97 



an icebreaker, should the design of the prow be an art based on trial and error? 

 Or, what in icebreaking ability is bought if the power of the breaker is raised 

 from the present 12,000 to 20,000 h.p,? The question of measuring shear has 

 not been considered, yet alone instrL'.mentation developed. 



Of course, synoptic studies of sea ice coverage and movement can con- 

 tinue for a long time in the field and the success, as has been mentioned, de- 

 pends on improvement in extending observation stations and methods, and on 

 improved reporting and classification. Long term field work appears warrant- 

 ed . 



In view of these remarks, it would appear we should expend the effort to 

 build or find facilities that can handle sea ice studies. To further glaciology, 

 laboratories have been built in close proximity or even within glaciers. How- 

 ever, living like a mole inside a chunk of sea ice is not particularly appealing. 

 Any laboratory facility for the study of sea ice should be of sufficient size to 

 handle realistically the transient phenomena and to permit, for example, acous- 

 tic measurements and mechanical properties tests. 



The laboratory facility for ice study should be designed to permit measure- 

 ments within the ice sheet and in the water phase below the ice. The time-pres- 

 sure-temperature functions of this sea ice should be known and under control. 

 There are many facilities for study of problems of the snow-ice and air phase 

 above, but no facilities for study in the water beneath. The correction of this 

 deficiency seems a principal first task in instrumentation for study of the intern- 

 al mechanics of sea ice. Its cost is comparable to that of one field expedition. 



The U.S. Navy Electronics Laboratory maintains a small observation 

 station at Cape Prince of Wales overlooking the Bering Strait for the purpose of 

 studying relationships between the sea ice system and the particular oceanic 

 system of the Chukchi- Bering Seas. Water, ice and heat transport through the 

 Strait is monitored at the station throughout the year. Much effort at the sta- 

 tion has and continues to concern field instrumentation and procedure, ranging 

 from schemes for laying cables across beaches bull-dozed by ice to photograph- 

 ic methods of recording sea ice movement -- a whole discussion in itself. The 

 Cape Prince of Wales location has seemed more pertinent to our work than the 

 Arctic Research Laboratory at Pt. Barrow because the sea ice flux is within 

 immediate reach from the beach. Moreover, the Bering Strait is a singular 

 location connecting two oceanic systems. 



In quick sunamary, the five essential needs are: 



(a) Costly, specialized vehicles, submarine and icebreaker; the cost 

 per field datum is very high necessitating excellent planning. 



(b) Laboratory facilities and studies. 



(c) First field studies in sea ice dynamics. 



(d) A set of equations of state for the phase mixture, sea ice. 



(e) Investigators. 



To reemphasize the point made by Dr. Barnes, the needed investigators 

 are not to be obtained by shifting present workers in the many oceanographic 

 fields, but by growth of interest from outside, i.e. , by new blood coming up. 

 Yet how is this to be done except through the schools represented here today? 

 Are you, or can you include the physics of sea ice in your curricula; can you 

 find an instructor? Sea ice is just as surely a regime of the sea as the marine 

 organisms, the circulation system or the chemistry. 



