662 russell. SEDIMENTATION IN NAVAL WARFARE [Ch. 35 



atlases of oceanographic conditions for submarines operating in enemy 

 waters, also contained information on bottom types in shallow water 

 and proved to be extremely valuable to our submarine forces. Numer- 

 ous other charts and manuals, with information on beaches, bottom 

 sediments, and similar geologic and oceanographic data, were prepared 

 for special purposes. 



Equipment 



Several types of new equipment for determining the character of the 

 ocean bottom have been developed as a by-product of the work de- 

 scribed above. These include new types of grab samplers and corers 

 (Ewing, Woollard, Vine, and Worzel, 1946; LaFond and Dietz, 1948), 

 one of them for use from a ship underway (Emery and Champion, 

 1948), equipment for photographing the bottom (Ewing, Vine, and 

 Worzel, 1946; Shepard and Emery, 1946), and new types of acoustic 

 equipment. A hydrophone, adapted for dragging over the bottom, 

 gives information on bottom character from the sounds produced (La- 

 Fond, Dietz, and Knauss, in press). Fathometers have been greatly 

 improved. A new type, the "bottom scanner," presents a profile of the 

 bottom below the ship on the face of a cathode-ray oscilloscope (Rus- 

 sell, 1946) . 



OTHER RESEARCH 



In addition to the problems listed above, the Navy has undertaken or 

 sponsored much research in sedimentation and submarine geology not 

 immediately applicable to naval problems. Probably the outstanding 

 example is the work done at Bikini and other atolls of the Marshalls 

 in connection with the atomic bomb tests (Dobrin et al., 1949; Emery, 

 1948b; Emery, Tracey, and Ladd, 1949; Ladd et al, 1948; Munk and 

 Sargent, 1948; Revelle, 1947; Sargent and Austin, 1949; Tracey et al., 

 1948). When all the work accomplished during the summers of 1947 

 and 1948 is published, we shall have our first detailed account of the 

 characteristics of a coral atoll. 



Other examples of Navy or Navy-sponsored research are the joint 

 sedimentation survey of Lake Mead, Nevada (cooperating agencies 

 include the Bureau of Reclamation, the Geological Survey, the Coast 

 and Geodetic Survey, and, for the Navy Department, the Bureau of 

 Ships, the Bureau of Ordnance, the Hydrographic Office, and the Navy 

 Electronics Laboratory) ; Ewing's geophysical work (Ewing, Wool- 

 lard, and Vine, 1946; Ewing, Worzel, and Pekeris, 1948; Press and 

 Ewing, 1948) ; Phleger's laboratory for the study of Recent foramini- 

 fera; and fundamental studies on waves and shore processes (Einstein, 



