286 



University of California Publications. 



[Geology 



The question of the accuracy of the charts herewith pre- 

 sented demands that the various gaps in the series of coast tem- 

 peratures be filled by reliable observations. If the theory of 

 this paper as to the final source of cold water lying along the 

 west coast be correct, serial temperatures in the region from 50° 

 to 55° N. Lat. and about 160° W. Long, should show, at certain 

 seasons of the year, inversions of temperature, that is, a stratum 

 of cold water should be found in intermediate depths overlying 

 warmer water on the ocean bottom. 



In conclusion the following summary of observations and 

 hypotheses in reference to the belt of relatively cold water lying 

 along the west coast of the United States is presented : 



(1) Recent observations indicate that the previous mapping 

 of this cold belt as extending southward to the coast of Lower 

 California is incorrect. The definite belt of cold water can not 

 be traced south of Point Conception. 



(2) In summer the coldest part of this belt is in the vicinity 

 of Cape Blanco and Cape Mendocino. 



(3) The source of this cold coast water is in the ocean depths 

 to the northwestward. 



(4) This cold water at or near the ocean bottom has a slow 

 drift agreeing in direction with the average direction of the 

 surface drift and is driven to the surface on striking the slope 

 of the continental shelf. Local variations in the cold coast water 

 are due to the submarine valleys and other irregularities in the 

 slope of the continental shelf. 



University of California, 

 September, 19o.~>. 



