DISCUSSION OF THE SUBSURFACE INVESTI- 

 GATION 



TJeuteiiaiit C'oiniiiiiiKler Kuwauu II. S.mjtx. United States Coast CUiavd 



Oceanographical investigation of the subsurface water of the iee 

 reirions has always been recoofnized as one of the most important 

 "hranc'hes of tlie scientiric work of the ice patrol, which held hopes of 

 some dav leading us to a clear and correct knowledge of the be- 

 lun ior of floating ice in the Xorth Atlantic. It is obvious that ob- 

 servations restricted solely to the surface do not furnish a true and 

 fOMiplete picture of the circulation and it is only by including sub- 

 surface investigation that we can hope to obtain a correct view of 

 the interaction between the water masses as a whole. Some years 

 agi) a program upon which this investigation should be carried out, 

 or most nearly approximated, was formulated by the interdepart- 

 mental board charged with the administration of the patrol, and the 

 program was pursued for several years, especially during the ice 

 seasons of 1921, ld'2± and 1923. Briefly it consists of five line> 

 drawn so as to radiate from a central point on the southern part of 

 the (rrand Banks: 48^ ."iC north. 50° 25' west, the oft'shore ends of 

 wliuli terminate in the deep Atlantic water well seaward of the slope 

 and thus cross more or less at right angles to currents long known 

 to exist along the Atlantic faces of the Grand Bank. One radial 

 hue extends across the Bank from 43° 50' north, 50^ 25' west, tc 

 Cape Race, Newfoundland. Stations, so called, are located alouM 

 these lines at both fretpient and critical points, and at these station^ 

 records of temperatui-e and salinity are made at various depths from 

 tlie siu'face downward to the limit of active circulation. 



A line of oceanographic stations then is equivalent to passing a 

 !)lane vertically downward through the water so as to cut a section 

 of tlic water mass nKUc or less at right angles to the continental 

 .-loj)t'. Furnished with these tempei-atures and salinities in a series 

 of sections, we are able to chart tlie position and volume of watei 

 masses of varying "character, which, for oui- interest in i)articular. i-^ 

 the icy cunent from the north. In general it has been found to Mow 

 rloekwi.sc around the Atlantic slopes of the Grand Bank and is the 

 • iirrcnt wjiich transports icebergs into ni(>n:!cing j)ositions along the 

 -teaniship lanes. 



A Utrge amount of tlata were collected during the ice season of 

 .\i'22 and 1923. and the fall of 1923. in a('c<»rdance with the program 



