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U. S, COAST AND GEODETIC SURVEY 



The USCScGS Ship PIOKEER will sail in mid-February of 1964 from 

 San Francisco to take part- in the International Indian Ocean 

 Expedition, returning to San Francisco the following September o 

 In addition to underway observations^ en route to and from the 

 Indian Ocean^ the PIOldEER will concentrate on gravity, magnetic j, 

 and hydrographic operations in the Andaman Sea and the eastern Bay 

 of Bengal, Space will be made available aboard the vessel for two 

 meteorologists and one or two biologists. Three north- south profiles 

 of oceanographic stations are planned from 5°N to 5 S across the Equator 

 south of the Bay of Bengal, 



These are only tentative plans covering work on specific Coast 

 and Geodetic Survey projects » It is anticipated that they will be 

 modified and added to as the information from other participants 

 becomes available and as other organizations develop cooperative 

 programs with the PIONEER « 



These plans are predicated on the assumption that TRANSIT navi- 

 gation will be available for determing ship positions throughout the 

 expedition. 



Leg I - San Francisco to Singapore 



Leg II - Singapore Trincomalee (Figure l6) 



From Singapore, the track will be northwest through the Malacca 

 Straits into the Andaman Sea, The actual tracklines in the Andaman 

 Sea will depend in part on the results of the work of the ARGO which 

 returns from this area in the early summer of 1963„ In general, how- 

 ever, there will be a series of sawtooth crossings of the Andaman Sea 

 carrying out all of the standard underway observations with special 

 attention paid to the bathymetry and the gravity worko Sediment cores 

 and bottom photographs will be taken in the Andaman Sea along these 

 lines o Rock dredgings will be attempted at places where the topography 

 suggests that rock outcrops might be present o Planned tracklines in 

 this area will be modified in the field as dictated by the bottom 

 topography and gravity anomalies encountered. The pattern will include 

 at least two crossings of the Andaman- Wicobar Ridge into depths of at 

 least 3000 meters west of the ridge. These could conceivably be 

 through Ten Degree Channel and Duncan Pass, At the northern end of 

 the Andaman Sea, special lines shall be run to determine if submarine 

 channelling extends seaward of the mouths of the Irrawaddi River, 



From the Andaman Sea, the ship will pass into the Bay of Bengal 

 where the underway operations, cores (or dredgings), and bottom 

 photography will continue along a series of East-West lines at 

 approximately two-degree spacing from the coast of Burma out to 

 approximately 88°E, Topographic, gravimetric, or magnetic anoma- 

 lies found along these lines will be developed more fully. Special 



