Margaret Leinen inspects the interior of a re-entry cone. It is used to guide the drill string into a site after bit changes or when a previously drilled site is re-occupied. The photo was taken in 1991.
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Margaret S. Leinen, Dean of the Graduate School of Oceanography and Vice Provost for Marine Programs Margaret Leinen, appointed dean of GSO in 1991, is one of only three women in the United States to head a major oceanographic institution. Leinen earned a PhD in 1980 from GSO and became a full professor of oceanography in 1989. Leinen serves on many domestic and international scientific committees, is a Fellow of the Geological Society of America, and has participated in more than 15 scientific cruises since 1974. |
GSO first joined the Drilling Project as a partner and member of JOI in the early 1970's. DSDP was expanding from a program run by a few institutions to one with broad support from the oceanographic and geoscience communities. (Roger Larson's article describes early achievements of DSDP.) Our partnership in the scientific planning and management of DSDP opened new opportunities for GSO faculty and students and led to the expansion of the geological oceanography program at GSO.
During the first phase of drilling, Jim Kennett, GSO faculty member, and his colleagues and students at GSO, focused on high-latitude drilling. Kennett served as paleontologist on Leg 21, the first high-latitude drilling leg, and was co-chief scientist of Leg 29 between New Zealand and Antarctica which produced the first cores near the Antarctic Circle. Kennett's work provided the first long-term histories of sedimentation in the Southern Ocean and emphasized the remarkably rapid changes in sedimentation, ocean circulation, and climate that took place during the Miocene (5 to 23 myBP). The critical role of high-latitude oceans in controlling climate became a long-term theme of GSO paleoceanography leading to Kennett's role as co-chief scientist on Legs 90 and 113 in the Southern Ocean and later to the role played by Michael Arthur, GSO faculty member and co-chief scientist on Leg 105 of ODP in the northern high latitudes. Others who participated in high latitude drilling legs have included Monty Hampton, URI geology professor (Leg 29).
In 1974, GSO recruited Ross Heath and Ted Moore (then at Oregon State) to join Kennett and Norm Watkins, who were already here, in an exciting new paleoceanographic initiative at GSO. Heath and Moore were no strangers to DSDP. Moore had sail-ed on Leg 8 (back when scientists had private staterooms) and Heath had been a co-chief on Leg 16. These two legs had formed the backbone of a new understanding of equatorial Pacific history. Equatorial Pacific studies, especially paleoceanographic studies, have been another recurring research theme at GSO. This theme was developed further by Heath and Moore's students, Nick Pisias (scientist Leg 85; co-chief scientist Leg 138), Dean Dunn (scientist, Leg 85), Karen Romine (scientist, Leg 92), me (scientist, Legs 68 and 138), and others who spent time at GSO, like Larry Mayer (now a scientist at the University of New Brunswick and a member of the Ocean Drilling Program Council; scientist on Legs 68 and 130, co-chief scientist on Legs 85 and 138), Lloyd Keigwin (a GSO student now a scientist at Woods Hole Oceanographic Institution; scientist on Leg 68), and Terri King (a student of Nick Pisias who became a GSO faculty member; scientist on Legs 138, 154, and 162).
In 1974, Germany and the USSR joined the Deep Sea Drilling Program as full members, and the program made the transition to the International Program of Drilling (IPOD). During this time, GSO was also expanding its capabilities in geological oceanography. GSO recruited oceanography professors Roger Larson, Jeff Fox, and Bob Detrick who had a profound influence on the nature of geophysical and ridge crest drilling in IPOD and its successor, ODP.
One of Larson's interests was the unique geophysical character of the Pacific Ocean during the Jurassic and Cretaceous (205 to 63 myBP, the ages of the great dinosaurs). Obtaining sediments and igneous rock from the oldest part of the ocean has been one of Larson's quests since his earliest participation in DSDP (co-chief, Leg 31), IPOD (co-chief, Leg 62), and ODP (co-chief, Leg 129 and scientist, Leg 144). In the course of this search for the oldest crust, Larson made significant advances in our ability to drill long sediment sequences and to drill through the flinty cherts of the North Pacific.
Fox joined GSO while serving as the chair of the Ocean Crustal panel, responsible for drilling through the ocean basement rocks and in hydrothermal environments. Under his leadership, the first hydrothermal systems were drilled in the Galapagos Islands (Bender, GSO faculty, scientist, Leg 70), and hydrothermal history transects were drilled in the Pacific (Leinen, co-chief, Leg 92).
During the late 1970's, the drilling community realized that new drilling capabilities were necessary for several types of geologic problems, especially the evolution of the polar oceans and the crust at active spreading centers. The community envisioned an international effort with expanded international membership and became engaged in a lively debate about upgrading the existing ship or buying a new vessel. One suggestion was to convert the Glomar Explorer, a vessel that had been used to raise a Soviet submarine from the deep Pacific seafloor, into a drill ship. Others argued for the construction of a new vessel capable of drilling in environments that had oil potential. This discussion culminated in the Conference on Scientific Ocean Drilling (COSOD) in 1981 led by a steering committee chaired by Larson. Detrick, Arthur, and Moore (then at EXXON) all served on working groups of that conference.
As the international geological community debated the scientific problems to be addressed and how to stimulate the international investment for a new drilling vessel, it became clear that we might be looking at a substantial time interval between the end of the approved DSDP program, agreement on a new vessel, and the beginning of a new drilling program. Kennett played a major role in addressing the need for a continuation of drilling during this transition. Kennett, his colleagues, and students highlighted the importance of "thresholds and gateways" for ocean circulation changes that caused dramatic changes in the chemistry and circulation of the ocean and in the atmospheric and climatic response to these changes. He emphasized the capabilities of the Glomar Challenger for pale-oceanographic drilling, and his work stimulated a proposal for a transition period that emphasized this paleoceanographic drilling and set the state to continue drilling. The "thresholds and gateways" theme has extended into the current Ocean Drilling Program.
The Ocean Drilling Program (ODP) leased a new drilling vessel, the SEDCO/BP 471, later named the JOIDES Resolution. The new ship was bigger, had more laboratory and bunk space, more drill depth capability, better stability in heavy weather, and fit the expanded goals of the program.
Larson played a pivotal role in the scientific leadership of the newly formed Ocean Drilling Program. He was the first chair of the primary science Planning Committee (PCOM) and hosted the first international JOIDES office.
ODP began with fanfare and high hopes. By the mid-1980's, it was clear that technological development and perhaps even alternate drilling platforms would be needed in the future to drill the most exciting targets. EXCOM commissioned another Conference on Scientific Ocean Drilling (COSOD II). Fox was a member of the steering committee, and I served on a working group.
During this time, Fox and Detrick played an important role in the leadership of the Lithosphere Panel. They were very influential in convincing the drilling program to develop technology for drilling in young crustal areas with little sediment cover to support the drill string and for the development of a suite of tools for studying the hydrothermal fluids circulating in these rocks. Detrick served as a co-chief scientist on the first leg (Leg 106) to experiment with new hard rock guide bases (which now have become routine) for drilling a ridge crest. Several legs have explored this challenging technical problem since.
Larson served as co-chief scientist on one of the most memorable ODP legs (Leg 129) on which he realized his goal to drill crust of Jurassic age (200 myBP), the oldest rocks ever recovered from the ocean. But even more exciting were Larson's ideas about the origin of Earth's magnetic field changes during the Mesozoica superplume of igneous and volcanic activity arising from changes at the core/mantle boundary and resulting in the generation of massive submarine volcanic eruptions.
Michael Arthur, a paleocean-ographer with interests in the Jurassic and Cretaceous ocean, had been a staff scientist with the DSDP before becoming a faculty member. He led one of the very first ODP cruises (Labrador Sea, Leg 105). He was joined by three GSO students, Kathleen Dadey (who also participated on Legs 126 and 138), Frank Hall, and Jim Zachos (participants on Leg 120).
Haraldur Sigurdsson and Steve Carey have long been interested in explosive volcanism and have been actively involved in the debate about the extinctions associated with the end of the Cretaceous period and beginning of the Paleocene (the Cretaceous/Tertiary boundary). Among those extinctions are extinctions of several dinosaur groups. In their research, they showed that features of this important transition period could not be explained by explosive volcanism. With Steve D'Hondt, they focused instead on field work in the Caribbean to look at the relationship between a major asteroid impact in Mexico at the end of the Cretaceous and the oceanographic and evolutionary events at the same time. Their work culminated in an ODP leg (Leg 165) in the Caribbean which drilled holes to test the hypothesis that the Mexican asteroid impact generated ocean tsunamis and other effects that could be seen in the sediments. They were joined by several other GSO and GSO-trained scientists, including John King and Rick Murray. The cruise was enormously successful and drilled the first complete sequence of sediments that showed the fallout from the collision debris itself and a "Strangelove Ocean" devoid of almost all microscopic life because of the sulfuric acid generated from the volcanic gas interaction with the atmosphere. Now the Ocean Drilling Program is in the process of another transition in which it considers new and alternate drilling platforms. An exciting proposal for Japanese construction of a very large drilling vessel is being considered by the international community. ODP has renewed its scientific advisory structure to focus on the themes identified in its long-range plan: the dynamics of the environment and the ocean crust and mantle. GSO scientists are strong contributors to this evolution of the program. Larson serves as a member of the Science Committee that guides the entire program, and D'Hondt is a member of the Science Steering and Evaluation Panel on Earth's Environment.
Some of our contributions have been the people who left GSO to have greater involvement with the drilling program. Bob Duce, dean from 1987 to 1991, left URI to become dean of the College of Geosciences and Maritime Studies at Texas A&M. This college is the home of the Ocean Drilling Program, and Duce became the dean responsible for its administration. In 1996, Fox left GSO to become the chief scientist of the Ocean Drilling Program. Both Duce and Fox have made substantial contributions to improving the quality of the program and its responsiveness to the scientific community.
The most interesting thing for me to watch over these past twenty years at GSO has been the way in which faculty participation has led students to participate in the drilling program and to establish their own new research themes. Among the former students who participated in cruises and have not already been mentioned are Lowell Stott, Eve Arnold (who describes her experience in Ocean Drilling Fellowships), Alexandra Isern, Gail Lombari, Marion Rideout, Sassan Salehipour, Lew Abrams, and Christian Lacasse.
