NORTH PACIFIC 83 



The area, however, where a high sea has been regularly reported 

 in August during more than 10 percent of the time extends something 

 like 1.200 miles farther southward in midocean in the Pacific (to about 

 latitude 25° N.) than in the Atlantic (to about 45° or 46° N. only ; cf. 

 pi. IX with pi. I). A high sea is also reported about four times as 

 often on the average (8 or 9 percent) from southern Japan southward, 

 past the northern Philippines to the offing of Mindanao in the open 

 Pacific, as well as locally in the northern part of the South China Sea, 

 than it is along the Atlantic seaboard of North America as a whole 

 from Cape Hatteras southward, in the West Indies, in the Gulf of 

 Mexico, or in the Caribbean (average about 1 or 2 percent). This 

 difference between the two oceans may be partially due to the fact that 

 the prevailing winds of summer are somewhat weaker along the south- 

 eastern United States and in the Gulf of Mexico at that season than 

 in the western side of the Pacific at corresponding latitudes, where 

 they average 12 to 14 knots. But it is also likely that the dangerous 

 waves raised by tropical hurricanes have been included more often 

 in the reports of the state of the sea in the western tropical Pacific 

 for the late summer than they have in the Atlantic, for the typhoon 

 season is not only at its height then, but dangerous storms of this 

 nature cross the East and South China Seas much more often than 

 they do the western tropical Atlantic, the Caribbean, or the Gulf of 

 Mexico. The Pilot Charts for August, for example, show the tracks 

 of 169 for that general part of the Pacific for the 25-year period from 

 1921 to 1945, but only 36 for the western tropical Atlantic for the 39- 

 year period from 1901 to 1940. 



Neither are there any apparent counterparts in the North Atlantic 

 to the "pools," so to speak, in mid-Pacific, the one extending south- 

 easterly from the Hawaiian Islands, the other lying farther south- 

 eastward in the equatorial belt, where high seas are reported in sum- 

 mer in frequency as great as 10 percent. No doubt the Northeast 

 Trades are responsible in the first case, for it is about here that they 

 average their strongest in summer, and the Southeast Trades for the 

 second. 



On the other hand, a high sea is reported considerably less often 

 along the coasts of Central America and of Lower California in the 

 eastern tropical Pacific in August (0 to 2 percent) than it is in the 

 corresponding latitudinal belt of the eastern Atlantic from Gibraltar 

 to Cape Verde (7 to 14 percent). At the same time, what may be 

 named the "east-tropical smooth" (outlined on the charts by the con- 

 tours for 60 percent low) extends some 1,500 miles farther northward 

 in the eastern side of the Pacific, where it reaches to southern Califor- 

 nia, than in the eastern side of the Atlantic. The smoothness of the 

 sea in this part of the Pacific no doubt reflects the fact that the inshore 



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