142 



DEPTHS OF THE OCEAN 



recorded also at the northern end of the deep. The maximum 

 depth, which occurs off Samar Island, is 4767 fathoms. 



Tizard Deep in the South Atlantic is estimated to cover an 

 area of about 468,000 square miles, extending southwards from 

 the equator to lat. 22" S. on the western side of the Mid- 

 Atlantic ridge. The greatest depth recorded in it is 4030 

 fathoms, just south of the equator. In the southern portion of 

 the deep two low rises occur, where depths rather less than 

 3000 fathoms have been recorded. 



Buchanan Deep lies to the east of the Mid- Atlantic ridge in 

 the South Atlantic, between lat. 6° and 22° S., and covers an 

 estimated area of 298,000 square miles. This deep appears to 

 be somewhat flat-bottomed, because the numerous soundings 

 recorded within it do not reach 3100 fathoms though exceeding 

 3000 fathoms, the maximum depth being 3063 fathoms. 



Brooke Deep lies in the North-West Pacific between the 

 latitudes of 12° and 19^ N., and covers an area estimated at 

 about 282,000 square miles. Its greatest depth is 3429 fathoms. 

 Several elevations of the ocean-floor, rising to within 1400, 

 1 1 00, and even 1000 fathoms of the surface, are situated close 

 to the western and northern borders of this deep, separating it 

 from the Challenger Deep on the west, and from the Bailey 

 Deep on the north. 



Moseley Deep lies in the North Atlantic to the east of the 

 Mid- Atlantic ridge between lat. 9° and 18^ N., and is estimated 

 to cover an area of about 279,000 square miles; the deepest 

 sounding recorded within it is 3309 fathoms. 



Bailey Deep lies in the North- West Pacific, between the 

 Brooke and the Murray Deeps, on the Tropic of Cancer. It is 

 estimated to cover an area of about 241,000 square miles, and 

 the deepest sounding recorded in it is 3432 fathoms. 



Jeffrey Deep, in the eastern Indian Ocean, extends in 

 a narrow band round the southern and western coasts of 

 Australia, and as laid down on the map at present is estimated 

 to cover an area of about 228,000 square miles. It is based on 

 nine widely scattered soundings in the southern portion and 

 four soundings closer together at the northern end, leaving a 

 long stretch where no soundings have been taken. Further 

 investigation may show that what is now regarded as one 

 continuous deep is really two distinct deeps. 



Belknap Deep lies in the Central Pacific, extending from 

 about lat. 12 to 17' N., and covering an area estimated at 

 about 165,000 square miles. Near the centre of the deep a 



