Gulf of California
The Gulf of California was originally named the Sea of Cortez by Spanish explorers and is still known locally by that name. It marks the boundary between the North American and Pacific plates. The peninsula of Baja California lies on the Pacific Plate and is moving northwest, away from Mexico, at about 2 in (5 cm) each year. To the north, large earthquakes are quite frequent along the San Andreas Fault. The waters of the gulf support a rich ecosystem and a healthy commercial fishery. In addition to the native species, migratory visitors include humpback whales, manta rays, and leatherback turtles. The California gray whale completes the longest migration of any mammal, spending a few weeks each year in breeding grounds off Baja California, before returning to the Bering Sea, 5,000 miles (8,000 km) away.