The Pacific plate, shown in pale yellow

The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At 105 million square kilometres, it is the largest tectonic plate.

The north-eastern side is a divergent boundary with the Explorer Plate, the Juan de Fuca Plate and the Gorda Plate forming respectively the Explorer Ridge, the Juan de Fuca Ridge and the Gorda Ridge. In the middle of the eastern side is a transform boundary with the North American Plate along the San Andreas Fault, and a boundary with the Cocos Plate. The south-eastern side is a divergent boundary with the Nazca Plate forming the East Pacific Rise.

The southern side is a divergent boundary with the Antarctic Plate forming the Pacific-Antarctic Ridge.

The western side, the plate is bounded by the Okhotsk Plate at the Kuril-Kamchatka Trench and the Japan Trench, forms a convergent boundary by subducting under the Philippine Sea Plate creating the Mariana Trench, has a transform boundary with the Caroline Plate, and has a collision boundary with the North Bismarck Plate.

In the south-west, the Pacific Plate has a complex but generally convergent boundary with the Indo-Australian Plate, subducting under it north of New Zealand forming the Tonga Trench and the Kermadec Trench. The Alpine Fault marks a transform boundary between the two plates, and further south the Indo-Australian Plate subducts under the Pacific Plate forming the Puysegur Trench. The southern part of Zealandia, which is to the east of this boundary, is the plate's largest block of continental crust.

The northern side is a convergent boundary subducting under the North American Plate forming the Aleutian Trench and the corresponding Aleutian Islands.

The Pacific Plate contains an interior hot spot forming the Hawaiian Islands.

Hillis and Müller are reported to consider the Bird's Head Plate to be moving in unison with the Pacific Plate.^[1] Bird considers them to be unconnected.^[2]

Paleo-geology of the Pacific Plate[link]

The Pacific Plate has the distinction of showing one of the largest areal sections of the oldest members of seabed geology being entrenched into eastern Asian oceanic trenches. A geologic map of the Pacific Ocean seabed shows not only the geologic sequences, and associated Ring of Fire zones on the ocean's perimeters, but the various ages of the seafloor in a stair-step fashion, youngest to oldest, the oldest being consumed into the Asian oceanic trenches. The oldest member disappearing by way of the Plate Tectonics cycle is early-Cretaceous (145 to 137 million years ago).^[3]

All maps of the Earth's ocean floor geology show ages younger than 145 million years, only about 1/40 of the Earth's 4.55 billion year history.

References[link]

External links[link]

• Age of the Ocean Floor

v t e Tectonic plates Major African · Antarctic · Eurasian · Indo-Australian · North American · Pacific · South American Minor Arabian · Caribbean · Cocos · Juan de Fuca · Nazca · Philippine · Scotia Other Aegean Sea · Altiplano · Amurian · Anatolian · Apulian · Australian · Balmoral Reef · Banda Sea · Bird's Head · Burma · Capricorn · Caroline · Conway Reef · Easter · Explorer · Falklands · Futuna · Galapagos · Gonâve · Gorda · Greenland · Halmahera · Iberian · Indian · Iranian · Juan Fernández · Kerguelen · Kermadec · Kula · Madagascar · Manus · Maoke · Mariana · Molucca Sea · New Hebrides · Niuafo'ou · North Andes · North Bismarck · North Galapagos · Nubian · Okhotsk · Okinawa · Panama · Pelso · Philippine Mobile Belt · Rivera · Sangihe · Seychelles · Shetland · Solomon Sea · Somali · South Bismarck · South Sandwich · Sri Lanka · Sunda · Timor · Tisza · Tonga · Woodlark · Yangtze All List of tectonic plates

The Pacific Ocean

Earth's oceans (World Ocean)
Arctic Ocean Atlantic Ocean Indian Ocean Pacific Ocean Southern Ocean

This video was taken by the crew of Expedition 29 on board the ISS on a pass from the Middle East to the South Pacific 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 165.2 million square kilometres (64.1 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.^[2] 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).^[3]

The eastern Pacific Ocean was first sighted by Europeans early in the 16th century. Spanish explorer Vasco Núñez de Balboa crossed the Isthmus of Panama in 1513 and named it Mar del Sur (South Sea). The ocean's current name was given by Portuguese explorer Ferdinand Magellan during the Spanish expedition of world circumnavigation in 1521, who encountered favourable winds as he reached the ocean and called it Mar Pacifico in Portuguese, meaning "peaceful sea".^[4]

Overview[link]

Sunset over the Pacific Ocean as seen from the International Space Station. Anvil tops of thunderclouds are also visible.

The Pacific Ocean encompasses approximately one-third of the Earth's surface, having an area of 165.2 million square kilometres (64.1 million square miles) —significantly larger than Earth's entire landmass, with room for another Africa to spare.

Extending approximately 15,500 kilometres (9,600 mi) 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 2,333 fathoms).^[1]

The Pacific Ocean is currently shrinking due to plate tectonics, while the Atlantic Ocean is increasing in size, by roughly an inch per year (2–3 cm/yr) on 3 sides, roughly averaging 0.2 square miles (0.52 km²) a year.

Storm in Pacifica, California

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 Straits of Magellan link the Pacific with the Atlantic Ocean on the east. To the north, the Bering Strait connects the Pacific with the 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. The lands around the Pacific Rim are full of volcanoes and often affected by earthquakes. Tsunamis, caused by underwater earthquakes, have devastated many islands and in some cases destroyed entire towns.

Extent[link]

Water characteristics[link]

Sunset in Monterey County, California, U.S.

The volume of the Pacific Ocean is approximately 622 million cubic km. Water temperatures in the Pacific vary from freezing in the poleward areas to about 30 °C (86 °F) near the equator. Salinity also varies latitudinally. The water near the equator is less salty than that found in the mid-latitudes because of abundant equatorial precipitation throughout the year. Poleward of the temperate latitudes salinity is also low, because little evaporation of seawater takes place in these frigid areas.

The motion of Pacific waters is generally clockwise in the Northern Hemisphere (the North Pacific gyre) and counter-clockwise in the Southern Hemisphere. The North Equatorial Current, driven westward along latitude 15°N by the trade winds, turns north near the Philippines to become the warm Japan or Kuroshio Current.

Turning eastward at about 45°N, the Kuroshio forks and some waters move northward as the Aleutian Current, while the rest turn southward to rejoin the North Equatorial Current. The Aleutian Current branches as it approaches North America and forms the base of a counter-clockwise circulation in the Bering Sea. Its southern arm becomes the chilled slow, south-flowing California Current.

The South Equatorial Current, flowing west along the equator, swings southward east of New Guinea, turns east at about 50°S, and joins the main westerly circulation of the Southern Pacific, which includes the Earth-circling Antarctic Circumpolar Current. As it approaches the Chilean coast, the South Equatorial Current divides; one branch flows around Cape Horn and the other turns north to form the Peru or Humboldt Current.

Geology[link]

The Pacific is ringed by many volcanoes and oceanic trenches

Ulawun stratovolcano situated on the island of New Britain, Papua New Guinea

The ocean was mapped by Abraham Ortelius; he called it Maris Pacifici because of Ferdinand Magellan, who sailed the Pacific during his circumnavigation from 1519 to 1522 and said that it was much more calm than the Atlantic.

The andesite line is the most significant regional distinction in the Pacific. It separates the deeper, mafic igneous rock of the Central Pacific Basin from the partially submerged continental areas of felsic igneous rock on its margins. The andesite line follows the western edge of the islands off California and passes south of the Aleutian arc, along the eastern edge of the Kamchatka Peninsula, the Kuril Islands, Japan, the Mariana Islands, the Solomon Islands, and New Zealand's North Island.

The dissimilarity continues northeastward along the western edge of the Andes Cordillera along South America to Mexico, returning then to the islands off California. Indonesia, the Philippines, Japan, New Guinea, and New Zealand lie outside the Andesite Line.

Within the closed loop of the Andesite Line are most of the deep troughs, submerged volcanic mountains, and oceanic volcanic islands that characterize the Pacific basin. Here basaltic lavas gently flow out of rifts to build huge dome-shaped volcanic mountains whose eroded summits form island arcs, chains, and clusters. Outside the Andesite Line, volcanism is of the explosive type, and the Pacific Ring of Fire is the world's foremost belt of explosive volcanism. The Ring of Fire is named after the several hundred active volcanoes that sit above the various subduction zones.

The Pacific Ocean is the only ocean which is almost totally bounded by subduction zones. Only the Antarctic and Australian coasts have no nearby subduction zones.

Geological history[link]

The Pacific Ocean developed from the Panthalassic Ocean following the breakup of Pangaea. There is no firm date for when the changeover occurred, as the replacement of the sea bed is a continuous process, though reconstruction maps often change the name from Panthalassic to Pacific around the time the Atlantic Ocean began to open.^[5][6][7] The Panthalassic Ocean first opened 750 million years ago at the breakup of Rodinia,^[7] but the oldest Pacific Ocean floor is only around 180 Ma old.^[8]

Seamount chains[link]

The Pacific Ocean contains several long seamount chains, formed by hotspot volcanism. These include the Hawaiian – Emperor seamount chain and the Louisville seamount chain.

Landmasses and islands[link]

Tahuna maru islet, French Polynesia.

The largest landmass entirely within the Pacific Ocean is the island of New Guinea— the second largest island in the world. Almost all of the smaller islands of the Pacific lie between 30°N and 30°S, extending from Southeast Asia to Easter Island; the rest of the Pacific Basin is almost entirely submerged. During the last glacial period, New Guinea was part of Australia so the largest landmass would have been Borneo–Palawan.

The great triangle of Polynesia, connecting Hawaii, Easter Island, and New Zealand, encompasses the island arcs and clusters of the Cook Islands, Marquesas Islands, Samoa, Society, Tokelau, Tonga, Tuamotu, Tuvalu and the Wallis and Futuna islands.

North of the equator and west of the International Date Line are the numerous small islands of Micronesia, including the Caroline Islands, the Marshall Islands and the Mariana Islands.

Big Sur Coast in Central California.

In the southwestern corner of the Pacific lie the islands of Melanesia, dominated by New Guinea. Other important island groups of Melanesia include the Bismarck Archipelago, Fiji, New Caledonia, the Solomon Islands and Vanuatu.

Islands in the Pacific Ocean are of four basic types: continental islands, high islands, coral reefs, and uplifted coral platforms. Continental islands lie outside the andesite line and include New Guinea, the islands of New Zealand, and the Philippines. Some of these islands are structurally associated with nearby continents. High islands are of volcanic origin, and many contain active volcanoes. Among these are Bougainville, Hawaii, and the Solomon Islands.

The third and fourth types of islands are both the result of coralline island building. Coral reefs are low-lying structures that have built up on basaltic lava flows under the ocean's surface. One of the most dramatic is the Great Barrier Reef off northeastern Australia. A second island type formed of coral is the uplifted coral platform, which is usually slightly larger than the low coral islands. Examples include Banaba (formerly Ocean Island) and Makatea in the Tuamotu group of French Polynesia.

History and economy[link]

Maris Pacifici by Ortelius (1589). One of the first printed maps to show the Pacific Ocean; see also Waldseemüller map (1507).^[9]

USS Lexington under air attack on 8 May 1942 during the Battle of the Coral Sea.

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 and then to Hawaii, New Zealand, and Easter Island.

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 world circumnavigation from 1519 to 1522. Magellan called the ocean Pacífico or "Pacific" because he encountered calm seas throughout his journey. Although Magellan himself died in the Philippines in 1521, Spanish navigator Juan Sebastian 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.

In 1564, Spanish explorers crossed the ocean from Mexico led by Miguel López de Legazpi who sailed to the Philippines and Mariana Islands. For the remainder of the 16th century, Spanish influence was paramount, with ships sailing from Mexico and Peru across the Pacific Ocean to the Philippines, via 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 also discovered the Pitcairn and Vanuatu archipelagos, and sailed the Torres Strait between Australia and New Guinea, named after navigator Luis 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. The 18th century marked the beginning of major exploration by the Russians in Alaska and the Aleutian Islands. The Spanish 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.^[10] The Spanish organized one of the earliest voyages of scientific exploration with the Malaspina Expedition of 1789-1794 that sailed vast areas of the Pacific, from Cape Horn to Alaska, Guam and the Philippines, New Zealand, Australia and the South Pacific.

The Bathyscaphe Trieste, before her record dive to the bottom of the Mariana Trench, 23 January 1960.

Growing imperialism during the 19th century resulted in the occupation of much of Oceania by other European powers, and later, the United States and Japan. 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 was the virtual master of the ocean. Since the end of World War II, many former colonies in the Pacific have become independent states.

The exploitation of the Pacific's mineral wealth is hampered by the ocean's great depths. In shallow waters of the continental shelves off the coasts of Australia and New Zealand, petroleum and natural gas are extracted, and pearls are harvested along the coasts of Australia, Japan, Papua New Guinea, Nicaragua, Panama, and the Philippines, although in sharply declining volume in some cases.

Fish are an important economic asset in the Pacific. The shoreline waters of the continents and the more temperate islands yield herring, salmon, sardines, snapper, swordfish, and tuna, as well as shellfish.

Environmental issues[link]

Marine debris on a Hawaiian coast

The quantity of small plastic fragments floating in the north-east Pacific Ocean has increased a hundred fold over the past 40 years (2012).^[11]

Marine pollution is a generic term for the harmful entry into the ocean of chemicals or particles. The biggest culprits are people who use the rivers for disposing of their waste.^[12] The rivers then empty into the Ocean, and with it the many chemicals used as fertilizers in agriculture. The excess of oxygen depleting chemicals in the water leads to hypoxia and the creation of a dead zone.^[13]

Marine debris, also known as marine litter, is a term used to describe human-created waste that has ended up floating in a lake, sea, ocean or waterway. Oceanic debris tends to accumulate at the centre of gyres and coastlines, frequently washing aground where it is known as beach litter.^[12]

In addition, the Pacific Ocean served as the crash site of satellites, including Mars 96, Fobos-Grunt and Upper Atmospheric Research Satellite.

Bordering countries and territories[link]

Sovereign nations[link]

¹ The status of the PRC vs. the ROC is disputed. For more information, see status of Taiwan.

Territories[link]

Major ports and harbors[link]

See also[link]

	Environment portal
	Ecology portal
	Geography portal
	Weather portal

References[link]

Further reading[link]

Based on public domain text from US Naval Oceanographer

External links[link]

Look up pacific ocean in Wiktionary, the free dictionary.

Wikimedia Commons has media related to: Pacific Ocean

• EPIC Pacific Ocean Data Collection Viewable on-line collection of observational data
• NOAA In-situ Ocean Data Viewer plot and download ocean observations
• NOAA PMEL Argo profiling floats Realtime Pacific Ocean data
• NOAA TAO El Niño data Realtime Pacific Ocean El Niño buoy data
• NOAA Ocean Surface Current Analyses – Realtime (OSCAR) Near-realtime Pacific Ocean Surface Currents derived from satellite altimeter and scatterometer data

Coordinates: 0°N 160°W / 0°N 160°W / 0; -160

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lez:Секин океан

The Earthquake in Chile (published in 1807), (German: ''Das Erdbeben in Chili'') is a novella written by Heinrich von Kleist (1777–1811).
The novella's central characters are two lovers, caught up in the chaos of the 1647 Santiago earthquake in Chile.

Synopsis[link]

The story begins with the lead character, Jeronimo Rugera, preparing to hang himself in prison in Santiago in 1647. Rugera had been a tutor at the house of Don Asteron, but Don Asteron dismissed him upon Asteron's discovery of an illicit relationship between his daughter and Jeronimo. Jeronimo and Josephe continued their relationship and were soon discovered by Josephe's brother. Don Asteron sends Josephe to a convent, where she and Jeronimo continue their relationship, until one day Josephe gave birth on the steps of the cathedral.

The city folk are excited by this story and Josephe was scheduled to be executed. As the procession marched towards the execution site, Jeronimo prepares to hang himself. At this moment, a strong earthquake destroys much of the city, freeing Jeronimo from prison. Despite his fears that Josephe had already died, he begins to search for her, and is later reunited with her and their son, Philipp.

On her way to her execution as the earthquake strikes, Josephe rescues her son from the convent, where she had entrusted him to an abbess. The abbess and most of the nuns are dead. Josephe had spent much of the day searching for Jeronimo and fearing him dead. They plan to travel to Concepción, Chile, where Josephe has family, and from there to Spain. ^[1]

The following morning, the couple is approached by Don Fernando who asks Josephe to breast feed his son, Juan, since his wife, Donna Elvira, has been injured in the earthquake. She complies, and Don Fernando invites the reunited family to join his own. They are greeted as friends, and exchange stories and rumours of the happenings in Santiago. Jeronimo and Josephe decide to go to Concepción and write to the Viceroy of Santiago to ask permission to stay in Chile.

That afternoon, a service is to be held at the lone surviving church in Santiago and the party, aside from Donna Elvira and her father Don Pedro, decides to attend. Donna Elvira appears to fear for Josephe's and Jeronimo's safety but Don Pedro feels that Donna Elvira's fears are misplaced. They attend the service.

The sermon compares the earthquake to God's destruction of Sodom and Gomorrah and speaks specifically of Josephe and Jeronimo's sin. Donna Constanza, Don Fernando's sister in law, recognizes the danger, but before the party can make their escape, someone calls out, identifying Josephe as the adulteress and accusing Don Fernando of being Jeronimo.

Josephe, who is holding Don Fernando's son Juan is grabbed by the crowd. The crowd assumes Juan is Josephe's baby. Don Fernando identifies himself and attempts to rescue Josephe. A naval officer, Don Alonzo, identifies Don Fernando but hesitates when a cobbler asks about Josephe. Josephe gives Juan and Phillip, who was being held by Jeronimo, to Don Fernando and tells him to leave and save the children, but he refuses and borrows Don Alonzo's sword. The crowd allows them to leave, and just as they think it's safe to enter the courtyard, a man claims that he is Jeronimo's father and clubs Jeronimo over the head. Donna Constanza, who had been walking with Jeronimo, runs to Don Alonzo, but is mistaken for Josephe and is also clubbed to death. Seeing this, Josephe gives herself up to the crowd and is clubbed by the cobbler, Master Pedrillo. Don Fernando defends the children with his sword but eventually his son, Juan, is torn from his grasp and bashed against a pillar.^[2]

The crowd disperses and Don Fernando is left with Philipp, whom he adopts as his own child with Donna Elvira. At the conclusion, Don Fernando compares Juan and Philipp and considers how he had acquired them, and remarks; "It almost seemed to him that he should be glad." ^[3]

Characters[link]

• Jeronimo Rugera - A Spaniard, the lover of Josephe
• Josephe Asteron - Daughter of the richest nobleman in the city, the lover of Jeronimo
• Philipp - The son of Jeronimo and Josephe
• Don Fernando Ormez - An acquaintance of Josephe, husband of Donna Elvira
• Donna Elvira - Don Fernando's wife
• Juan - Donna Elvira and Don Fernando's son
• Don Pedro - Donna Elvira's Father
• Donna Isabel - A relation of Don Fernando
• Donna Constanza - Sister of Donna Elvira
• Master Pedrillo - A cobbler
• Don Alonzo - An acquaintance of Don Fernando and Josephe, a naval officer

References[link]

1. ^ http://www.www.litencyc.com/php/sworks.php?rec=true&UID=13114
2. ^ http://findarticles.com/p/articles/mi_qa3692/is_200205/ai_n9037867/
3. ^ *1978, UK, Penguin books ISBN 0-14-044359-2, Pub date 29 June 1978, paperback (D. Luke translator & N. Reeves translator)

External links[link]

• German Text
• read in German librivox.org (No. 8)