Submarine Valleys and Cafions off American Coast 
No one has offered evidence showing that the cafions and valleys crossing the Continental Shelf or 
the island plateaus are the remains of open fissures made by earth movements. 
There are basins and troughs in the ocean deep about which little is known,} but the occurrence of 
terraces upon their upper slopes, with dissecting valleys and gorges, opening into embayments, show that 
their sinking was completed only at a later date, although the basins were pre-existent, while their 
upper slopes formed land-features. 
Even in Northern regions the origin of deep valleys by glacial erosion is disputed ; but their 
occurrence in low latitudes must remove the possibility of this hypothesis being applied here to these 
submarine cafions. 
From all of these features investigated on both sides of the Atlantic, and their occurrence in other 
parts of the world, there seems no possible escape from the conviction that there have been great changes 
of level in recent geological times, amounting to thousands of feet. Such naturally affected the climatic 
conditions, and the distribution and extinction of animal and vegetable life. While these movements 
occurred in late geological times, they were of long duration in years. The sea-level may have changed,? 
and the land also was deformed over large areas. 
There were minor oscillations subsequent to the great movements, which are not considered here. 
Some of the phenomena already described may yet be separated more precisely as to their date. But the 
beginnings of a new science have been made. To this, Europe and America furnish complementary parts 
on the two sides of the Atlantic, with only such differences as would be expected from the variation of 
land-features ; but the high plateaus of the Western Hemisphere, surmounted by the newer geological 
formations, more completely reproduce the submarine features bordering the continent, on a clearer and 
broader scale than is found in Western Europe.? Also the distribution of biological forms in America 
confirms the physiographic evidence of changes of level, to the extent of at least more than a mile and a 
quarter, during the early Glacial period or immediately before. 
Utilities —Pure science commonly leads to its economic application ; the investigation of the 
submarine valleys is no exception. Professor Hull has referred to the importance of the charts in laying 
out oceanic cables ; the following cases illustrate their importance for purposes of navigation. 
Professor Davidson mentions that two vessels were lost on the Pacific coast during a violent gale. The 
anchors were unfortunately dropped into submarine channels, where no anchorage was obtainable, and the 
ships were blown upon the adjacent coast and wrecked. Had the captains known of the existence of these 
channels they could have saved their ships by sailing at right angles away from them, and found anchorage. 
During the prevalence of heavy fogs, the wise captains approaching New York drop the sounding- 
line to great depths, and hunt for a submarine Hudson Caiion, so as to establish their position, after 
making a dead run. 
Professor William Libbey also found that the colder waters of the Hudson Cajfion have affected the 
migration and destruction of fishes. 
Time will doubtless bring to light other uses to which this branch of oceanic physiography can be 
applied. 
The scope of this paper relates to North America only, but investigation of the submarine valleys 
off the coast of South America have been made by Prof. J.C. Branner, to whose works the reader is referred.’ 
1 The basin of the Gulf of Mexico is 12,000 feet deep, that of the Caribbean Sea 15,000 feet, while the trough in the Sea of Honduras, 
between Cuba and Jamaica, reaches 18,000 feet. The basin north of Puerto Rico is the deepest known depression of the Atlantic, discovered to 
27,366 feet. 
2 Lyell has discussed this question of the permanence of the sea-level, and concludes that it remains permanent, in that its surface is approximately 
everywhere at the same distance from the centre of the earth. 
3 In a plateau region of Central France, named the “ Causses,” magnificent cafions occur, reaching to 1200 feet in depth, but their features are 
more mature than many in Mexico, where younger forms may also be seen. 
4 “The Stony Reefs of Brazil: their Geological and Geographical Relations,” by J. C. Branner, Geol. Series VII., Mus. Comp. Zool. Harvard, 
pp. 1-285 (1901-4). Also “ The Geography of North-Eastern Bahia,” Geog. Fourn. vol. xxxviii. Nos. 2-3 (1911). 
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