DEPTH OF THE OCEAN.

Wanganui Chronicle, Volume L, Issue 12765, 17 June 1911, Page 12 (Supplement)

DEPTH OF THE OCEAN.

SAID TO BE FIVE MILES IN PLACES.

Tho ocean has been sounded in nearly all directions with modern applijinces, and these soundings show that tho floor of tho ocean consists of vast undulating plains, lying at an average depth of about two and a half miles beneath the surface of the waves, says Sir John Murray in "Harper's Magazine." In some places-huge ridges and cones rise from those submerged plains to within a few hundred fathoms of the sea surface as volcanic islands and coral atolls. The greatest depth hitherto recorded h in the Challenger ■ (or Nero) Deep, in the North Pacific—s2s9 fathoms. If Mount Everest were played in this deep* 26G0f0 of water would roll over tho peak of this, the highest moutain in the world. The greatest depth in the Atlantic is in the Nares Deep, between the West Indies and Bermuda — 4662 fathoms. The greatest depth irt i.he Indian Ocean is 3328 fathoms, in the Wharton Deep, between Christmas Island and the coast of Java.

We now know s(< of these deeps where the depth exceeds three geographical miles, 10 ureas where the depth exceeds four miles and four places wheru it exceeds five miles.

Tho sea. as all the world knows, is salt. It is saltest where strong dry -winds blow across the surface, as,, for instance, in tho trade wind regions and in the Mediterranean and Red Sea. It is less salt toward tho poles and in the deeper layers of tho ocean. It has long been known that the very salt water of tho Mediterranean flows in an nndercnnviit outward through the Strait of Gibraltar, and thus affects tho salinity of the deeper waters of the Atlantic over a wide area.

Although tho amount of salt in sea water varies, the composition of sea s.-ilts remnin< vary constant; slight differences hrvo, however, been noticed along; the continental coasts, in the polar regcions an*d in tho water in direct contact with deep sea deposits.

Tho temperature of ocean water varies at the surface from 23deg. Fahr. fit tho poles to more than BOdeg. Fahr. in the tropics. The cold water toward tho nolos has an annual variation of less than lOdeg. Fahr. at any one spot, ?rid the warns water of tho tronies also has an annual variation of less than TOde^ Fahr. in a band that nearly encircles the earth ; this is tho region of ooral reefs and atolls.

Between »the~e regions of smrill annual variation there are two bands surrounding the i?nrfch were the annual variation is creator, and may exceed in certain regions 40des. Fahr. at any one spot.