 meters of underlying PROJECT MOHOLE (1958–1964) time, was yet to be formally at a deep-water site offshore Baja The origins of scientific ocean drilling hypothesized, but it was already known California. Huge public interest devel- date back more than 60 years to Project from seafloor seismic refraction studies oped, thanks to a prominent article by Mohole. It was originally suggested in (e.g., Raitt, 1956) that the Mohorovičić the famous novelist John Steinbeck in Life 1957 by and Harry Hess, seismic discontinuity between and magazine (Steinbeck, 1961). Recovering and then proposed to the National Science mantle (Moho) was much shallower subseafloor basalt was a major scientific Foundation (NSF) by the famously beneath the ocean floor than the conti- accomplishment at the time, so much so named, partly self-organized American nents. NSF supported phase I of Mohole that it inspired a congratulatory telegram

a FIGURE 1. (a) The drilling vessel CUSS I as used during phase 1 of Project Mohole. (b) A first examination of cores onboard ship during Project Mohole.

b

14 | Vol.32, No.1 UNCORRECTED PROOF from US President John F. Kennedy (Figure 2). However, the effort to con- tinue drilling to the Mohole was derailed by Congressional politics when it was evaluating various expensive proposals to build an appropriate, custom drilling ves- sel. As a result, Project Mohole had faded away by 1965. (See Munk, 1980; Maxwell, 1993; and Winterer, 2000, for many fasci- nating details of the Mohole story.)

JOIDES AND THE DEEP SEA DRILLING PROJECT (1968–1983) Meanwhile, the directors of four major US oceanographic institutions (Lamont Geo- logical Observatory, Institute for Marine Sciences at the University of Miami, Scripps Institution of Oceanography, and Woods Hole Oceanographic Institu- tion) recognized the value of a concerted program to core the sedimentary record throughout the ocean. In 1964 they signed a memorandum establishing the Joint Oceanographic Institutions Deep Earth Sampling (JOIDES) program. Their vision was to propose to NSF separate scientific FIGURE 2. The congratulatory telegram from US President John F. Kennedy drilling “projects” operated by individual at the successful conclusion of phase 1 of Project Mohole. oceanographic institutions. The first JOI- DES project was a 1965 transect of holes across the Blake Plateau, managed by and DSDP for the 1975–1983 Interna- expedition cored and dated the basal Lamont and drilled by the chartered ves- tional Phase of Ocean Drilling (IPOD), sediments immediately above oceanic sel Caldrill. The Deep Sea Drilling Proj- which added an emphasis on penetrating basement in a transect across the South ect (DSDP) was the second JOIDES proj- the basaltic basement beneath ocean sed- Atlantic, confirming that crustal age ect, managed by Scripps starting in 1966, iments. In 1975, the first JOIDES Office increased nearly linearly with distance including construction of the drilling ves- was established (at Lamont-Doherty Geo- from the Mid-Atlantic Ridge spreading sel (see Spotlight 1). logical Observatory) to coordinate sci- center. In the summer of 1968, the University of entific planning for the program, with a DSDP was inherently explor- Washington joined JOIDES, and DSDP subtle change in its title “Joint Oceano- atory and global-ranging, and in that scientific drilling began with Leg 1 sedi- graphic Institutions for Deep Earth Sam- mode made many key scientific con- ment coring in the Gulf of , in the pling” (though the acronym remained the tributions—see the section below on western Atlantic offshore Bahamas, and same). Scientific ocean drilling has been Selected Achievements of Scientific on the Bermuda Rise. Originally proposed international ever since (Spotlight 2), and Ocean Drilling (1968-2018). DSDP also as an 18-month project, DSDP was so suc- has always been held up as a prime exam- made important technological contribu- cessful that it was extended through 1983. ple of successful international scientific tions, including development of deep- DSDP remained an NSF-funded Amer- collaboration (e.g., Smith et al., 2010). water reentry capabilities (1970) and the ican effort through 1974 as the National Revelle (1981) provided an early sum- hydraulic piston corer (1979) for soft Ocean Sediment Coring (NOSC) pro- mary of the scientific impact of DSDP. to semi-lithified sediments that contin- gram. Between 1973 and 1975, more US The most famous DSDP result may well ues to be the workhorse of the science institutions and the first international have been direct verification of sea- of paleoceanography (see Moore and partners (Spotlight 2) joined JOIDES floor spreading by Leg 3 in 1968. That Backman, 2019, in this issue).

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OCEAN DRILLING PROGRAM the European Consortium for Ocean community was small, and development UNCORRECTED(1983–2003) Research Drilling (ECORD), primarily and reviewPROOF of drilling expedition plans DSDP was formally concluded in 1983, to access shallow-water and high-latitude was often top-down. However, during and Texas A&M University was named scientific targets not suitableb for either of ODP and the various phases of IODP, all as the science operator for the Ocean the other . proposals have been reviewed in the con- Drilling Program (ODP), leasing a newer This multi-platform vision was for- text of a succession of community-driven, and more capable commercial drilling mally realized in late 2003 as the Integrated multi-year, overarching science plans vessel rechristened JOIDES Resolution Ocean Drilling Program (IODP), whose (Spotlight 4). Program-based review pan- that also included a number of state- operations began in summer 2004. The els and committees have evolved through of-the-art laboratories for initial anal- first decade of IODP was organized on the years, both in number and com- yses (Spotlight 5). Whereas DSDP had a model with a significant component of plexity, from a theme/region focus, with been exploratory, ODP was designed internationally commingled funding and added engineering, logging, and technol- as a more thematically driven program, strong central management provided by ogy panels/working groups, to the com- with drilling expeditions based on pro- IODP Management International Inc. paratively simple current model with a posals submitted to the JOIDES advisory (IODP-MI). Unfortunately, there were single panel of both “science” and “data” structure by the scientific community delays in launching Chikyu and in com- experts who vet all proposals for all plat- in response to multi-year science plans pleting the major overhaul of JOIDES forms and integrate anonymous external (Spotlight 4) developed in periodic inter- Resolution in 2006–2008. Within this first peer review. An environmental protec- national workshops (see section below on phase of IODP, available funding was not tion panel, with some members serving Scientific Ocean Drilling and its Advisory sufficient to achieve the original vision for decades, stands guard over the safety Structure). In this planning mode, ODP for full-time operations by the two drill- of operations. Since the beginning of was very successful across a broad range ships and one or two annual MSP oper- ODP ~35 years ago, the nurturing of pro- of scientific themes that gave the com- ations. Nevertheless, the first IODP ponents and their ideas has been the key munity 18 years of continued scientific (2003–2013) made very significant sci- to success, with spectacular results. The ocean drilling from 1985 to 2003. NSF entific and technological contributions program is open to scientists located provided the majority (about two-thirds) towards an impressive list of ODP/IODP throughout the globe, and has fostered of the financial support throughout ODP, accomplishments; highlights are listed in innovative and transformative science but there were also substantial financial a later section on Selected Achievements from the tropics to the poles, in every contributions from international partner of Scientific Ocean Drilling (1968-2018), ocean basin, and over every epoch of the countries and consortia (Spotlight 2). and achievements are documented in last 170 million years. much more detail by Stein et al. (2014). INTEGRATED OCEAN DRILLING For its second 10 years, IODP contin- EDUCATIONAL CONTRIBUTIONS PROGRAM (2003–2013) AND ued to provide the same two drillships OF SCIENTIFIC OCEAN DRILLING INTERNATIONAL OCEAN and MSP opportunities, keeping the Spotlight 11 highlights the importance of DISCOVERY PROGRAM acronym but changing the program name current IODP efforts in training the next (2013–2023) to the International Ocean Discovery generation of geoscientists, but interna- Starting in the mid-1990s, momentum Program. This second phase of IODP tional scientific ocean drilling has had a began to develop for a multi-platform significantly simplified the funding and long history in this regard since DSDP. continuation of scientific ocean drilling advisory structure, resulting in more effi- Several of the authors of this paper— beyond ODP. A new program was envi- cient operations with no central manage- and many of our colleagues—partici- sioned to involve increased international ment organization (Spotlight 3) and an pated in DSDP expeditions or site sur- co-funding to make three types of drill- emphasis on regional ship track planning veys during graduate school or early ing capabilities available to the worldwide for JOIDES Resolution (Spotlight 7). postdoctoral positions (Spotlight 12). The scientific community: a riser drilling skills we developed through this partic- (Yamada et al., 2019, in this issue) vessel SCIENTIFIC OCEAN DRILLING ipation have been crucial in our career supplied by Japan that was later named AND ITS ADVISORY STRUCTURE development, and the international net- Chikyu (Japanese for “Earth”; Spotlight 8); Scientific ocean drilling has always ben- works of scientific contacts we made then continued riserless drilling provided by efited from positive synergy between have developed into lifelong collabora- the United States using a significantly proposal writers (proponents), a pro- tions. During ODP and IODP, oppor- updated JOIDES Resolution (Spotlight 5); gram-based review system, and external tunities like this have been provided to and mission-specific platforms (MSPs; peer review starting during ODP. During graduate students, and many of them Spotlight 10) furnished occasionally by DSDP, all drilling was exploratory, the have gone on to highly productive careers

16 Oceanography | Vol.32, No.1 in the geosciences. In addition, activities the expansion and contraction of records of the Cretaceous/Paleogene UNCORRECTEDhave been extended to undergraduates, global ice volume over millions of years PROOFmass extinction 66.05 million years ago K–12, and informal education venues. as well as shorter glacial-interglacial (infamous for extinction of the non- Educators now sail on drilling expedi- cycles avian dinosaurs), linking a large aster- tions and organize many activities, some • Enabled construction of a ~100- ​ oid impact and the mass extinction, in real time, to engage students and the million-​year history of the timing, and showing that life reestablished public as they study Earth’s systems. rates, and estimated amplitudes of robust ecosystems in the impact area global sea level change, documenting within 30,000 years of the impact SELECTED ACHIEVEMENTS OF the relative contributions to sea level SCIENTIFIC OCEAN DRILLING made by tectonics, ice sheet fluctua- Plate Tectonics and Geodynamics (1968–2018) tions, and sediment supply • Provided early, direct confirmation of Significant accomplishments of scien- • Provided high-resolution records of the and the theory of tific ocean drilling in many subjects are rates of sea level change of >50 mm yr–1 plate tectonics. explored in more detail in thematic arti- in the last 10–15 kyr following the Last • Nearly four decades later, long-term cles in this issue. Major achievements Glacial Maximum seismic observatories in scientific from DSDP and ODP were nicely sum- • Showed that Antarctica was largely ice- ocean drilling holes beneath the sea- marized in the “Major Achievements of free before 35–40 million years ago, floor provided the first direct evidence Scientific Ocean Drilling” section of the with development of continental-scale for the age-dependent growth of the IODP Initial Science Plan (Coffin et al., ice sheets starting at 34–35 million oceanic lithosphere—an essential tenet 2001, pp. 10–16). Stein et al (2014) care- years ago of plate tectonics fully documented additional achieve- ments from the first phase of IODP. We offer the following as a non-exclusive list of important overall contributions of 50 years of scientific ocean drilling. Fifty years of scientific ocean drilling Climate, Ocean, and Sea Level by teams of international partners History • Enabled development of the field of has provided unparalleled advancements pre-Quaternary paleoceanography “ in Earth sciences. . • Helped define and refine the geomag- netic polarity timescale and its link to astronomical chronologies back to 66 million years ago, providing key con- straints on today’s standard Geological ” Time Scale • Documented the major role of the • Provided the first thick sequences of • Extended the marine sedimentary development of the Circum-Antarctic intact oceanic crust below thick lay- record back into the Middle Jurassic Current system in glaciation and global ers of marine sediment, revealing the (~170 million years ago), allowing thermal evolution in the Cenozoic complexity of crustal construction pro- reconstruction of planetary history • Showed that the Arctic Ocean was a cesses, and demonstrating that crustal since then at million-year resolution or semi-restricted warm sea for much sections generated at slow-spread- better of the early Cenozoic, transitioning ing, fast-spreading, and thickly sedi-

• Tracked changes in atmospheric CO2 through the Miocene to become an mented ridges are distinctly different in through the Cenozoic and linked these ice-covered ocean at about 6 million architecture to Earth’s surface temperature history years ago in the “icehouse world” that • Advanced our understanding of con- • Documented large carbon-cycle continues to the present tinental breakup, faulting, rifting, and changes associated with marine black • Established the sensitivity of monsoons associated magmatism and processes, shales, anoxic events, and episodes to climate controls, particularly the constraining the timing of the transi- of abrupt climate change such as the linkages between the Indian and Asian tion from rifting to seafloor spreading Paleocene/Eocene Thermal Maximum monsoons to uplift of the Himalayas • Showed that mantle plumes that feed • Linked Earth’s orbital variability to during the collision of India with Asia volcanic hotspot systems like the long-term climate changes, including • Recovered the most complete marine Hawaii-Emperor island/seamount

Oceanography | March 2019 17 chain may not be stationary but Revealed significant flows of fluids Smith, D.K., N. Exon, F.J.A.A. Barriga, and Y. Tatsumi. • 2010. Ocean drilling: Forty years of interna- UNCORRECTEDcan move at rates half those of plate through virtually all parts of the sea- tional PROOF cooperation. Eos, Transactions American motions, providing direct input into floor, from mid-ocean ridges to deep- Geophysical Union 91(43):393–404, https://doi.org/​ 10.1029/2010EO430001. the debate on the geodynamic nature sea trenches Stein, R., D.K. Blackman, F. Inagaki, and H.-C. Larsen. of Earth’s mantle Documented the relationships among 2014. Earth and Life Processes Discovered from • Subseafloor Environments: A Decade of Science • Sampled oceanic plateaus formed as fluid circulation and the alteration and Achieved by the Integrated Ocean Drilling large igneous provinces (LIPs) by mas- aging of the oceanic crust Program (IODP). Developments in Marine , vol. 7, Elsevier. sive Mesozoic volcanism over short • Revealed for the first time the internal Steinbeck, J. 1961. High drama of bold thrust through periods, documenting links to Mesozoic structure of seafloor massive sulfide ocean floor: Earth’s second layer is tapped in pre- lude to Mohole. Life, April 14, 1961, 110–121. anoxic events and suggesting links to deposits Winterer, E.L. 2000. Scientific ocean drilling, from changes in convection in the outer core Successfully sampled subseafloor gas AMSOC to COMPOST. Pp. 117–127 in 50 Years of • Ocean Discovery: National Science Foundation associated with the “Cretaceous Quiet hydrate formations to investigate their 1950–2000. Ocean Studies Board, National Zone,” during which reversals of Earth’s role in the carbon cycle, climate, and Research Council, National Academy Press. Yamada, Y., B. Dugan, T. Hirose, and S. Saito. 2019. magnetic field were very infrequent slope stability Riser drilling: Access to deep subseafloor science. • Illuminated fault zone behavior and • Recovered deeply sourced (many kilo- Oceanography 32(1):XX–XX, https://doi.org/XXXX. related tectonic processes at active plate meters) mantle serpentinites in sub- AUTHORS boundaries where Earth’s largest earth- duction forearc mud volcanoes as well Keir Becker ([email protected]) is Professor, Department of Marine Geosciences, Rosenstiel quakes and tsunamis are generated as associated slab-derived fluids with School of Marine and Atmospheric Science, • Investigated the nature of and pro- elevated pH, methane, and hydrogen University of Miami, FL, USA. James A. Austin Jr. is Senior Research Scientist, Institute for , cesses active within subduction zones concentrations that support unusual The University of Texas at Austin, TX, USA. by drilling through the subduction microbial and megafauna biota Neville Exon is Emeritus Professor, Research School of Earth Sciences, Australian National University, décollement to recover subducted sed- • Developed subseafloor boreholeCanberra, Australia. Susan Humphris is Senior iments, formation fluid, and the igne- hydrological observatory systems with Scientist, Geology & Geophysics Department, Woods Hole Oceanographic Institution, Woods Hole, MA, ous slab, allowing an initial inventory long-term monitoring capabilities that USA. Miriam Kastner is Distinguished Professor of of Earth materials that are recycled into enabled scientists to conduct short- Earth Sciences, Scripps Institution of Oceanography, University of California, , La Jolla, CA, the mantle by subducting plates and long-term in situ experiments USA. Judith A. McKenzie is Emeritus Professor, • Revealed the presence of one of the within Earth’s crust, revealing for the ETH Zürich, Zürich, Switzerland. Kenneth G. Miller is Distinguished Professor, Department of Earth world’s largest and the most recent “salt first time the actual directions of flow and Planetary Sciences, Rutgers University, The giant” deposited in the late Miocene of subseafloor fluids State University of New Jersey, Piscataway, NJ, USA. Kiyoshi Suyehiro is Principal Scientist and Mediterranean Sea as a result of a tem- Asahiko Taira is President, Japan Agency for porary closure or restriction of the con- REFERENCES Marine- and Technology (JAMSTEC), Bascom, W. 1961. 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18 Oceanography | Vol.32, No.1