MARINE SCIENCE 53 



liydrographic observations, bottom sediment coring, bottom and mid-deptli pho- 

 tography, bathythermograph measurements, continuous magnetic field measure- 

 ments ; plankton sampling, bottom biological trawls, ocean floor temperature 

 gradients, seismic refraction transmission studies, and gravity measurements. 

 One of the major laboratories concentrates heavily on the hydrography and sonar 

 work and a third on seismic refraction measurements and ocean cores. 



Consequently, the ships for each laboratory must have great versatility and a 

 primary space allocation for their major field of research. In some cases this 

 means equipment for mid-depth operations, in another equipment for aerological 

 work, in another complex electronic systems for acoustical analysis, in another 

 heavy equipment for frequently operating on bottom, and in another a large 

 capacity for carrying explosives. These varying requirements demand different 

 arrangements and qualifications for the ships ; much more than a fairly stand- 

 ardized observational program for surveys. It is therefore felt to be important 

 that each ship be designed largely to fulfill the requirements of the laboratory 

 which will use it. 



There is a great need for additional modern and more able ships. These 

 ships must be available on a long-term basis to the laboratories to which they 

 are assigned and not subject to being withdrawn on short notice for more "ur- 

 gent" (another name used for applied research) programs. This can probably 

 best be accomplished by transferring the ships to the nonprofit laboratory. Simi- 

 larly it is important that the jurisdiction of supporting facilities be vested in the 

 nonprofit laboratories. 



The funding of ship operations poses a great headache on a project basis. 

 Sometimes ships have had to depart on long cruises without sufficient funds 

 to assure the completion of over half the cruise. This is caused by the uncer- 

 tainty of the continuation of an active project up for renewal several months 

 after the ship has put to sea. In other cases it results from the uncertainty of 

 funding a new project in a new fiscal year. This uncertainty causes poorer 

 -cruise planning than could be desired, and considerable inefficiency and difficulty 

 to secure the necessary funds for the completion of a cruise. Funds for opera- 

 tions of privately owned vessels operating for basic research are as vital to the 

 continued healthy growth of basic research in oceanography as for Government 

 ■vessels. 



It is vital to have the operation of research vessels in basic research under 

 the direct control of the operating laboratory and the chief scientist on board, 

 if great opportunities are to be seized when they offer themselves, rather than a 

 ;Strict adherence to schedule. It is also vital to the esprit de corps as well as 

 the cooperative working of the professional seamen and the professional scien- 

 tists. There are difficulties enough on small ships operating in distant oceans 

 without the additional controversies arising from divided operational control. 



Defense Applications 



SEISMIC KEFEACTION AT SEA 



These studies result in the geological information of layer thickness and 

 Telocity. From the velocity reasonable conclusions can be made about the types 

 ■of rocks or sediments. These data have defense applications in defining the 

 acoustic impedance of the bottom which controls the fraction of incident energy 

 reflected from bottom. Sonar systems which may use bottom reflections there- 

 fore depend on this work for any possibility of predictions. The earliest work 

 in seismic refractions in deep water led to the consideration of the whole velocity 

 depth profile in the deep ocean. This velocity depth profile suggested to Dr. 

 Ewing the possibilities of the system now referred to as Sofar which has been 

 •covered in some detail by Dr. Iselin. 



The bottom topography studies record the water depths along ship's tracks 

 and try to relate these to physiographic provinces. Just after World War II, 

 the state of knowledge of the physiographic provinces were so primitive that it 

 was thought that the ocean floors were flat featureless plains which were occa- 

 sionally interrupted by continents, islands, trenches, and a few ridges such as 

 ■the Mid-Atlantic Ridge. 



Now we recognize that these were only the major features and many physio- 

 graphic features such as the continental rise, abyssal plains, multitudinous sea- 

 mounts, small rises, midocean canyons, and plateau-like steps exist. 



