TOPOGRAPHY OF THE INDIAN OCEAN. 



TOPOGRAPHY OF THE INDIAN OCEAN WEST OF MALABAR. 



Plates 7, 8. 



The Admiralty Chart (PI. 7) contains a sufficient number of soundings to 

 throw very important light on the depths of the Indian Ocean between the 

 Malabar coast and the region south, and the Laccadives and Maldives. The 

 one-hundred-fathom hne runs nearly parallel to the coast at a distance vary- 

 ing from twenty-five to sixty miles, and again parallel to this from twenty- 

 five to thirty miles further west runs the one-thousand-fathom line. 



The Laccadives (PI. 8) rise from a plateau bounded by the one-thousand- 

 fathom line, separated on the eastern side from the continental shelf by a 

 channel of from ten to forty miles in width with a depth between ten and 

 twelve hundred fathoms, the width of the channel and its depth gradually 

 increasing as we go south ; so that between Kalpeni and Kiltan the distance 

 between the eastern edge of the Laccadives and the one-thousand-fathom 

 continental line is fully seventy-five miles, and the depth separating it from 

 the Indian coast more than thirteen hundred fathoms. 



Within the one-thousand-fathom line surrounding the Laccadives plateau, 

 rise quite abruptly the smaller banks and plateaus upon which are the coral 

 reefs of the group. The five-hundred-fathom line of the plateaus and banks 

 are within moderate distances of the outer edge of the reef flats. This is 

 indicated by the charts for Cora Divh, Sesostris Bank, and Bassas de Pedro, 

 as well as for Cherbaniani Reef, Byramgore, Chetlat, Bitra, Peremul Par, 

 Kiltan, Cardamum, Piti Bank, and Agatti. The same is the case for the 

 more southern Laccadives, Elicalpeni Bank, Androth, Karawatti, Suheli Par, 

 and Kalpeni, which rise from the deeper parts of the channel, over one thou- 

 sand fathoms, separating the southern Laccadives from the Malabar conti- 

 nental shelf. It is interesting to note in the Laccadives the existence of 

 extensive banks similar in outline to some of the Maldive Banks or Plateaus, 

 such as Cora Divh, Sesostris Bank, the Bassas de Pedro, and Piti Bank with 



