32. Why do tide ranges in the same geographical areas of the 

 world differ so greatly? 



In addition to effects of the moon and sun, tide ranges are affected 

 by shape and dimension of the coastline and sea floor. In some restricted 

 water areas (bays, channels, etc.), heights may build up to 50 feet and 

 tidal currents of as much as 10 knots occur. 



Tides moving upstream in an estuary are slowed down by bottom 

 friction, and the following water piles up. The water rises more rapidly 

 than it falls, and the flood stream has higher velocity than the ebb. 



Some areas of great tidal ranges are the Bay of Fundy, Bristol Chan- 

 nel, and the Sea of Okhotsk. The famous Bay of Fundy tidal bore 

 moves more than 100 billion tons of water a day. 



There are also areas in the world that are almost tideless; among 

 these are the Mediterranean, Baltic, and Adriatic Seas, and the Gulf of 

 Mexico. 



Deacon, G. E. R. (Ed.) 



Seas, Maps, and Men, Doubleday and Company, 1962. 

 Gaskell, T. F. 



World Beneath the Oceans, American Museum of Natural History, 



1964. 

 King, Cuchlaine A. M. 



Oceanography for Geographers, Edward Arnold Ltd. (London), 1962. 



34 



