AN OCEANOGRAPHIC OPERATION CONDUCTED THROUGH 

 AN ICE COVERED EMBAYMENT 



Dr. Lloyd R. Breslau 



Leo J. Fisher 

 F. M. Daugherty, Jr. 

 James P. Welsh 



ABSTRACT 



An oceanographic environmental survey was conducted in the vicinity 

 of Thule, Greenland, diiring March-April I968 to determine the direction 

 of movement of the ice at spring thaw. Operations were conducted dur- 

 ing extremely adverse weather conditions. Air temperatures dropped to 

 as low as -45°F and wind speeds averaged about 15 knots. 



Standard oceanographic instruments and techniques were adapted 

 for use through a thick ice cover. Current measurements, sea floor 

 photographs, ice thickness measurements, and through-ice echo sound- 

 ings were obtained. 



The measured ciirrents are predominantly tidal and will result in 

 an oscillatory motion of the water in the area with a slow net trans- 

 port seaward through the channel between Wolstenholme Island and the 

 mainland. These currents are not strong enough to have any signifi- 

 cant effect on the break-up and movement of the ice, and consequently, 

 the dominant factor affecting break-up and ice movement are wind di- 

 rection and speed. 



Introduction 



In January 19^8, an Air Force B-52 jet aircraft crashed on fast 

 ice approximately 10 miles southwest of Thule Air Force Base, Green- 

 land. The aircraft fragments were scattered over the surface of the 

 ice on impact. Intense heat generated by fire associated with the 

 crash melted the surface layer of the ice. As the ice melt refroze, 

 scane of the fragmented material became imbedded in the ice. To de- 

 termine the direction of movement of the ice and imbedded material at 

 spring thaw, a knowledge of the svirface currents in the vicinity of 

 the crash site was required. The U.S. Naval Oceanographic Office 

 (NAVOCEANO) was requested by the Air Force in February 1968 to obtain 

 the required surface current information. During the planning of the 

 operation, spot photographs of the sea floor were requested to obtain 

 information on the nature of the bottom in the vicinity of the crash 

 site. In addition, a non-interference research experiment was incor- 

 porated into the operational field survey to investigate the feasi- 

 bility of through-the-ice echo sovinding. 



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