Co-Chief Scientist Roger Larson aboard JOIDES Resolution (in 1990) holds a sample of Middle Jurassic basalt, the oldest oceanic crust that has been recovered to date
The drill crew uses a variety of mechanical and hydraulic
devices to extend the drill string to the sea floor. In 5,500 meters of
water, it takes 12 hours for the drill bit to reach the sea floor where
drilling can begin. Photo courtesy of the Joint Oceanographic
Institutions.
Scientists aboard JOIDES Resolution describe and sample sediment cores. Photo courtesy of the Joint Oceanographic Institutions.
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Roger Larson,
Professor of Oceanography Roger Larson earned a B.S. in geology from Iowa State University and a Ph.D. from Scripps Institution of Oceanography. He was a researcher at Lamont-Doherty for 10 years until he came to URI in 1980. He specializes in the history of world-widw crustal production, geological consequences of superplume episodes, and tectonic and volcanic history of the Mesozoic-aged Pacific. |
No one knew quite what they would find once drilling began. In those early days, there were no samples deeper than the longest piston core that had been taken from about 20m into the seabed. Marine geology at the time was in a state of great upheaval. The concept of "sea-floor spreading" had recently been proposed as an oceanic extension of "continental drift," a very unpopular idea in most American circles. For example, in 1967 when I was a graduate student and one year before Leg 1 of DSDP left the dock, one of our professors offered to bet anyone in the room $20 that DSDP would recover a continuous Phanerozoic sediment section and bottom out in Precambrian basement beneath the deep seafloor. In doing this, he echoed the views of the famous American geologist James D. Dana more than 100 years earlier who also believed in the fixity of continents and ocean basins. In addition, my professor demonstrated that it is hard to make major advances in scientific thinking without improved technology. As Bertolt Brecht put it, "Astronomy did not progress for 1,000 years because astronomers did not have a telescope."
Glomar Challenger became an inward-looking "telescope" that revolutionized the way we think about the Earth almost as completely and as quickly as Galileo changed our view of the solar system in 1610 when he first saw moons revolving around Jupiter. Ken Hsu, a Chinese scientist by birth and a scientist aboard Leg 3, wrote a book entitled "Challenger at Sea" that includes a dramatic description of his reaction to the results of that cruise. On that historic leg, the seafloor spreading hypothesis was directly tested and supported by every hole drilled. "The drilling campaign of Leg 3 was one of the greatest triumphs in geology," Hsu wrote. "I was lucky to be there, and to make a conversion from Saul to Paul. Twenty years after I left China, I finally learned to think like an American, like a European."
Leg 13 in 1970 brought a completely different but also dramatic discovery and eventually led to the shared international funding of DSDP. Scientists on Leg 13 discovered that the Mediterranean Sea had completely dried up eight million years ago, as the Straits of Gibralter were dammed shut by the continents of Africa and Europe jostling together a bit more closely than usual. This was big news, not only in Europe but also in the United States. The co-chief scientists were Bill Ryan, an American from Lamont and Hsu. During a news conference in the U.S., Ryan was asked how many of the other nine scientists aboard Leg 13 were Americans besides himself. His answer? None. This was not a problem for scientists, as the experts on Mediterranean geology naturally were mainly Europeans. However, this was something of a paradox to the National Science Foundation (NSF). NSF was paying 100 percent of the costs with American dollars for a project that was, during Leg 13, 90 percent non-American. Thus, negotiations began for a new phase, the International Phase of Ocean Drilling (IPOD), which began on Leg 35 in 1974 with Germany and the USSR as the original international members. Eventually, they were joined by France, the United Kingdom, Japan, and other American universities: the University of Hawaii, Oregon State University, the University of Rhode Island, Texas A&M University, and the University of Texas. Even with this international funding and participation, the U.S. still provided about half the funding and about half the shipboard scientists. DSDP-IPOD was operated by Scripps, and Glomar Challenger was an American ship.
DSDP-IPOD lasted until Leg 96 in 1983. I'm not sure why it was shut down, other than government funding agencies don't like to have projects go on indefinitely, and the ship was getting old. It certainly was not for lack of interest or success. In any event, knowing of the imminent demise of DSDP, we convened the first Conference on Ocean Drilling (COSOD-I) that I chaired in 1981 to build the rationale and support for a new scientific ocean drilling program. Out of COSOD-I grew the present Ocean Drilling Program (ODP) that first went to sea in 1985 with a new ship, the JOIDES Resolution and a new science operator, Texas A&M. The original international partners, minus the USSR, were joined by two international consortiums: one of smaller European countries and the other from Canada and Australia. The funding and participation levels have remained with at least 50 percent shares coming from the U.S. ODP has just finished its 73rd leg, and probably will be extended through 2003. We drilled the 1,000th site in the combined DSDP-ODP program in January 1996.
U.S. interests are looked after in ODP by the American scientists who sit on the international committees and panels and by an all-U.S. group of scientists, the U.S. Science Advisory Committee (USSAC) for ODP. I chair USSAC, a committee of about 15 scientists with interests and experience in scientific ocean drilling. Originally conceived at the beginning of ODP as a group to simply manage post-cruise science funding for American shipboard scientists, USSAC recently has become a group that speaks for U.S. interests in many scientific and policy matters. For example, about a year ago, USSAC proposed that U.S. representation on the Planning Committee, the most powerful scientific committee within ODP, should be broadened from just the 10 member U.S. institutions, each holding a reserved seat from the start, to any U.S. scientist at any institution with strong scientific credentials and broad ODP experience. This recently has been implemented, and half of the U.S. members on the ODP planning committee now come from beyond the original U.S. institutions. More recently, NSF asked USSAC to comment for the U.S. in an NSF document on the possibility of expanding scientific ocean drilling after 2003 to include not only our existing drilling capabilities, but also a new drilling system called deep riser, an extension of oil-drilling technology. USSAC agreed, and Japan is actively considering building a ship that could deploy deep-riser technology.
Besides these special issues, USSAC is always about its usual business, which has expanded from doling out post-cruise funding grants to U.S. shipboard scientists. USSAC maintains a Fellowship Program for U.S. graduate students working on ODP science projects, operates a Distinguished Lecturer Series of U.S. scientists who carry the results of scientific ocean drilling to U.S. institutions not heavily involved in ODP, funds Americans to attend workshops on topics of drilling-related interests, and creates educational tools for the classroom, such as CD-ROMs based on scientific problems that can be attacked by scientific ocean drilling.
USSAC's latest project is a compilation of one-page, illustrated abstracts called "ODP's Greatest Hits" which highlights the accomplishments of American scientists with the Ocean Drilling Program. This coincides with the proposed extension of ODP funding from NSF for the next five years. It contains a number of independent and startling results. For example, within this volume scientists present evidence that explain the formation of huge present-day, ore-grade deposits of iron, copper, and zinc precipitated out of hydrothermal fluids heated to more than 300°C and rising as hot springs from the center of spreading ridges. Perhaps even more astonishing is the evidence for much larger amounts of lesser-heated water percolating through the ridge flanks now. Earth was even more thermally active in the Cretaceous than it is now. During the Cretaceous, enormous plumes of mantle rock rose beneath the lithosphere and triggered the formation of individual volcanoes and volcanic plateaus at rates unknown in today's world. In the more recent geological past, giant landslides carved major chunks of land from the sides of the Hawaiian Islands and redeposited the debris hundreds of kilometers away. It appears likely that the oceanic crust is home to an unforseen microbial community called the deep biosphere whose concentration is small, but because oceanic crust is the most common rock sequence on Earth, may contain a significant fraction of Earth's biomass. Throughout all of this, the periodicities of Earth's orbit about the Sun have hammered out a climatic rhythm like a snare drummer keeping the beat in a tune with seemingly endless verses.
All of this would have been considered science fiction 30 years ago, but after more than 170 legs of DSDP and ODP drilling, we now believe that many of these "amazing sea stories" and more are true. Future studies will bring more startling and unexpected discoveries that were not part of anyone's long-range plan, for certainly no one predicted any of the just-cited examples 30 years ago. As Wilbur Wright said in about 1908, "We can see enough now to know that the next Century will be magnificent; only let us be the first to open the roads."
