Geology 



equator has been spoken of as a region of calms the 

 Doldrums but along the coastal belts there are often 

 strong breezes, which blow from the sea during the 

 day and from the land during the night. 



These winds are due to a difference between what is 

 called the " specific heat" of the water and that of the 

 land. The specific heat of a substance is the quantity of 

 heat which is necessary to raise unit mass of the substance 

 one degree in temperature, and it differs very considerably 

 for different substances. 



Water possesses a much higher specific heat than 

 does rock, and the result of this is that during the day, 

 while the Sun is pouring down heat upon sea and land 

 alike, for each unit of heat received the rocks rise more 

 in temperature than does the water of the ocean. Thus 

 the air over the land gets hotter, and therefore lighter, 

 than that over the sea, which flows in, as a sea breeze, 

 the air over the land rising. 



In the evening, for similar reasons, the land cools 

 more quickly than the sea, so that some little time after 

 sundown the wind will fall calm, and later spring up in 

 the opposite direction as a land breeze. 



Far more important than these land and sea breezes of 

 the tropics are certain winds which prevail in the Indian 

 Ocean, in Southern Asia, and several other parts of the 

 world. These are the Monsoons or seasonal winds, and 

 are produced owing to the fact that in the regions between 

 longitude 40 E. and 120 E. there is an enormous pre- 

 ponderance of land in the Northern Hemisphere. 



The effect of this is that during the northern summer 

 the great land mass of Asia gets heated up more quickly 

 than the oceanic area to the south, and consequently 



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