Persian Gulf. An arm of the Indian Ocean which penetrates between Arabia and Persia to the extent of 650 English miles in a general north-westerly direction. Its breadth varies from 55 miles at the mouth to 250 miles, and the area is estimated at 77,450 sq. m., not including the islands, which are scattered over the western half, or lie close inshore along the eastern side. The chief of these islands are Ormuz, at the mouth; Kishm, 810 sq. m. in extent; and the Bahrein Islands. The Great Pearl Bank stretches along the western side from Ras Hassan to nearly half-way up the gulf. The coast is mostly formed of calcareous rocks. On the Arabian side it is low and sandy, occasionally broken by mountains and cliffs; while on the Persian side it is higher and abrupt, with deep water close inshore, owing to the mountain-ranges of Fars and Laristan running close to the water's edge. The islands are partly of limestone and partly of ironstone, and are generally destitute of springs, barren, desolate, and presenting numerous traces of volcanic eruptions. Except the Shat-el-Arab (see EUPHRATES), the Persian Gulf receives only insignificant streams. Its eastern side presents abundance of good anchorage, either in the numerous bays or in the lee of islands. The greater portion of its southern shores now belongs to the Imam of Muscat, while the whole of the northern shore belongs to Persia. The order of the periodic currents in this gulf is precisely the reverse of that of the Red Sea (q.v.) currents, as they ascend from May to October, and descend from October to May. The greatest depth does not exceed 50 fathoms; and Dr John Murray calculates its total cubic contents at 2200 cubic miles of water. Oriental geographers give to this gulf the name of the 'Green Sea,' from a remarkable strip of water, of a green colour, lying along the Arabian coast.
The submarine telegraph cables belonging to the government of India, and forming part of the system of the Indo-European Telegraph, pass through the whole length of the Persian Gulf, from Fao at the mouth of the Shat-el-Arab, where they connect with the Turkish lines, to Bushire, where they connect with the Persian, and thence to Jask, Gwadur, and Kurrachee, where they connect with the general telegraph system of India. Among the ports are Bender Abbas (q.v.), Bushire (q.v.), and Lingah (pop. 8000).