468 Sayles — Dilemma of P aleoclimatolo gists . 



ray, 16 who states the case graphically and in few words, 

 the influence of the ocean waters on onr temperatures is 

 as follows : 



"It is thus not only the surface-water that may give off heat 

 to the air, but a great body of water extending to several hun- 

 dred metres in depth, and hence the great influence of the sea on 

 winter climates. The capacity of water for heat is very great 

 compared with that of the air. Supposing that we have 1 cubic 

 metre of water giving off enough heat to the air to lower the 

 temperature of the water one degree, this heat would be sufficient 

 to raise the temperature of more than 3,000 cubic metres of air by 

 one degree. An example will show the importance of this. Sup- 

 pose a body of water, 700,000 square kilometres in extent and 200 

 metres deep, to give off enough heat to the air in winter to lower 

 the water-temperature one degree, then the heat given off would 

 be sufficient to raise the temperature of a stratum of air covering 

 the whole of Europe to a height of 4,000 metres on an average ten 

 degrees. This explains how the Gulf Stream renders the climate 

 of northern Europe so much milder in winter than would be 

 expected from its northerly latitude. We shall see later on that 

 the oceanographical researches of the last few years give reason 

 to hope that it will even be possible to predict the winter temper- 

 ature of northern Europe from the temperature of the sea some 

 time in advance. ' ' 



It is seen from this account that the transfer of a few 

 degrees of heat from a large body of water means a great 

 increase of heat in the atmosphere. 



It is certain that cooler climatic conditions accompany 

 and follow mountain building and vulcanism, although not 

 all of these diastrophic periods had world-wide con- 

 tinental ice sheets. There would appear to be some 

 causal connection between diastrophism and cooler 

 climates, and to many that connection would seem to be 

 the emergence of the continents and thus the breaking up 

 to a large extent of the warm water heating system of the 

 earth. Did the emergent continents really effect the 

 cooling? 



In the case of the Pleistocene ice age the cooling effect 

 was a very slow one. All through the warm Eocene the 

 continents were emergent and yet there was no great cool- 

 ing, except local glaciation in the early Eocene, until the 

 Miocene and Pliocene. It is true that no great mountains 

 existed in the Eocene comparable with those of the Plio- 



