Persian Gulf as "The Northwestern limit of Gulf of Oman". This limit is defined as "A line joining Ràs Limah (25°57'N) on the coast of Arabia and Ràs al Kuh (25°48'N) on the coast of Iran (Persia)". The gulf is connected to Indian Ocean through Strait of Hormuz. Writing the water balance budget for the Persian Gulf, the inputs are river discharges from Iran and Iraq (estimated to be 2000 cubic meters per second), as well as precipitation over the sea which is around 180mm/year in Qeshm Island. The evaporation of the sea is high, so that after considering river discharge and
Persian Gulf naming dispute the head of the Persian Gulf. This coincided with the early mapmaking efforts of Gerard Mercator, whose 1541 terrestrial globe attempts to give the most up-to-date information, naming the gulf "Sinus Persicus, nunc Mare de Balsera" ("Persian Gulf, now Sea of Basra"). However, on his world map of 1569, the name is changed to "Mare di Mesendin" (after the peninsula Ra's Musandam, in modern-day Oman), while his rival Abraham Ortelius, for the world atlas of 1570, opted for "Mare El Catif, olim Sinus Persicus" (after the Arabian port of Al Qatif), but labelled the entrance to the gulf the present-day