California, Gulf of

California, Gulf of, or Sea of Cortés, arm of the Pacific Ocean, c.700 mi (1,130 km) long and 50 to 130 mi (80–209 km) wide, NW Mexico; separates Baja California from the Mexican mainland. The gulf is part of a depression in the earth's surface that extends inland to the Coachella Valley, S Calif. The Imperial Valley and the Salton Sea, once part of the gulf, have been cut off from it by the growth of the Colorado River delta. The gulf deepens from north to south; its greatest depth is c.8,500 ft (2,590 m). The coastline is irregular, with numerous islands; Tiburon, inhabited by aboriginal tribes, is the largest. Storms and tidal currents hinder navigation in the gulf. Once a rich commercial and sport fishing ground, the gulf now suffers from overfishing. The region is a developing tourist center; La Paz, Guaymas, and Mazatlán are major cities. The area was first explored in 1538 by the Spaniard Francisco de Ulloa.

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California, Gulf of 

a gulf of the Pacific Ocean along the western coast of North America. It is separated from the ocean by the peninsula of Lower California and is in effect a semi-enclosed sea. Length, 1, 240 km; maximum width, 220 km; area, 177, 000 sq km; average depth, 818 m. Depths increase from the head (34 m) to the mouth (3, 292 m, the greatest depth of the gulf)- There are many islands, the largest of which are Tiburon and Angel de la Guarda. The climate is subtropical. Surface currents circulate counterclockwise. Winter temperatures vary from 15°C in the northwest to 21°C in the southeast, and in the summer they rise to 28°C. The salinity of the water is 35.1-35.5 parts per thousand in the north (near the mouth of the Colorado River), diminishing to 30 parts per thousand. Tides are irregular and occur twice daily (up to 2.9 m). Fish in the Gulf of California include tuna, flounder, mackerel, and sea bass. Accumulations of Ciliata infusoria cause tinting of the water in various shades of red. The principal port is Guaymas (Mexico).