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LOCO AND THE BIRTH OF JOIDES

Instead, well before the death of Mohole, a new initiative, focused on oceanic sediments, moved forward. AMSOC itself, under its chairman Hollis Hedberg, had been increasingly inclined toward sediment drilling, partly as a prelude for Mohole and partly as an end in itself. There was much talk of a second ship for this purpose. Then Cesare Emiliani, of the University of Miami, seized the moment by proposing to NSF in 1962 a modest plan to use a small chartered drilling vessel to core sediments in the Caribbean Sea, a project labelled LOCO (LOng COres). The aim, wholly in keeping with his own special research interests, was to decipher and extend the paleoceanographic history of the Neogene when continental glaciers waxed and waned repeatedly in the northern hemisphere, causing major swings in global sea level. The swings could be monitored through the changing microfossil contents and stable isotopic compositions of cored calcareous pelagic sediments.

To help guide this work, Emiliani formed a LOCO advisory group comprising scientists from the major U.S. oceanographic institutions, which evolved into the Joint Oceanographic Institutions for Deep Earth Sampling (JOIDES) organization in 1964, with much encouragement from NSF, and membership of four U.S. oceanographic institutions—Miami, Lamont, Woods Hole, and Scripps. JOIDES was to plan and provide scientific advice; the actual management of projects was to be contracted by NSF to individual JOIDES institutions.

In the interim after the LOCO committee disbanded but before JOIDES formed, Emiliani drove ahead with his project and in 1963, after several attempts, successfully cored through about 55 m of pelagic sediments in 610 m of water off the coast of Jamaica from the small drill vessel Submarex (Emiliani and Jones, 1981). The LOCO program, driven by the ideas and persuasiveness of a single scientist and operated as a normal NSF grant, was a technical and scientific success and cost only about $100,000!

D/V CALDRILL ON THE BLAKE PLATEAU

JOIDES was now hard at work planning future drilling. Its first project, accomplished during 1965, was the drilling of a transect of holes across the Blake Plateau, a marginal submarine plateau at depths of 25-1,000 m off the Atlantic coast of Florida. The objective was to determine the history of relative sea level changes as an entree to the history of tectonic subsidence of a sector of the continental margin, which was known to have been a shallow-water reef area during the Late Cretaceous, some 70 million years ago. For this venture, NSF, on the advice of JOIDES, awarded the managerial contract to Lamont, which seized the offer of an oil company to allow use of its chartered vessel D/V CaMrill while it was in transit from Panama to Canada. In the spirit of JOIDES, the shipboard scientists came from several JOIDES institutions and the U.S. Geological Survey. CaMrill maintained position by monitoring deviations from the vertical of a taut wire from the vessel to an anchor on the seafloor. The data went to a computer that controlled four large outboard motors on the four "corners" of the ship and kept the ship on station. The cores (recovery about 25-70 percent) from the six drill sites nicely documented the Cenozoic drowning history of the old Cretaceous carbonate platform, but everyone understood that the taut-wire station-keeping system would not be applicable to operations in the deep sea, the place everyone wanted to go. For this, a larger vessel with dynamic positioning was required.

DSDP AND D/V GLOMAR CHALLENGER

After the three coring ventures, Guadalupe Mohole, LOCO, and the Blake Plateau, sediment cores were now seen as fairly easy to recover. Microfossils in the cores were generally sufficiently abundant to determine the geologic age of samples. Coring could be extended at least into the upper part of basaltic oceanic basement and its age estimated from the paleontological age of the immediately overlying sediments. In principle, these two simple facts opened the possibility of working out not only the paleoceanographic history of the ocean basins over the past 100 million years (the age of the then-oldest known samples from the ocean floor), but also the age of oceanic crust in all the oceans. A heady vision!

At NSF, awareness was growing that coring of sediments was probably better done from a ship other than the Mohole ship. A sediment-coring ship would need be on station only for days or weeks, while the Mohole ship would be on station for years. The two programs were now being viewed as independent, and so NSF, in 1963, proposed to Congress an Ocean Sediment Coring Program, distinct from the Mohole Project. Funds were provided for the new program in fiscal year 1965.

The trigger for realizing an oceanic drilling project was the acquisition of a practical dynamic positioning system. This system, considerably refined from that deployed from CUSS I, comprised an acoustic transponder dropped from the ship onto the seafloor and an array of four hydrophones lowered a little below the ship's hull. The arrival-time differences of signals from the transponder were processed in a computer, which controlled the ship's main propulsion system and lateral tunnel thrusters, keeping the ship for weeks at a time generally well within a circle with a diameter less than 10 percent of water depth.

JOIDES panels had recommended to NSF the acquisition of a drilling vessel capable of coring in water as much as 6,000 m deep for periods of months in moderate sea conditions and of coring continuously into both sediments and basement rocks to subseafloor depths of several kilometers. NSF, in 1966, awarded to Scripps a prime contract for 18 months of drilling, with a first year's infusion of $7.4 mil



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