\ 



m 



43. Fluctuations in vertical temperature structure in brash ice re- 

 gion (1 hour) )S«P. 69 



44. Fluctuations in vertical temperature structure in ice pack re- 

 gion (13 hours) 70 



45. Horizontal distribution of ff M at the surface 71 



46. Horizontal distribution of c f ,at 25 meters 71 



47. Horizontal distribution of <r f ,at 40 meters 72 



48. Vertical <r, section C 73 



49. Vertical <r ( section D 73 



50. Vertical <r { section E 73 



51. Dynamic height contours 75 



52. Composite chart of southern limit of arctic ice pack 76 



53A. Brash and blocks making up the southern limit of drift ice .... 77 

 53B. Blocks and small floes found a few miles north of southern 



ice boundary ^ 



53C. Greater ice cover with increasing latitude 78 



53D. Floe ice extending about 6 feet above water 78 



53E. Glacon showing relative amounts of ice submerged and above 



water 78 



53F. Glacon composed of rotten ice 79 



53G. Flat glacon about 50 feet in diameter 79 



53H. Glacon which appears to have tilted about 90 degrees 79 



54. Transparency measurements made near the surface 82 



55. Plankton stations of the USS NEREUS 86 



56. Displacement volumes of total plankton 87 



57. Locality records of certain copepods 89 



58. Locality records of Echinopluteus 91 



59. Locality records of Ophiopluteus 93 



60. Locality records of Barnacle Nauplius and Cyprid Larva 94 



list off tables 



I. EMERY-GOULD CODE SYSTEM 21 



II. ARCTIC SNAPPER SAMPLES 22 



III. ARCTIC CORE SAMPLES 26 



IV. MINERALS AND ORGANISMS IN ARCTIC BOTTOM SEDI- 

 MENTS 29 



V. DIATOMS IN ARCTIC BOTTOM SEDIMENTS 31 



VI. HYDROGRAPHIC DATA 61 



VII. NUMBERS OF PRINCIPAL ORGANISMS TAKEN BY THE 



USS NEREUS IN THE BERING AND CHUKCHI SEAS, 1947 .. 90 



EST RICT-^ S 



* 'REGTRICTI 



