the world's largest and deepest ocean, lying between Asia and Australia and North and South America: almost landlocked in the north, linked with the Arctic Ocean only by the Bering Strait, and extending to Antarctica in the south; has exceptionally deep trenches, and a large number of volcanic and coral islands. Area: about 165 760 000 sq km (64 000 000 sq miles). Average depth: 4215 m (14 050 ft). Greatest depth: Challenger Deep (in the Marianas Trench), 11 033 m (37 073 ft). Greatest width: (between Panama and Mindanao, Philippines) 17 066 km (10 600 miles)