IV.—Oceanic ‘Deeps’

Extract

One of the most characteristic features of the great oceans is the presence of what have been aptly termed ‘deeps,’ enormous depressions in the ocean bottoms. Having in my “Evolution of Earth Structure” discussed their distribution and probable origin, I was naturally attracted by the notice in Nature of the surveys of the vessel “Edi” and the cable-ship “Stephan” during 1903 and 1905 in the western and south-western parts of the Pacific Ocean. Drs. G. Shott and P. Perlewitz, in a paper recently issued in the Archiv der deutschen Seewarte, taking into consideration previous work by U.S. ship “Hero” and of the German vessel “Planet,” consider that these soundings throw a great deal of new light on the configuration of the sea bottom in those regions. They state that the troughs forming the deeps are usually about 10 miles wide, excepeting the Guam deep, which is as much as 20 across. The most interesting statement to me is that in their opinion the troughs are the result of subsidence occurring on an enormous scale along lines of fracture, and that is probable the disturbances which produced these structures are comparatively recent.