8 THE OCEAN 



miles from it the one thousand fathom line 

 extends. From this latter contour line to the 

 two thousand fathom limit the slope is less 

 abrupt. It varies from forty miles off 

 George's Banks to one hundred miles off New 

 Jersey and is narrowest off Hatteras, where it 

 sweeps in to within about fifteen miles of the 

 coast. 



Off the southern coast of New England the 

 continental shelf slopes very gradually to the 

 one hundred fathom line, but here it falls off 

 abruptly, forming a steep bank known as the 

 Gulf Stream Slope, from the fact that it forms 

 the western edge or boundary of the Gulf 

 Stream. 



Although a great many islands are merely 

 elevations of these plateaus which rise above 

 the shallow water, yet other islands rise very 

 abruptly from great depths. Many of these 

 are merely the tips of volcanic mountain peaks 

 whose greatest masses lie hidden far beneath 

 the sea and which, if raised to sea level, would 

 make our mightiest mountains appear like 

 mere hills. In many of these islands the 

 slopes are so abrupt that there is practically 



