CARIBBEAN, kir-I-bean, SEA, a part of the Atlantic Ocean occupying a basin 750,000 square miles in area, bounded by South and Central America and the Greater and Lesser Antilles. Its perimeter is wholly mountainous. Mountain folds (continued in submarine ridges from the Greater Antilles to Honduras) mark its limits on the north and south; but the vol canic chain of the Lesser Antilles rises on the east, and the volcanoes of Central America in the remote past formed a wall separating it from the Pacific on the west. Separating it from the Atlantic are steep submarine ridges, of which the Lesser Antilles are the summits. A portion of the broad equatorial stream, which flows from east to west, from the coast of Africa to that of Brazil, enters the Caribbean between the islands at the southern end of the Antillean chain: the waters of this sea, there fore, move from east to west and northwest, and seek an exit through the Yucatan Channel —a passage 120 miles wide between Cuba and the peninsula of Yucatan. On its South Ameri can coast are the gulfs of Paria, Triste, Darien, Venezuela, Cariaco; on the west are the Mos quito Gulf and the Gulf of Honduras. But the latter is too small to allow an outflow equal to the inflow into the Caribbean; so that, after the trades have forced the equatorial water into the Caribbean basin, it must remain there a con siderable length of time, thus becoming super heated, before it passes into the Gulf of Mexico, where, owing to similar differences between the rate of inflow and outflow, the water be comes still more superheated before passing through the Florida Strait as the Gulf Stream. The main westerly current in the Caribbean, after passing through the Banks Strait, between the Mosquito Reef and Jamaica, is joined by the current of the Windward Channel. The trade-winds, blowing with a steady velocity across the Caribbean region, from east to west, make the surface of this sea much rougher than that of the Gulf of Mexico; they mitigate the tropical heat at all points where their influence is felt; and the moisture they bring from the Atlantic is precipitated in the form of abundant rains against the eastern slopes of the moun tains, both on the islands and the mainland. Hence the distinction between "windward" and "leeward' regions, insisted upon especially in the West Indies. The Gulf of Mexico, shel tered behind the Antilles and Yucatan, is prac tically a "leeward' expanse; but the summer climate of Texas and the great plains is some what modified by Caribbean trade-winds.
Recent studies of the Caribbean basin have disclosed its interesting submarine topog raphy—"a configuration which, if it could be seen, would be as picturesque in relief as the Alps or Himalayas. Nowhere can such con
trasts of relief be found within short distances. Some deeps vie in profundity with the altitudes of the near-by Andes. . . . Some of the de pressions, like the Bartlett Deep, are narrow troughs, only a few miles in width, but hun dreds of miles in length, three miles in depth, and bordered by steep precipices. . . . There are long ridges beneath the waters, which if elevated, would stand up like islands of to-day. . . . Again, vast areas are underlain by shal low banks . . . often approaching the sur face of the water, like that extending from Ja maica to Honduras. . . . The greater islands and the mainlands are bordered. in places by submerged shelves.' (From 'Cuba and Porto Rico' : see authorities below). All the islands are, then, to be regarded, from a physiographic point of view, as the "tops of a varied con figuration, which has its greatest relief beneath the sea'; and some of these submarine valleys and mountains have yielded a surprising num ber of animal forms previously unknown. Dredgings in depths of over 2,000 fathoms have brought to light new species of crustacea, and forms resembling the fossils of past geo logical epochs are taken alive in those profound marine valleys. Many phosphorescent creatures are found; in certain places "dense forests of pentacrini undulate on the bottom like aquatic plants'; on the submerged banks and in the shallows, coral polyps and mollusks are em ployed as actively now as ever, in extracting the lime carried in solution by the sea-water, to build its shells and corals which are so large a part of the rock-making material in all this region, from Yucatan to Porto Rico. The most important marine highways for Caribbean com merce are those on the north: the Windward, Anegada and Mona passages and the Yucatan Channel. The Caribbean has attained a new importance since the completion of the Panama Canal. It is now traversed by several world trade-routes directed to the Pacific through the canal. The United States has a naval base at Guantanamo Bay, Cuba; the British have bases at Bermuda and Jamaica; the Virgin Islands ac quired by the United States from Denmark in 1916 and occupied 31 March 1917, form another naval base for the defense of the canal. Sev eral steamship lines make winter cruises from New York. (For the origin of the name, see Gums). Consult Agassiz, 'The Gulf Stream' (in annual report Smithsonian Institute to July 1891, 'Washington 1893) ; Hill, of United States Geological Survey, 'Cuba and Porto Rico' (1898).
MAiuuoN WILCOX.