RED SEA, or ARABIAN GULF (an cient, Mare Rubrum, More Erythreeinti, or Sinus Arabicus; Arabic, a branch of the Indian Ocean, extending from the Strait of Bab-el-Mandeb, in a north-northwest direction between Arabia on the east, and Abyssinia, Nubia and Egypt on the west, and connected with the Mediterranean on the north by the canal, about 100 miles long, across the Isthmus of Suez. The Red Sea is a compartively nar row expanse, 1,450 miles long with a maximum breadth on the tropic of Cancer of 200 miles and a general average of about 180 miles, but diminishing gradually at its south and north ex tremities; at the former, across the strait it has a width of only 141/2 miles, further subdivided by the island of Perium into two channels, a larger on the east, of 11 miles, and a less on the west of one and one-half miles, and forking at the latter into two branches, the one of which, forming the Gulf of Akaba, penetrates north by east into Arabia for about 100 miles, with an average breadth of about 15 miles; while the other, forming the Gulf of Suez, follows the general direction of the sea, and penetrates be tween Arabia and Egypt for about 200 miles, with an average breadth of about 20 miles. In the fork between these two branches is the celebrated Mount Sinai, or Jebel Musa (Mount of Moses). To the biblical student the Red Sea possesses considerable interest, from the ac count of its miraculous passage by the children of Israel • when journeying from Egypt. The place at , which they crossed the sea was the Gulf of •Suez at its northern extremity, but opinions 4iffer as to the exact point of transit, some maintaining that it was in the neighbor hood of the town of Suez, and others that it was about 18 miles farther south, at the mouth of the Wady Tuarik The marine temperature ranges from 70° to 94° F.
The climate is tropical and depressing; both shores of the Red Sea east and west consist of a low tract, mostly sandy, though sometimes swampy, varying in width from 10 to 30 miles, and suddenly terminated by the abutments of a lofty table-land of 3,000 feet to 6,000 feet high. The Red Sea may thus be considered as occupying the bottom of an im mense longitudinal valley, which probably at one time extended between the table-lands without interruption, but has since been partially filled up by coral-workings, which; extending in paral lel lines at a short distance from either coast, have subdivided the .sea into three different
channels, and have also studded its shores with numerous small islands. In the main channel the depth reaches in one place 1,200 fathoms, but diminishes toward the extremities, where the depth in general does not exceed from 40 to 50 fathoms; the mean depth may be taken at 375 fathoms.
In the Gulf of Suez, which in earlier times is supposed to have extended considerably far ther north, this depth gradually decreases to 30 fathoms, and still continues to shoal, till at the harbor of Suez it amounts to only three fathoms; in the Gulf of Akaba, on the contrary, the depth of the main channel is fully main tained, and in some places even exceeded. The currents of the Red Sea are the result of pre vailing winds. These winds, whether proceed ing either directly north or. south, affect only the main body of the sea, and leave a consider able belt along the coasts subject to alterna tions of land and sea breezes, and not unfre quently to sudden squalls. The chief dangers to navigation arise from the number of shallow reefs, of the presence of which no intimation is given, as the sea never breaks upon them. This absence of breakers is accounted for by the porous nature of the coral, which offers so little resistance that the sea diffuses through it without commotion, as if it were passing through a sieve. The principal harbors of the Red Sea are, in the African Coast, Suez, Kos seir, Suakin and Massowa; and on the Arabian Coast, Jedda (the port of Mecca), Hodeida and Mocha. The trade from shore to shore is not of much importance, consisting chiefly of the transport of pilgrims and some grain from Egypt; but the trade up and down the sea, be tween Europe and the East Indies, has become very large since the construction of the great ship canal across the Isthmus of Suez.
A telegraphic cable enters the Red Sea at Suez, passes down to Kosseir on its western shore, thence to Suakin on the same side, about lat. 19° 10' N., and then proceeds in a south southeastern direction close to the island of Perim, and out into the Indian Ocean by the Strait of Bab-el-Mandeb, and arrives at Aden (q.v.).