Pacific Ocean 1 Pacific Ocean The Pacific Ocean Earth's oceans • Arctic • Pacific • Atlantic • Indian • Southern World Ocean The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, bounded by Asia and Australia in the west, and the Americas in the east. At 165.25 million square kilometres (63.8 million square miles) in area, this largest division of the World Ocean – and, in turn, the hydrosphere – covers about 46% of the Earth's water surface and about one-third of its total surface area, making it larger than all of the Earth's land area combined.[1] The equator subdivides it into the North Pacific Ocean and South Pacific Ocean, with two exceptions: the Galápagos and Gilbert Islands, while straddling the equator, are deemed wholly within the South Pacific.[] The Mariana Trench in the western North Pacific is the deepest point in the world, reaching a depth of 10,911 metres (35,797 ft).[2] Pacific Ocean 2 The eastern Pacific Ocean was first sighted by Europeans in the early 16th century when Spanish explorer Vasco Núñez de Balboa crossed the Isthmus of Panama in 1513 and discovered the great "southern sea" which he named Mar del Sur. The ocean's current name was coined by Portuguese explorer Ferdinand Magellan during the Spanish expedition of the world in 1521, as he encountered favourable winds on reaching the ocean. He therefore called it Mar Pacifico in Portuguese, meaning "peaceful sea".[3] History Important human migrations occurred in the Pacific in prehistoric times, most notably those of the Polynesians from the Asian edge of the ocean to Tahiti, Hawaii, New Zealand, Easter Island and possibly even America.[] The east side of the ocean was discovered by Spanish explorer Vasco Núñez de Balboa in the early 16th century. Balboa's expedition crossed the Isthmus of Panama and reached the Pacific Ocean in 1513.[] He named it Mar del Sur (South Sea). Later, Portuguese explorer Ferdinand Magellan sailed the Pacific on a Spanish expedition of Maris Pacifici by Ortelius (1589). One of the first printed maps to show the Pacific Ocean; see also world circumnavigation from 1519 to 1522. Magellan called the ocean [4] Waldseemüller map (1507). Pacífico or "Pacific" because, after sailing through the stormy seas off Cape Horn, he was surprised how calm the waters became. Although Magellan himself died in the Philippines in 1521, Spanish navigator Juan Sebastián Elcano led the expedition back to Spain across the Indian Ocean and round the Cape of Good Hope, completing the first world circumnavigation in 1522.[5] In 1564, five Spanish ships consisting of 379 explorers crossed the ocean from Mexico led by Miguel López de Legazpi and sailed to the Philippines and Mariana Islands.[] For the remainder of the 16th century, Spanish influence was paramount, with ships sailing from USS Lexington under air attack on 8 May 1942 Mexico and Peru across the Pacific Ocean to the Philippines, via during the Battle of the Coral Sea. Guam, and establishing the Spanish East Indies. The Manila galleons operated for two and a half centuries linking Manila and Acapulco, in one of the longest trade routes in history. Spanish expeditions also discovered Tuvalu, the Marquesas, the Solomon Islands and New Guinea in the South Pacific. Later, in the quest for Terra Australis, Spanish explorers in the 17th century discovered the Pitcairn and Vanuatu archipelagos, and sailed the Torres Strait between Australia and New Guinea, named after navigator Luís Vaz de Torres. Dutch explorers, sailing around southern Africa, also engaged in discovery and trade; Abel Janszoon Tasman discovered Tasmania and New Zealand in 1642.[6] The 18th century marked the beginning of major exploration by the Russians in Alaska and the Aleutian Islands. Spain also sent expeditions to the Pacific Northwest reaching Vancouver Island in southern Canada, and Alaska. The French explored and settled Polynesia, and the British made three voyages with James Cook to the South Pacific and Australia, Hawaii, and the North American Pacific Northwest. In 1768 Pierre-Antoine Véron, a young astronomer accompanying Louis Antoine de Bougainville on his voyage of exploration, established the width of the Pacific with precision for the first time in history.[] One of the earliest voyages of scientific exploration was organized by Spain in the Malaspina Expedition of 1789-1794. It sailed vast areas of the Pacific, from Cape Horn to Alaska, Guam and the Philippines, New Zealand, Australia and the South Pacific. Pacific Ocean 3 Growing imperialism during the 19th century resulted in the occupation of much of Oceania by other European powers, and later, Japan and United States. Significant contributions to oceanographic knowledge were made by the voyages of HMS Beagle in the 1830s, with Charles Darwin aboard; HMS Challenger during the 1870s; the USS Tuscarora (1873–76); and the German Gazelle (1874–76). Although the United States gained control of Guam and the Philippines from Spain in 1898,[] Japan controlled most of the western Pacific by 1914 and occupied many other islands during World War II. However, by the end of that war, Japan was defeated and the U.S. Pacific Fleet The Bathyscaphe Trieste, before her record dive to the bottom of the Mariana Trench, 23 January was the virtual master of the ocean. Since the end of World War II, 1960. many former colonies in the Pacific have become independent states. Geography The Pacific separates Asia and Australia from the Americas. It may be further subdivided by the equator into northern (North Pacific) and southern (South Pacific) portions. It extends from the Antarctic region in the South to the Arctic in the north.[1] The Pacific Ocean encompasses approximately one-third of the Earth's surface, having an area of 165.2 million square kilometres (63.8 million square miles) —significantly larger than Earth's entire landmass of some 150 million square kilometres (58 million square miles).[7] Extending approximately 15,500 kilometres (9,600 mi) Island nations and territories of the Pacific from the Bering Sea in the Arctic to the northern extent of the circumpolar Southern Ocean at 60°S (older definitions extend it to Antarctica's Ross Sea), the Pacific reaches its greatest east-west width at about 5°N latitude, where it stretches approximately 19,800 kilometres (12,300 mi) from Indonesia to the coast of Colombia – halfway across the world, and more than five times the diameter of the Moon.[] The lowest known point on Earth—the Mariana Trench—lies 10,911 metres (35,797 ft or 5,966 fathoms) below sea level. Its average depth is 4,028~4,188 metres (14,000 ft or Sunset over the Pacific Ocean as seen from the International Space Station. Anvil tops of 2,333 fathoms).[1] thunderclouds are also visible. Due to the effects of plate tectonics, the Pacific Ocean is currently shrinking by roughly an inch per year (2–3 cm/yr) on three sides, roughly averaging 0.2 square miles (0.52 km2) a year. By contrast, the Atlantic Ocean is increasing in size.[8][] Along the Pacific Ocean's irregular western margins lie many seas, the largest of which are the Celebes Sea, Coral Sea, East China Sea, Philippine Sea, Sea of Japan, South China Sea, Sulu Sea, Tasman Sea, and Yellow Sea. The Strait of Malacca joins the Pacific and the Indian Oceans on the west, and Drake Passage and the Strait of Magellan link the Pacific with the Atlantic Ocean on the east. To the north, the Bering Strait connects the Pacific with the Pacific Ocean 4 Arctic Ocean.[] As the Pacific straddles the 180th meridian, the West Pacific (or western Pacific, near Asia) is in the Eastern Hemisphere, while the East Pacific (or eastern Pacific, near the Americas) is in the Western Hemisphere.[] For most of Magellan's voyage from the Strait of Magellan to the Philippines, the explorer indeed found the ocean peaceful. However, the Pacific is not always peaceful. Many tropical storms batter the islands of the Pacific.[9] The lands around the Pacific Rim are full of Storm in Pacifica, California volcanoes and often affected by earthquakes.[] Tsunamis, caused by underwater earthquakes, have devastated many islands and in some cases destroyed entire towns.[] Bordering countries and territories Sovereign nations • Australia • Brunei • Cambodia • Canada • Chile • China • Colombia • Costa Rica • Ecuador • El Salvador • Federated States of Micronesia • Fiji • Guatemala • Honduras • Indonesia • Japan • Kiribati • North Korea • South Korea • Malaysia • Marshall Islands • Mexico • Nauru • New Zealand • Nicaragua • Palau • Panama • Papua New Guinea • Peru • Philippines • Russia Pacific Ocean 5 • Samoa • Singapore • Solomon Islands • Taiwan1 • Thailand • Timor-Leste • Tonga • Tuvalu • United States • Vanuatu • Vietnam 1 The status of Taiwan is disputed. For more information, see political status of Taiwan. Territories • American Samoa (US) • Baker Island (US) • Cook Islands (New Zealand) • Coral Sea Islands (Australia) • Easter Island (Chile) • French Polynesia (France) • Guam (US) • Hong Kong (China) • Howland Island (US) • Jarvis Island (US) • Johnston Island (US) • Kingman Reef (US) • Macau (China) • Midway Atoll (US) • New Caledonia (France) • Niue (New Zealand) • Norfolk Island (Australia) • Northern Mariana Islands (US) • Palmyra Atoll (US) • Pitcairn Islands (UK) • Tokelau (New Zealand) • Wallis and Futuna (France) • Wake Island (US) Pacific Ocean 6 Landmasses and islands The islands entirely within the Pacific Ocean can be divided into three main groups known as Micronesia, Melanesia and Polynesia. Micronesia, which lies north of the equator and west of the International Date Line, includes the Mariana Islands in the northwest, the Caroline Islands in the centre, the Marshall Islands to the west and the islands of Kiribati in the southwest.[][] Melanesia, to the southwest, includes New Guinea, the world's second largest island after Greenland and by far the largest of the Pacific Micronesia, Melanesia and Polynesia islands.