SCIENTIFIC RESULTS 7 



in that the ice was scarce. Another circumstance which greatly 

 enhanced the vahie of the observations of the Marion expedition was 

 the fact that the Godthaah expedition simultaneously carried out an 

 oceanographic survey in the more northern waters of Baffin Bay, 

 allowing direct comparison. 



The principal task of the Marlon, expedition w^as the collection of 

 a record of temperature and salinity — tlie raw data — from as many 

 selected points of observation and depths as possible in the waters 

 of Davis Strait. This material, consisting of over 2,000 surface and 

 subsurface observations, has been subjected to Bjerknes's (1910, 1911) 

 hydrodynamic formulae according to the methods employed on 

 international ice patrol and described by Smith (1926, pp. 1-50). 



As a result of the Manon. expedition the prevailing oceanographic 

 circulation of Davis Strait has been mapped from the lower end 

 of Baffin Bay to the latitude of St. Johns, Newfoundland. A com- 

 l)lete report on the dynamic oceanography is to be published in Part 

 2 of this bulletin, entitled " The Marion Expedition Under the Direc- 

 tion of the U. S. Coast Guard, 1928. Scientific Results. The 

 Physical Oceanography of Davis Strait." (In press.) 



The dynamic topographic maps which are described and illus- 

 trated in Smith (1931) have been used in the present paper as 

 the basis of describing and interpreting the direction and movement 

 of the icebergs in Davis Strait. (See especially in this connection fig. 

 95, p. 147. in the present paper.) Our conclusions on the general 

 movement of icebergs in Baffin Bay have been based on the dynamic 

 topographic map (fig, 91, p. 139) constructed from the GodthaaVs 

 observations. The dynamic topographic map showing the stream 

 lines of the gradient currents furnishes an excellent presentation of 

 the normal courses taken by the icebergs, if we assume that the deep- 

 drafted long-life icebergs outside coastal promontories are in the 

 main controlled by ocean currents. On several previous occasions I 

 have found a good agreement between the stream lines of the 

 currents as represented by the dynamic topographic maps (see figs. 

 103, 104, 105, 106, p. 162) and the movement of the bergs in the Grand 

 Bank region. See, in addition. Smith (1927, p. 118) (1927a, pp. 

 70-93). Since the current maps of the Marion expedition are similar 

 in every respect to those constructed on ice patrol, there is every 

 reason to believe the agreement between calculated currents and ice 

 drifts holds equally true for Davis Strait and Baffin Ba}". 



The Mariotis 2,000 observations of salinity and temperature, cov- 

 ering the waters of Davis Strait (see station table data. Part 2 of 

 this bulletin), thus constitute original basic data from which to 

 deduce the circulation and the behavior of the ice. By synthesis 

 with the various earlier data it is now possible to present a connected 

 picture of Arctic ice and of its southward drift. 



FLOATING ICE 



Ice which is sighted floating at sea maj'^ have been formed either 

 on the salt water itself or upon the lancl. Floating ice, therefore, 

 as it is pertinent to the present discussion, separates into two great 

 divisions as it hails from independent sources namely, land ice and 



120860—31 2 



