52 



MARIOX EXPEDITION TO DAVIS STItAIT AND BAFFIN BAY 



latitude of St. Johns, Newfoiindlancl, 1 to 2 inches in thickness, 

 out from the coast for a distance of several miles. Rodman ( 1 

 p. 20) has published a table showino; the a]ii)roxiinate dates of 

 pearance and disai)])earance of ice alono- the Labrador and > 

 foundland coasts. 



On several previous occasions in discussino; certain rc<rions we 

 called attention to tiie important inHuence which l)athymetrical 

 ditions have on ice distribution. The Labrador shelf is no excej 

 to the rule, providing a high road, so to speak, along which the 

 may easily advance to lower latitudes. The bathymetrical ma 

 Davis Strait shows that the Labrador shelf is much wider than 

 along the other coasts of this region. Tt maintains an average ^^ 

 of 80 miles, as determined by the r)()()-fathom isobatli. from ' 

 Chidley, Labradoi-. southward to Hamilton Inlet, thence to the 

 tude of Cape Race it spreads out very wide: for example, ol 

 Johns it measures nearly 2.S() miles. The breadth and ireneral 



The Offing of the Labrador Coast in June 



Figure 26. — The procession of pack ice whicli is continually bcins' borne south 

 along the Labrador coast for seven months of the year by the cold current, 

 coastal belt of pack ice is claimed to play an important role in the south- 

 distribution of the iceberss. they being fended off the coast and kept out ii 

 cold current. (Photograph by E. M. Kindle.) 



line of the east North American pack along this coastal stre i 

 largely a reflection of the depths. In years of abundant pac 

 outer edge of the field olf St. Johns has been recorded a hundi 

 two hundred miles from the coast. 



As summer advances, the i)ack melts back toward its iku 

 roots uncovering first the NewfouiuHand and then the Lai 

 coast lines. The Strait of Belle Isle is usually open to navi^ 

 from July to December, the first of the trans-Atlantic steame 

 tering June 15 to ,Iiily 1 and the last i)assing out the first w« 

 December. The Labrador coast is often free of ])ack ice. at lea 

 navigation, during July, while in other summers the coast ha; x 

 continually hampered.-^** 



^8 An excellent example <if the rate of dissipation of the Labrador pack is affo 

 the fact that the (J<nJth(uih expedition in early .Tune. Ji'l'S. found a field of pack 

 tending along a large i)art of the Labrador sh<'lf of IS.ndo square miles area, 

 ■weeks later the Marion expedition found these waters dear and all ice disappeared 

 ice in the western North Atlantic was markedly below normal the year of 1928. 



