THE PACIFIC OCEAN HAS an area of approximately 68,767,000 square mile (178,106,000 square kilometer) with its adjacent seas; 65,329,000 square mile (169,202,000 square kilometer) without them. As the world’s largest ocean, it has the following characteristics. Volume: 160,489,000 cubic mile (674,052,000 cubic kilometer) including adjacent areas; 158,065,000 cubic mile (663,871,000 cubic kilometer) if they are not included. Average depth: with adjacent seas -13,480 foot (-4,110 meter); without them -14,038 foot (-4,280 meter). Greatest depth: -35,798 foot (-10,911 meter) in the Challenger Deep in the Mariana Trench. Width: varies from north to south reaching about 12,300 mile (19,800 kilometer) between Indonesia and the coast of Colombia in . Coastline: 84,300 mile (135,663 kilometer); adjacent areas include the Bering Sea (in the north); the Gulf of California (in the east); Ross Sea (in the south); and the Sea of Okhotsk, the Sea of Japan, and the Yellow, East China, South China, Philippine, Coral, and Tasman seas (in the west). Because the Atlantic Ocean was home to extensive exploration and commercial use long before the Pacific, research on the Pacific is not as well developed as that on the Atlantic. The Pacific basin is almost triangular in shape, narrow in the Arctic north and broad in the Antarctic south. In the west, it touches Asia and Australia, while in the east it borders the Americas. Its north to south extent between the Bering Strait in the north and Antarctica in the south is more than 9,300 mile (15,000 kilometer). In the tropics, between the Malacca Straits to Panama, the Pacific reaches its greatest width, spanning a distance of nearly 12,427 mile (20,000 kilometer). If you include all of its adjacent seas, the Pacific covers about one-third of the Earth’s surface and 40 percent of the surface area of the world’s oceans, an area greater than that of all of the continents combined. The boundary between the Pacific and Indian oceans follows a line from the Malay Peninsula through Sumatra, Java, Timor, Australia at Cape Londonderry, and Tasmania. From Tasmania to Antarctica, it follows the meridian from the South East Cape on Tasmania at 147 degrees E. The dividing line between the Atlantic and the Pacific follows the line of shallowest depth between Cape Horn and the Antarctic Peninsula. In the north, the boundary between the North Pacific and the Arctic Ocean lies along the shallow shelf of the Bering Strait that extends between the Chukchi Peninsula in eastern Siberia and the Seward Peninsula in western Alaska. There is also a boundary between the Pacific’s northern and southern zones, formed by the equatorial countercurrents that circulate just north of the equator in an area known as the Intertropical Convergence Zone (ITCZ).