■9- 



mid-ocean ridge and associated rift valley was verified by six crossings 

 of this topographic feature. A towed magnetometer produced a continuous 

 plot of the total intensity of the earth's magnetic field along the ship's 

 track. Forty- seven piston cores of the bottom sediment were obtained. 

 Multiple photographs of the bottom were taken at 23 stations. Thirty 

 hydrographic stations were occupied and consisted of serial observations 

 of temperature, salinity, and oxygen. Sixteen large volume water samples, 

 representative of all of the water masses, were collected for C-l4 age 

 determination. Biological collections included 11 bottom trawls and 

 80 plankton samples. Additional observations included measurements of 

 the heat flow through the ocean floor, and propagation of sound through 

 the SOFAR channel. 



Under the direction of John E. Nafe, as Chief Scientist, VEMA made 

 passages from Fremantle to Adelaide and from Adelaide to Wellington. 

 During the early part of this program seismic refraction measurements 

 were undertaken in cooperation withHMAS DIAMAISTINA. During the remainder 

 of the passage the program of observations under way and at stations 

 was closely similar to that of the Cape Town to Fremantle traverse. 



VEMA 18 Itinerary 



Figure 5 



Leave Cape Town 

 Arrive Mauritius 

 Leave Mauritius 

 Arrive Fremantle 

 Leave Fremantle 

 Arrive Wellington 



Manik Talwani, as Chief Scientist, directed the work of VEMA from 

 Cape Town to Mauritius. Marcus Langseth was in charge from Mauritius 

 to Wellington. The underway program included continuous magnetic, topo- 

 graphic, gravity, and seismic reflection measurements. At the Stations 

 cores and Camera Stations were the most common combinations, with more 

 emphasis than usual being placed on plankton sampling. In the area 

 south of Australia a number of bottom trawl stations have been occupied. 

 The passage from Bass to Wellington will begin about July 25th. Parti- 

 cular emphasis is placed on comparison of total sediment thickness with 

 that found in the Atlantic Ocean. 



VEMA 19 (1963) 



VEMA 19 (1963) is being planned to enter the Indian Ocean via 

 either Suez or Cape Town, proceeding to Kerguelen and thence to Fremantle, 

 The new R/V COHRAD, to be operated by Lamont Geological Observatory, will 

 also spend three months in the Indian Ocean in I963. 



During all VEMA cruises, the following program is being carried out 

 under the supervision of the investigators named. Dr. Maurice Ewing is 

 the principal investigator on all VEMA cruises. 



