Off which U.S. coastal area can you find an underwater canyon that rivals the Grand Canyon?

Monterey Bay, in the Pacific Ocean, lies along California’s Big Sur and central coasts, south of the major California cities of San Francisco and San Jose. It stretches 275 miles (444 km) from the Golden Gate Bridge in the north, to the Monterey peninsula in the south.

The Monterey Bay National Marine Sanctuary, established in 1992, protects one of the world’s most diverse marine ecosystems. More than 500 types of fish, 180 species of seabirds and 36 marine mammal species grace the sanctuary’s waters. In addition to abundant sea life, the area is also “home” to Monterey Canyon, the deepest submarine canyon on the west coast of the U.S.

Counting the water that lies above its’ walls, Monterey Canyon is roughly 6,000 feet (1,829 m) deep, thus rivaling the Grand Canyon for depth. The average depth of the Grand Canyon is just over a mile (5,280 feet or 1,609 meters) but at its deepest point, it is 6,093 feet (1,857 meters) deep. The depth of the water above the actual walls of the Monterey Canyon is about 430 feet (131 m). However, the depth of both canyons is constantly subject to change, due to river or ocean currents, and sedimentary deposits.

Also part of the Monterey Bay National Marine Sanctuary is the Davidson Seamount, an underwater volcano. From base to crest, the seamount is 7,480 ft (2,280 m) tall, yet its summit is still 4,101 ft (1,250 m) below the sea surface.