Just offshore from the small town of Moss Landing, Calif.—once an important West Coast fishing hub and now a center of oceanographic research—stretches one of the country’s most magnificent but little-known geologic features: Monterey Canyon. About the same size as the Grand Canyon in Arizona, its main channel is nearly 300 miles long. (The deepest part of the Grand Canyon is deeper, in comparison, but by just 430 feet). The Monterey Bay Aquarium Research Institute (MBARI) sits on the coast near the mouth of Monterey Canyon. The map reveals many characteristics that make this submarine canyon different than the Grand Canyon.