BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 Vol. 32, pp. 429-436 DECEMBER 1. 1921 



INCREASED OCEANIC SALINITY AS ONE CAUSE OF 

 INCREASED CLIMATIC CONTRASTS ^ 



BY STEPHEN SARGENT VISHER " 



{Prese7ited before the Society December 28, 1020) 



CONTENTS 



'I'age 



Introduction 42Q 



Salinity decreases evaporation 429 



Salinity lowers the freezing point 430 



Salinity affects the rate of deep-sea circulation 432 



Possibilities of a reversal in direction of the deep-sea circulation 434 



Introduction 



One of the great problems of geology is the explanation of the differ- 

 ences between tlie climate of the present and that of the past. Today 

 there are great contrasts from zone to zone and from season to season. 

 During much of the past there was relative uniformity from latitude to 

 latitude and from summer to winter. Doubtless many factors helped 

 bring about this change. One factor that appears not to have been dis- 

 cussed, however, is increased salinity of the ocean. There is a general 

 agreement among geologists that the ocean has become increasingly saline 

 throughout the ages. Indeed, calculations of the rate of accumulation 

 of salt have been a favorite method of arriving at estimates of the age of 

 the ocean and hence of the earliest marine sediments. So far as known, 

 however, no geologist or climatologist has discussed the probable climatic 

 effects of increased salinity. Yet it seems clear that an increase in 

 salinity must have a slight effect on climate, and may possibly help to 

 explain some of the puzzling facts of earth history. 



Salinity decreases Evaporation 

 The change from a sliglit salinity, when the ocean was young, to the 



^ Manuscript received by the Secretary of tlie Society .Inly f!, lllill. 

 - Introduced 1)y Ellsworth Huntington. 



(429) 



