rv DEPTHS AND DEPOSITS OF THE OCEAN 137 



less than 500 fathoms in the Pacific being about 5 million 

 square miles, as compared with 2 million square miles for the 

 area between 500 and 1000 fathoms. 



The Pacific Ocean differs from the Atlantic in having much shore-siopes 

 more steeply sloping shores both on the east and west sides, of the Pacific, 

 greater depths, and very many small islands, chiefly of volcanic 

 and coral formation. This gives a very irregular appearance to 

 the depth-map of the Pacific, and shows sharper contrasts in rises 

 and depressions of the ocean-floor than are found in either of the 

 other great ocean basins. Along the west coasts of both North 

 and South America the steep slopes are most remarkable, the 

 land descending from the great heights of the Rocky Mountains 

 and the Andes to depths of 2000 fathoms and more in a 

 comparatively very short horizontal distance. This is par- 

 ticularly striking off the coast of South America between the 

 latitudes of 10° and 35° S., where depths of over 3000 fathoms 

 (in three cases over 4000 fathoms) are found within a very short 

 distance from the shore-line. It is noteworthy that all the very deep 

 soundings recorded in depths of over 4000 fathoms are taken com'^arSvei- 

 comparatively near land, viz. off South America (as just near land. 

 mentioned), off the Aleutian Islands, the Kurile Islands and 

 Japan, the Philippines, the Ladrone Islands, the Pelew Islands, 

 between the Solomon Islands and New Pommerania, and to the 

 north of New Zealand, east of the Kermadec and Friendly 

 Islands. 



The greater part of the area with depths less than 1000 

 fathoms lies in the western Pacific, in the fringe of partially 

 enclosed seas which lie between the continents of Asia and 

 Australia and the islands fringing their eastern shores, such as 

 the Behring Sea, the Sea of Japan, the Yellow Sea, China Sea, 

 Java and Arafura Seas, and around the New Zealand plateau. 



The area covered by depths between 1000 and 2000 fathoms Pacific area 

 lies mostly south of the equator, that part north of the equator beJ^^gtTiooo 

 consisting of detached areas in the Behring Sea, Sea of Okotsk, and 2000 

 Sea of Japan, and China Sea, narrow bands round the various ^' °^^^' 

 island groups and along the western shores of North America, 

 widening greatly off the coast of Central America, and nine small 

 areas where the floor of the ocean rises from surrounding depths 

 of over 2000 fathoms. The area in the South Pacific with depths 

 between looo and 2000 fathoms was formerly supposed to extend 

 from the Southern Ocean between Auckland Islands and the 

 Antarctic continent in a wide band north-eastv/ards towards the 

 coasts of Central America without a break, but recent investiga- 



