THE DEPTH AND MARINE DEPOSITS OF THE PACIFIC OCEAN. 149 



THE DEPTHS OF THE PACIFIC OCEAN. 



The additions which have been made to our knowledge of the bathymeti'y 

 of the Pacific Ocean in recent years, not only by Dr. Alexander Agassiz's 

 cruises, but also by other American ships and by cable ships, make it desir- 

 able to summarize what is known of the depth of this great ocean at the 

 present time. The general result has been to increase the area between 

 2000 and 3000 fathoms, and to limit the area greater than 3000 fathoms, 

 while the various contour-lines of depth have become more complicated and 

 definite. It may be said that the bathymetry of the Pacific is now known 

 in all its broad general outlines. 



On Map I. accompanying this paper, the depth conditions in the Pacific 

 are indicated on an equal surface projection hemisphere by varying shades of 

 blue color — the darker the shade of blue the deeper the water — contour 

 lines being drawn in at depths of 100, 500, 1000, 2000, 3000, 4000, and 5000 

 fathoms. All soundings in depths exceeding 1000 fathoms are indicated on 

 the map by the first two figures : thus 1468 is given as 14, 5269 as 52, the 

 last two figures being omitted. A similar map for the large part of the 

 Pacific traversed by the "Albatross" during the 1899-1900 cruise was pub- 

 lished in Dr. Alexander Agassiz's preliminary report^ in January, 1902, and 

 a comparison of that map with the present one shows that in the interval of 

 seven years few deep-sea soundings have been added to the southeastern 

 regions of the Pacific, apart from those taken by the "Albatross " during 

 the 1904-1905 cruise. Considerable differences may be noticed in the con- 

 formation of the deeper parts of the ocean, especially where the depth 

 exceeds 3000 fathoms. This is to some extent due to the fact that in 

 drawing in the deep contours the plan has been followed of extending the 

 areas where there was no evidence to the contrary, and thus in many cases 

 imiting together two or more areas previously isolated. 



The southwestern portion of the Pacific lying to the east of Australia 

 and Tasmania has been dealt with in great detail in a paper ^ prepared by 



1 Mem. Mus. Comp. ZooL, vol. XXVI., no. 1, Map IB. 



2 On the depth, temperature of the ocean waters, and marine deposits, of the Southwest Pacific 

 Ocean. Queensland Geogr. Jour., N. S., vol. XXL, pp. 71-134, 1906. 



