California, Gulf

California, Gulf of

 or Sea of Cortés

Gulf separating Baja California from the rest of Mexico. Its area is about 59,000 sq mi (153,000 sq km). Its waters were coloured by red plankton when 16th-century Spanish explorers named it Mar Bermejo (“Vermilion Sea”). Some geologists hold that the gulf is structurally part of the Pacific Ocean; others claim Baja California is pulling away from the continent as it moves north along the San Andreas Fault, allowing the gulf to form.