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submarine peak, 4,000 feet in height, existed in that part of the ocean, rising very abruptly from the ocean bed on northern, eastern and western sides, with a gentle slope on its southern face.
The ocean bed between San Diego and the Hawaiian Islands is like the Atlantic plateau, gently undulating, but differs in this respect, that it is boldly abrupt near the respective coasts; the character of the bottom soil—a light yellowish brown mud or ooze,—is nearly uniform.
Not so the bed from the Hawaiian Islands westward, which is irregular and mountainous, and the nature of the bottom soil dissimilar,—coral limestone, lumps of lava, coarse sand and ooze, containing particles of lava, coming up in specimen cylinders at various localities on the route sounded. Six (6) submarine elevations, ranging from 7,000 feet to near 13,000 feet in height were found, and the evidence seems indisputable that the entire region west of the Hawaiian group has been subjected, at some remote period, to volcanic disturbances. Professor Dana, the great authority on corals, states, the range of living corals to be no more than 120 feet in depth. Where then, did the disintegrated coral, brought up from the mountain peaks 11,000 feet below the surface come from? The answer would seem to point to the former elevation of these peaks, and their gradual subsidence during the long epochs of geological action.
The theory has been that the greatest depth in the Pacific would be found in its eastern part, but so far as the question relates to the North Pacific, the line of soundings run by the Tuscarora would seem to prove to the contrary, the deepest water having been found near the Bonin Islands.
The deepest water found between San Diego and Japan viâ the Bonin Islands was 3,287 fathoms, (19,722 feet), or, about three and three quarters statute miles, and as the weight of a column of water one inch square, is about a ton for every 800 fathoms, it follows that the pressure at that enormous depth amounts to four (4) tons per square inch. The total time occupied in sounding to that great
