A Preliminary Report on Expeditions Monsoon and Lusiad 1960 - 1963 University of California, San Diego Scripps Institution of Oceanography Cruises to the Indian Ocean By The Members of the Expedition Edited by Robert L. Fisher S. I. O. Reference 64-19 ― i ― FOREWORD Field participation in the International Indian Ocean Expedition by scientists and research vessels of the University of California's Scripps Institution of Oceanography comprises three multi- program investigations: MONSOON (1960-1), LUSIAD (1962-3) and DODO (1964). All three expeditions, though first broadly outlined in 1959, lie within the cooperative international exploration of the Indian Ocean being sponsored by the Scientific Committee on Oceanic Research and UNESCO. Therefore, though original schedules have to date been met, the programs have in fact been influenced and modified by the plans, interests and findings of other agencies and laboratories, and direct participation by marine scientists, students and trainees from other areas has been welcomed. Although the final SIO IIOE cruise, DODO, is just underway, a preliminary report on some generalized results of the first two expeditions seems appropriate now, with the clear understanding that many conclusions stated here may indeed be premature. Final analyses, syntheses and results will appear in more specialized formal publications and in the proposed SCOR-sponsored atlases which eventually will summarize Indian Ocean Expedition findings. At Scripps Institution, it is customary to give names, rather than number designations, to the major expeditions. The 1960-1 investigation, 3 ½ months in the Indian Ocean, embraced the first SIO field work in the "monsoon seas". It was funded primarily by the Office of Naval Research of the Navy Department, with auxiliary support for personnel and special equipment from the Bureau of Ships and the National Science Foundation. The primarily two-ship 1962-3 cruise, 11 ½ calendar months in the Indian Ocean, drew its name from "Os Lusiadas", the epic epic poem (ca. 1572) of Luis Camões celebrating the early explorations of the Indian Ocean by Portuguese navigators. LUSIAD was a joint operation of the University of California and the University of Rhode Island; the two three-months' equatorial current studies, aboard Argo, were planned ― ii ― and carried out under the over-all direction of John Knauss, formerly of SIO, now Dean of the Graduate School of Oceanography of URI. In greater part, LUSIAD was funded nearly equally by the Navy Department (through ONR and BuShips contracts) and by the National Science Foundation (NSF G-22255). The current cruise on Argo, DODO, receives its support from these same sources. Its name, with a slight bow to Lewis Carroll of course, commemorates the now- extinct flightless bird of Mauritius, an island intimately linked with all three SIO cruises to the Indian Ocean. Robert L. Fisher Director, SIO Indian Ocean Program June 2, 1964 ― iii ― Scripps Institution of Oceanography research vessels Argo and Horizon. R/V Argo carried out Monsoon Expedition and R/V Argo and Horizon carried out Lusiad Expedition. ― 1 ― ACKNOWLEDGMENTS This preliminary report was written by some members of MONSOON and LUSIAD Expeditions, as indicated in the several chapters covering various aspects of the scientific programs, and, in a few instances, by shore-based scientists who worked up samples or data records. Each member of LUSIAD Expedition is indebted to SIO's James Faughn, who visited in advance each Argo port between Manila and Cochin to make logistic and personnel arrangements; he also acted as scientific liaison at these ports and at Djakarta. The bulk of the preparation took place while the editor was based at the Department of Geodesy and Geophysics, Madingley Rise, Cambridge, and would not have occurred without the constant on-the-ground aid at Scripps Institution of Mrs. Marie Jantsch, Thomas W. C. Hilde and David Crouch of the SIO Indian Ocean Program Office. The clerical and logistic services of Mrs. Sue Chappell and Joseph Redfarn at Madingley Rise are gratefully acknowledged. Finally, the editor thanks Sir Edward Bullard and Dr. Maurice Hill for the facilities and support given him during his stay at the Department of Geodesy and Geophysics. ― 2 ― MONSOON EXPEDITION - NARRATIVE A. San Diego to Port Darwin (August 26 – October 17, 1960) The University of California's first oceanographic field study of the Indian Ocean got underway when R/V Argo, with Laurence E. Davis as Master, sailed from San Diego on August 26. George G. Shor, Jr., seismologist, was chief scientist, and the scientific party included eighteen others, primarily physical scientists but also two ichthyologists aboard to make air-borne insect, plankton and fish collections. Programs planned, and carried out in varying degree, for this segment enroute to the Indian Ocean included: short seismic refraction lines employing Argo's 32-foot utility boat as second vessel; continuous underway topographic, magnetic and gravity observations; hydrographic casts, piston and gravity coring, heat flow measurements, bottom photography and dredging, plankton tows and dip-netting on stations; BT's at two-hour intervals while underway; occasional air samples for CO2 analysis and surface water samples for radiocesium analysis. When Argo left San Diego, her first major port of call was to be Suva, Fiji. However, in 1960 Argo was a recently-reactivated and newly-converted vessel, and there were numerous small and large troubles plaguing her electrical circuits and her machinery, and especially the winches. On September 2, near 13°N, 145°W, her starboard-side steering cable nearly parted, and it was necessary to detour to Honolulu for repairs. En route, even so, a short seismic refraction line was attempted on the shelf and the upper slope in the lee, west of the island of Hawaii. Argo was in Honolulu from September 6 – 17, undergoing repairs to the ship's machinery and modifications to the large dredging winch. Due to this unplanned port stop, Suva was dropped from the itinerary and Argo sailed for Cairns, Queensland, on the afternoon of September 17. She reached Cairns on October 6 after brief stops ― 3 ― at Howland (September 24) and Nanumea (September 28). Between these stops, fourteen crew and scientists, in a "two-birds ceremony", were initiated as shellbacks when Argo crossed the Equator at 180° Longitude, a point "neither east nor west, north nor south". On October 1, while crossing the North New Hebrides Trench in the vicinity of Vanikoro Island (site of the shipwreck and loss of La Perouse's Astrolabe and Boussole, incidentally), Argo logged and confirmed a flat trench bottom at 4695 fms uncorrected (sounding velocity 4800 ft/second), about 1100 fms deeper than previously accepted for that trench. (Subsequent detailed exploration here by R/V Spencer F. Baird early in 1962 established that the North New Hebrides Trench reaches a depth of 5010 fms — Matthews-corrected — near Argo's crossing). En route across the Pacific Basin, Argo's complex scientific program yielded, in part, 5 seismic refraction stations (some reversed), 21 gravity cores, 11 temperature probe lowerings, 7 camera stations, 12 micro-plankton tows, 10 radiocesium samples, 11 GEK jogs in the Coral Sea, 8 hydrographic casts, 247 BT's nearly- continuous underway PDR, gravity and magnetic observations, and shore biological collections and a gravity station at Howland Island. At Cairns, three scientists (Belshe, Mero and Von Herzen) and the ship's physician (Chassy) left the expedition; another scientist (Helfer) went ashore to carry out a gravity survey overland to Port Darwin. Three men joined: Robert Thyer of the Australian Bureau of Mineral Resources, Frank Carey of Western Gear Company and Alvin Edgerton, gravity program aide from UCLA. Here also inspections and arrangements were made to charter M/V Malita, Bert Cummings, Master, to serve as primary shooting ship during the Cairns to Djakarta portion of MONSOON. Argo left Cairns on October 8[*], and proceeded under coastal pilot inside the Barrier Reef to Princess Charlotte Sound; during this run the water was too shallow to permit towing of the magnetometer, and the primary program was measurement of gravity. In the Sound, an Argo- tender short seismic line was shot, to check the depth of the Tertiary sediments in the basin. Meanwhile, the biologists were making collections on nearby Wharton Reef. Argo ― 4 ― transited Torres Strait on October 10 and made gravity and magnetic runs southwest of the Strait before anchoring off Thursday Island October 11 to await Malita. Malita had sailed from Cairns on October 9 with two of the seismic party aboard. At Thursday Island a third seismologist, supplies, communications equipment and explosives were put aboard Malita and both ships headed for Tanimbar. On October 12 a 45-mile seismic line was shot on the shelf northwest of Carpenteria Lightship; this was followed by two similar shelf lines the next two days. During this period a great deal of time and effort went into correcting electrical troubles in the scientific equipment aboard Malita. On October 15 Argo and Malita, passing between Tanimbar and the Aroe Islands, reached the smooth-floored middle of the 3800-fm Weber Deep. Here Argo's recently-repaired dredging winch was tested by lowering a gravity corer to the basin floor. During retrieval, the wire walked out of the grooves in the winch's traction drums and snarls developed, necessitating the cutting and long-splicing of the cable before the corer with core was recovered. As a further test of the big winch, however, an otter trawl was towed southeastward along the flat-bottomed Weber Deep. Shortly after midnight a maximum of 12,000 meters of wire was out. No difficulties were experienced during the retrieval, although on surfacing the trawl was found to be wrapped in the cable. The trawl probably did not touch bottom, even at the + slow speed (1.5 - knots) and large wire scope (1.6 – 1.7) tried.