View source for Pacific Ocean

{{Short description|Largest ocean}}
{{Redirect-several|dab=off|Pacific Northwest|North Pacific (disambiguation)|Pacific Southwest|South Pacific (disambiguation)|Pacific (disambiguation)|Western Pacific}}
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{{Use American English|date=May 2019}}
{{Use dmy dates|date=November 2019}}

{{Infobox body of water
| name               = Pacific Ocean
| image              = Pacific Ocean - en.png
| alt                = Map of the Pacific Ocean
| coords             = {{Coord|0|N|160|W|region:XP_type:waterbody_dim:20000000|display=inline,title}}
| area               = {{convert|165250000|km2|abbr=on}}
| depth              = {{convert|4280|m|abbr=on}}
| max-depth          = {{convert|10911|m|abbr=on}}
| volume             = {{circa}} {{convert|710000000|km3|abbr=on}}
| shore              = 
| islands            = [[List of islands in the Pacific Ocean|Pacific Islands]]
| trenches           = 
| cities             = [[List of ports and harbors of the Pacific Ocean|List]]
| mapframe-zoom      = 0
}}

{{Five oceans}}

The '''Pacific Ocean''' is the largest and deepest of [[Earth]]'s five [[borders of the oceans|oceanic divisions]]. It stretches from the [[Arctic Ocean]] in the north to the [[Southern Ocean]], or, depending on the definition, to [[Antarctica]] in the south, and is bounded by the continents of [[Asia]] and [[Australia (continent)|Australia]] in the west and the [[Americas]] in the east.

At {{convert|165250000|km2|sp=us|abbr=off}} in area (as defined with a southern Antarctic border), the Pacific Ocean is the largest division of the [[Ocean#World Ocean|World Ocean]] and the [[hydrosphere]] and covers approximately 46% of Earth's water surface and about 32% of the planet's total surface area, larger than its entire land area combined ({{convert|148940000 |sqkm|sp=us|disp=or}}).<ref name="ebc">"[https://www.britannica.com/place/Pacific-Ocean Pacific Ocean]". ''[[Encyclopædia Britannica|Britannica Concise]].'' 2008: Encyclopædia Britannica, Inc.</ref> The centers of both the [[land and water hemispheres|water hemisphere]] and the [[Western Hemisphere]], as well as the [[Pole of inaccessibility#Oceanic pole of inaccessibility|oceanic pole of inaccessibility]], are in the Pacific Ocean. Ocean circulation (caused by the [[Coriolis effect]]) subdivides it<ref>{{cite web|url=https://oceanservice.noaa.gov/education/tutorial_currents/04currents1.html|title=The Coriolis Effect|publisher=National Oceanic and Atmospheric Administration|accessdate=8 April 2022}}</ref> into two largely independent volumes of water that meet at the [[Equator]], the '''North Pacific Ocean''' and the '''South Pacific Ocean''' (or more loosely the [[South Seas]]). The Pacific Ocean can also be informally divided by the [[International Date Line]] into the '''East Pacific''' and the '''West Pacific''', which allows it to be further divided into four quadrants, namely the '''Northeast Pacific''' off the coasts of [[North America]], the '''Southeast Pacific''' off [[South America]], the '''Northwest Pacific''' off [[Far East]]ern/[[Pacific Asia|Pacific]] [[Asia]], and the '''Southwest Pacific''' around [[Oceania]].

The Pacific Ocean's mean depth is {{convert|4000|m|ft fathom|sp=us|abbr=off}}.<ref>{{Cite web|url=https://oceanexplorer.noaa.gov/facts/pacific-size.html|title=How big is the Pacific Ocean?|website=US Department of Commerce, National Oceanic and Atmospheric Administration|language=EN-US|access-date=18 October 2018}}</ref> The [[Challenger Deep]] in the [[Mariana Trench]], located in the northwestern Pacific, is the deepest known point in the world, reaching a depth of {{cvt|10928|m|ft fathom}}.<ref>{{Cite web|url=https://fivedeeps.com/wp-content/uploads/2019/05/FDE-Challenger-Release-FINAL-5132019.pdf|title=Deepest Submarine Dive in History, Five Deeps Expedition Conquers Challenger Deep}}</ref> The Pacific also contains the deepest point in the [[Southern Hemisphere]], the [[Horizon Deep]] in the [[Tonga Trench]], at {{cvt|10823|m|ft fathom}}.<ref>{{Cite web|url=https://fivedeeps.com/wp-content/uploads/2019/06/2019-06-11-FDE-Press-Release-Tonga.pdf|title=CONFIRMED: Horizon Deep Second Deepest Point on the Planet}}</ref> The third deepest point on Earth, the [[Sirena Deep]], is also located in the Mariana Trench.

The Pacific has many major [[marginal sea]]s, including (listed clockwise from the west) the [[Philippine Sea]], [[South China Sea]], [[East China Sea]], [[Sea of Japan]], [[Sea of Okhotsk]], [[Bering Sea]], [[Gulf of Alaska]], [[Gulf of California]], [[Tasman Sea]], and [[Coral Sea]].

== Etymology ==
In 1513, during the [[Age of Discovery]], [[History of Spain#early modern Spain|Spanish]] explorer [[Vasco Núñez de Balboa]] crossed the [[Isthmus of Panama]] and sighted the great "Southern Sea", which he named {{lang|es|Mar del Sur}} (in Spanish). Afterwards, the ocean's current name was coined by Portuguese explorer [[Ferdinand Magellan]] during the Spanish [[circumnavigation]] of the world in 1520, as he encountered favorable winds upon reaching the ocean. He called it {{lang|pt|Mar Pacífico}}, which in Portuguese and Spanish means 'peaceful sea'.<ref>{{Catholic Encyclopedia |wstitle=Ferdinand Magellan |inline=1 }}</ref><ref>{{cite web |first=Evan |last=Andrews |title=10 Surprising Facts About Magellan's Circumnavigation of the Globe |url=https://www.history.com/news/10-surprising-facts-about-magellans-circumnavigation-of-the-globe |date=17 October 2023 |website=history.com |publisher=[[A&E Networks]] |access-date=27 September 2024}}</ref>

== History ==
=== Prehistory ===
Across the continents of [[Asia]], [[Australia (continent)|Australia]] and the [[Americas]], more than 25,000 islands, large and small, rise above the surface of the Pacific Ocean. Multiple islands are the shells of former active [[volcano]]es that have lain dormant for thousands of years (see also [[Ring of Fire]]). Close to the [[equator]], without vast areas of blue ocean, are a dot of [[atoll]]s that have over intervals of time been formed by [[seamounts]] as a result of tiny [[coral island]]s strung in a ring within surroundings of a central [[lagoon]].

=== Early migrations ===
{{Main|Peopling of Southeast Asia|Austronesian peoples}}

[[File:Fijian double canoe, model, Otago Museum, 2016-01-29.jpg|thumb|Model of a [[Fiji]]an [[drua]], an example of an [[Austronesian peoples|Austronesian vessel]] with a double-canoe ([[catamaran]]) hull and a [[crab claw sail]]]]
Important human migrations occurred in the Pacific in prehistoric times. Modern humans first reached the western Pacific in the [[Paleolithic]], at around 60,000 to 70,000 years ago. Originating from a southern coastal human migration out of Africa, they reached [[East Asia]], [[Mainland Southeast Asia]], the Philippines, [[New Guinea]], and then Australia by making the sea crossing of at least {{convert|80|km}} between [[Sundaland]] and [[Australia (continent)|Sahul]]. It is not known with any certainty what level of maritime technology was used by these groups{{snd}}the presumption is that they used large bamboo rafts which may have been equipped with some sort of sail. The reduction in favourable winds for a crossing to Sahul after 80,000 B.P. fits with the dating of the settlement of Australia, with no later migrations in the prehistoric period. The seafaring abilities of pre-Austronesian residents of Island South-east Asia are confirmed by the settlement of [[Buka, Papua New Guinea|Buka]] by 32,000 B.P. and [[Manus Island|Manus]] by 25,000 B.P. Journeys of {{convert|180|km}} and {{convert|230|km}} are involved, respectively.<ref>{{cite book |last1=O'Connor |first1=Sue |last2=Hiscock |first2=Peter |editor1-last=Cochrane |editor1-first=Ethan E |editor2-last=Hunt |editor2-first=Terry L. |title=The Oxford handbook of prehistoric Oceania |date=2018 |location=New York |publisher=Oxford University Press |isbn=978-0199925070 |chapter=The Peopling of Sahul and Near Oceania}}</ref>

The descendants of these migrations today are the [[Negritos]], [[Melanesians]], and [[Indigenous Australians]]. Their populations in [[maritime Southeast Asia]], coastal [[New Guinea]], and [[Island Melanesia]] later intermarried with the incoming [[Austronesian peoples|Austronesian]] settlers from [[Taiwan]] and the northern [[Philippines]], but also earlier groups associated with [[Austroasiatic languages|Austroasiatic-speakers]], resulting in the modern peoples of Island Southeast Asia and Oceania.<ref name="Jett2017">{{cite book |last1=Jett |first1=Stephen C. |title=Ancient Ocean Crossings: Reconsidering the Case for Contacts with the Pre-Columbian Americas |date=2017 |publisher=University of Alabama Press |isbn=978-0817319397 |pages=168–171 |url=https://books.google.com/books?id=EgOUDgAAQBAJ |access-date=4 June 2020 |archive-date=26 July 2020 |archive-url=https://web.archive.org/web/20200726125617/https://books.google.com/books?id=EgOUDgAAQBAJ |url-status=live }}</ref><ref name="Waruno2017">{{cite book|author =Mahdi, Waruno|editor =Acri, Andrea|editor2 =Blench, Roger|editor3 =Landmann, Alexandra|title =Spirits and Ships: Cultural Transfers in Early Monsoon Asia|chapter =Pre-Austronesian Origins of Seafaring in Insular Southeast Asia|publisher =ISEAS – Yusof Ishak Institute|year =2017|pages =325–440|isbn =978-9814762755|chapter-url =https://books.google.com/books?id=uJsnDwAAQBAJ|access-date =4 June 2020|archive-date =26 July 2020|archive-url =https://web.archive.org/web/20200726134025/https://books.google.com/books?id=uJsnDwAAQBAJ|url-status =live}}</ref>

[[File:Chronological dispersal of Austronesian people across the Pacific.svg|thumb|upright=2|Map showing the [[Austronesian peoples#Migration from Taiwan|migration]] of the [[Austronesian peoples]]]]
A later seaborne migration is the [[Neolithic]] [[Austronesian expansion]] of the [[Austronesian peoples]]. Austronesians originated from the island of [[Taiwanese aborigines|Taiwan]] {{c.|3000}}–1500 BCE. They are associated with distinctive maritime sailing technologies (notably [[outrigger boat]]s, [[catamaran]]s, [[lashed-lug]] boats, and the [[crab claw sail]]){{snd}}it is likely that the progressive development of these technologies were related to the later steps of settlement into Near and Remote Oceania. Starting at around 2200 BCE, Austronesians sailed southwards to settle the [[Philippines]]. They crossed the western Pacific from the [[Bismarck Archipelago]] to reach the [[Marianas Islands]] by 1500 BCE,<ref>{{cite journal |last1=Winter |first1=Olaf |last2=Clark |first2=Geoffrey |last3=Anderson |first3=Atholl |last4=Lindahl |first4=Anders |title=Austronesian sailing to the northern Marianas, a comment on Hung et al. (2011) |journal=Antiquity |date=September 2012 |volume=86 |issue=333 |pages=898–910 |doi=10.1017/S0003598X00047992 }}</ref> as well as [[Palau]] and [[Yap]] by 1000 BCE. They were the first humans to reach [[Remote Oceania]], and the first to cross vast distances of open water. They also continued spreading southwards and settling the rest of [[Maritime Southeast Asia]], reaching [[Indonesia]] and [[Malaysia]] by 1500 BCE, and further west to [[Madagascar]] and the [[Comoros]] in the [[Indian Ocean]] by around 500 CE.<ref>{{Cite journal|last1=Heiske|first1=Margit|last2=Alva|first2=Omar|last3=Pereda-Loth|first3=Veronica|last4=Van Schalkwyk|first4=Matthew|last5=Radimilahy|first5=Chantal|last6=Letellier|first6=Thierry|last7=Rakotarisoa|first7=Jean-Aimé|last8=Pierron|first8=Denis|date=22 January 2021|title=Genetic evidence and historical theories of the Asian and African origins of the present Malagasy population|journal=Human Molecular Genetics|volume=30|issue=R1|pages=R72–R78|doi=10.1093/hmg/ddab018|pmid=33481023 |doi-access=free}}</ref><ref name="Gray-et-al2009">{{cite journal | vauthors = Gray RD, Drummond AJ, Greenhill SJ | title = Language phylogenies reveal expansion pulses and pauses in Pacific settlement | journal = Science | volume = 323 | issue = 5913 | pages = 479–483 | date = January 2009 | pmid = 19164742 | doi = 10.1126/science.1166858 | bibcode = 2009Sci...323..479G }}</ref><ref name="Pawley2002">{{cite book | vauthors = Pawley A |chapter=The Austronesian dispersal: languages, technologies and people |editor1-first=Peter S. |editor1-last=Bellwood |editor2-first=Colin |editor2-last=Renfrew |title=Examining the farming/language dispersal hypothesis |publisher=McDonald Institute for Archaeological Research, University of Cambridge |year=2002 |isbn=978-1902937205 |pages=251–273 }}</ref> More recently, it is suggested that Austronesians expanded already earlier, arriving in the Philippines already in 7000 BCE. Additional earlier migrations into Insular Southeast Asia, associated with Austroasiatic-speakers from Mainland Southeast Asia, are estimated to have taken place already in 15000 BCE.<ref>{{Cite journal |last=Larena |first=Maximilian |date= 22 March 2021|title=Multiple migrations to the Philippines during the last 50,000 years |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=118 |issue=13 |article-number=e2026132118 |doi=10.1073/pnas.2026132118 |pmid=33753512 |pmc=8020671 |bibcode=2021PNAS..11826132L |doi-access=free }}</ref>

At around 1300 to 1200 BCE, a branch of the Austronesian migrations known as the [[Lapita culture]] reached the [[Bismarck Archipelago]], the [[Solomon Islands]], [[Vanuatu]], [[Fiji]], and [[New Caledonia]]. From there, they settled [[Tonga]] and [[Samoa]] by 900 to 800 BCE. Some also back-migrated northwards in 200 BCE to settle the islands of eastern [[Micronesia]] (including the [[Caroline Islands|Carolines]], the [[Marshall Islands]], and [[Kiribati]]), mixing with earlier Austronesian migrations in the region. This remained the furthest extent of the Austronesian expansion into [[Polynesia]] until around 700 CE when there was another surge of island exploration. They reached the [[Cook Islands]], [[Tahiti]], and the [[Marquesas]] by 700 CE; [[Hawaii|Hawai{{okina}}i]] by 900 CE; [[Rapa Nui]] by 1000 CE; and finally New Zealand by 1200 CE.<ref name="Gray-et-al2009"/><ref name="Stanley2004">{{cite book|last=Stanley|first=David|title=South Pacific|url=https://archive.org/details/bub_gb_EDGapfBX-CAC|date=2004|publisher=Avalon Travel |isbn=978-1-56691-411-6|page=[https://archive.org/details/bub_gb_EDGapfBX-CAC/page/n38 19]}}</ref><ref name="gibbons">{{cite web |last1=Gibbons |first1=Ann |title='Game-changing' study suggests first Polynesians voyaged all the way from East Asia |url=https://www.science.org/content/article/game-changing-study-suggests-first-polynesians-voyaged-all-way-east-asia |website=Science |access-date=23 March 2019 |archive-date=13 April 2019 |archive-url=https://web.archive.org/web/20190413063912/https://www.sciencemag.org/news/2016/10/game-changing-study-suggests-first-polynesians-voyaged-all-way-east-asia |url-status=live }}</ref> Austronesians may have also reached as far as the [[Americas]], although evidence for this remains inconclusive.<ref>Van Tilburg, Jo Anne. 1994. ''Easter Island: Archaeology, Ecology and Culture.'' Washington D.C.: Smithsonian Institution Press</ref><ref>Langdon, Robert. The Bamboo Raft as a Key to the Introduction of the Sweet Potato in Prehistoric Polynesia, ''The Journal of Pacific History'', Vol. 36, No. 1, 2001</ref>

=== European exploration ===
{{Main|Exploration of the Pacific}}
[[File:Waldseemuller map 2.jpg|thumb|upright=1.1|''Universalis Cosmographia'', also known as the [[Waldseemüller map]], dated 1507, was the first map to show the [[Americas]] separating two distinct oceans. South America was generally considered the [[New World]] and shows the name "America" for the first time, after [[Amerigo Vespucci]]]]
The first contact of European navigators with the western edge of the Pacific Ocean was made by the Portuguese expeditions of [[António de Abreu]] and [[Francisco Serrão]], via the [[Lesser Sunda Islands]], to the [[Maluku Islands]], in 1512,<ref>{{cite book|last=Hannard|first=Willard A.|title=Indonesian Banda: Colonialism and its Aftermath in the Nutmeg Islands|publisher=Yayasan Warisan dan Budaya Banda Naira|year=1991|location=[[Bandanaira]]|page=7}}</ref><ref>{{cite book|last=Milton|first=Giles|author-link=Giles Milton|title=Nathaniel's Nutmeg|publisher=Sceptre|date=1999|location=London|pages=5, 7|isbn= 978-0-340-69676-7}}</ref> and with [[Jorge Álvares]]'s expedition to southern China in 1513,<ref name="Porter, Jonathan 1996">Porter, Jonathan. (1996). ''Macau, the Imaginary City: Culture and Society, 1557 to the Present''. Westview Press. {{ISBN|0-8133-3749-6}}</ref> both ordered by [[Afonso de Albuquerque]] from [[Portuguese Malacca|Malacca]].

The eastern side of the ocean was encountered by Spanish explorer [[Vasco Núñez de Balboa]] in 1513 after his expedition crossed the [[Isthmus of Panama]] and reached a new ocean.<ref name="Ober">{{cite book|last=Ober|first=Frederick Albion|title=Vasco Nuñez de Balboa|url=https://books.google.com/books?id=98zUIbdvAYgC&pg=PT129|publisher=Library of Alexandria|isbn=978-1-4655-7034-5|page=129|year=2010}}</ref> He named it ''Mar del Sur'' ("Sea of the South" or [[South Seas|"South Sea"]]) because the ocean was to the south of the coast of the isthmus where he first observed the Pacific.

In [[1520]], navigator [[Ferdinand Magellan]] and his crew were the first to cross the Pacific in recorded history. They were part of a [[Magellan–Elcano circumnavigation|Spanish expedition]] to the [[Spice Islands]] that would eventually result in the first world [[circumnavigation]]. Magellan called the ocean ''Pacífico'' (or "Pacific" meaning, "peaceful") because, after sailing through the stormy seas off [[Cape Horn]], the expedition found calm waters. The ocean was often called the '''Sea of Magellan''' in his honor until the eighteenth century.<ref>Camino, Mercedes Maroto. ''Producing the Pacific: Maps and Narratives of Spanish Exploration (1567–1606)'', p. 76. 2005.</ref> Magellan stopped at one uninhabited Pacific island before stopping at [[Guam]] in March 1521.<ref>{{cite web |last1=Madrid |first1=Carlos |title=Ferdinand Magellan - Guampedia |url=https://www.guampedia.com/ferdinand-magellan/ |website=guampedia.com |date=30 September 2009}}</ref>
Magellan himself died in the [[Philippines]] in 1521. Spanish navigator [[Juan Sebastián Elcano]] led the remains of the expedition back to Spain across the [[Indian Ocean]] and round the [[Cape of Good Hope]], completing the first world [[circumnavigation]] in 1522.<ref name=oceanario>[https://archive.today/20130616003402/http://www.oceanario.pt/cms/1316/ "Life in the sea: Pacific Ocean"], Oceanário de Lisboa. Retrieved 9 June 2013.</ref> Sailing around and east of the Moluccas, between 1525 and 1527, Portuguese expeditions encountered the [[Caroline Islands]],<ref>{{cite book|last=Galvano|first=Antonio|title=The Discoveries of the World from Their First Original Unto the Year of Our Lord 1555, issued by the Hakluyt Society|publisher=Kessinger Publishing|orig-year=1563|date=2004|url=https://books.google.com/books?id=XivHTiZoMycC&pg=1|isbn=978-0-7661-9022-1|ref=Galvano 1563|author-link=António Galvão|page=168}}{{Dead link|date=October 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> the [[Aru Islands Regency|Aru Islands]],<ref>{{cite book |last=Kratoska |first=Paul H. |title=South East Asia, Colonial History: Imperialism before 1800, Volume 1 de South East Asia, Colonial History |publisher=Taylor & Francis |year=2001 |pages=52–56}}[https://books.google.com/books?id=Z9U-FUPS3DkC]</ref> 
and [[Papua New Guinea]].<ref name=Whiteway>{{cite book|last=Whiteway|first=Richard Stephen|title=The rise of Portuguese power in India, 1497–1550|publisher=A. Constable|date=1899|location=Westminster|url=https://archive.org/details/riseportuguesep00whitgoog|page=[https://archive.org/details/riseportuguesep00whitgoog/page/n353 333]}}</ref> In 1542–43 the Portuguese also reached Japan.<ref>Steven Thomas, {{cite web|url=http://balagan.info/portuguese-in-japan|title=Portuguese in Japan|publisher=Steven's Balagan|access-date=22 May 2015|date=25 April 2006}}</ref>

In 1564, five Spanish ships carrying 379 soldiers crossed the Pacific from [[Mexico]] led by [[Miguel López de Legazpi]], and colonized the [[Philippines]] and [[Mariana Islands]].<ref name="HendersonDelpar2000">{{cite book|last1=Henderson|first1=James D.|last2=Delpar|first2=Helen|last3=Brungardt|first3=Maurice Philip|author4=Weldon, Richard N.|title=A Reference Guide to Latin American History|url=https://archive.org/details/referenceguideto00hend|url-access=registration|year=2000|publisher=M.E. Sharpe|isbn=978-1-56324-744-6|page=[https://archive.org/details/referenceguideto00hend/page/28 28]}}</ref> 
For the remainder of the 16th century, Spain maintained military and mercantile control, with ships sailing from Mexico and [[Peru]] across the Pacific Ocean to the Philippines via [[Guam]], and establishing the [[Spanish East Indies]]. The [[Manila galleon]]s operated for two and a half centuries, linking [[Manila]] and [[Acapulco]], in one of the longest [[Waterway|trade routes]] in history. Spanish expeditions also arrived at [[Tuvalu]], the [[Marquesas Islands|Marquesas]], the [[Cook Islands]], the [[Solomon Islands]], [[Vanuatu]], the [[Marshall Islands|Marshalls]] and the [[Admiralty Islands]] in the South Pacific.<ref name="Fernandez-Armesto 2006 305–307">{{cite book|last=Fernandez-Armesto|first=Felipe|title=Pathfinders: A Global History of Exploration|date=2006|publisher=W.W. Norton & Company|isbn=978-0-393-06259-5|pages=[https://archive.org/details/pathfindersgloba00fern/page/305 305–307]|url=https://archive.org/details/pathfindersgloba00fern/page/305}}</ref>

Later, in the quest for [[Terra Australis]] ("the [great] Southern Land"), Spanish explorations in the 17th century, such as the expedition led by the Portuguese navigator [[Pedro Fernandes de Queirós]], arrived at the [[Pitcairn Islands|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 exploration and trade; [[Willem Janszoon]], made the first completely documented European landing in Australia (1606), in [[Cape York Peninsula]],<ref>J.P. Sigmond and L.H. Zuiderbaan (1979) ''Dutch Discoveries of Australia''.Rigby Ltd, Australia. pp. 19–30 {{ISBN|0-7270-0800-5}}</ref> and [[Abel Tasman|Abel Janszoon Tasman]] circumnavigated and landed on parts of the Australian continental coast and arrived at [[Tasmania]] and New Zealand in 1642.<ref>{{cite book|title=Primary Australian History: Book F [B6] Ages 10–11|url=https://books.google.com/books?id=_i98Pu5dDhkC&pg=PA6|date=2008|publisher=R.I.C. Publications|isbn=978-1-74126-688-7|page=6}}</ref>

In the 16th and 17th centuries, Spain considered the Pacific Ocean a ''[[mare clausum]]''{{snd}}a sea closed to other naval powers. As the only known entrance from the Atlantic, the [[Strait of Magellan]] was at times patrolled by fleets sent to prevent the entrance of non-Spanish ships. On the western side of the Pacific Ocean the Dutch threatened the [[Philippines|Spanish Philippines]].<ref name=lytle>{{Citation|last=Lytle Schurz|first=William|title=The Spanish Lake|journal=[[The Hispanic American Historical Review]] |volume=5|issue=2|date=1922|pages=181–194|jstor=2506024|doi=10.2307/2506024}}</ref>

The 18th century marked the beginning of major exploration by Russians in [[Alaska]] and the [[Aleutian Islands]], such as the [[First Kamchatka expedition]] and the [[Great Northern Expedition]], led by the Danish-born Russian navy officer [[Vitus Bering]]. Spain also sent [[Spanish expeditions to the Pacific Northwest|expeditions to the Pacific Northwest]], reaching [[Vancouver Island]] in southern Canada, and Alaska. 
The French explored and colonized [[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.<ref name="Williams2004">{{cite book|last=Williams|first=Glyndwr|title=Captain Cook: Explorations And Reassessments|url=https://books.google.com/books?id=VqDHGru-zcIC&pg=PA143|date=2004|publisher=Boydell Press|isbn=978-1-84383-100-6|page=143}}</ref> 

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.<ref name="Fernandez-Armesto 2006 305–307" />

<gallery mode="packed">
File:Carta universal en que se contiene todo lo que del mundo se ha descubierto fasta agora hizola Diego Ribero cosmographo de su magestad, ano de 1529, en Sevilla.jpg|Made in 1529, the [[Diogo Ribeiro (cartographer)|Diogo Ribeiro]] map was the first to show the Pacific at about its proper size
File:A compleat chart of the coast of Asia and America with the great South Sea - R.W. Seale del. et sculp. NYPL465242.tiff|Map of the Pacific Ocean during European Exploration, circa 1754.
File:Ortelius - Maris Pacifici 1589.jpg|[[Maris Pacifici]] by [[Abraham Ortelius|Ortelius]] (1589). One of the first printed maps to show the Pacific Ocean<ref>{{cite web|url=https://www.loc.gov/item/prn-01-093/|title=Library Acquires Copy of 1507 Waldseemüller World Map – News Releases (Library of Congress)|publisher=Loc.gov|access-date=April 20, 2013}}</ref>
File:A generall chart of the South Sea ... NYPL481132.tiff|Map of the Pacific Ocean during European Exploration, circa 1702–1707
</gallery>

=== New Imperialism ===
{{See also|New Imperialism|Pacific Century}}
[[File:Trieste (23 Jan 1960).jpeg|thumb|The bathyscaphe ''[[Trieste (bathyscaphe)|Trieste]]'' before her record dive to the bottom of the [[Mariana Trench]], 23 January 1960]]
[[File:TahitiDupetitThouars.jpg|thumb|[[Abel Aubert du Petit-Thouars]] taking over [[Tahiti]] on 9 September 1842]]
Growing [[imperialism]] during the 19th century resulted in the occupation of much of Oceania by European powers, and later [[Japanese colonial empire|by Japan]] and the [[Foreign interventions by the United States|by United States]]. Significant contributions to [[oceanographic]] knowledge were made by the voyages of [[HMS Beagle|HMS ''Beagle'']] in the 1830s, with [[Charles Darwin]] aboard;<ref>{{Cite news|url=https://www.scientificamerican.com/article/charles-darwins-travel-beagle/|title=Charles Darwin's Travels on the HMS Beagle|last=Marty|first=Christoph|work=Scientific American|access-date=23 March 2018|language=en}}</ref> [[HMS Challenger (1858)|HMS ''Challenger'']] during the 1870s;<ref>{{Cite web|url=http://www.interactiveoceans.washington.edu/story/HMS_Challenger|title=The Voyage of HMS Challenger|website=interactiveoceans.washington.edu|access-date=23 March 2018}}</ref> the [[USS Tuscarora (1861)|USS ''Tuscarora'']] (1873–76);<ref>{{Cite book|url=https://books.google.com/books?id=VP9BAAAAYAAJ&q=dab|title=A Synopsis of the Cruise of the U.S.S. "Tuscarora": From the Date of Her Commission to Her Arrival in San Francisco, Cal. Sept. 2d, 1874|date=1874|publisher=Cosmopolitan printing Company|language=en}}</ref> and the German ''Gazelle'' (1874–76).<ref>{{Cite journal|url=https://books.google.com/books?id=nE0pAAAAYAAJ&pg=PA101|title=A Physical, Historical, Political, & Descriptive Geography|journal=Nature|volume=22|issue=553|page=95|last=Johnston|first=Keith|date=1881|language=en|bibcode=1880Natur..22Q..95.|doi=10.1038/022095a0 |doi-access=free}}</ref>

In Oceania, France obtained a leading position as imperial power after making [[Tahiti]] and [[New Caledonia]] protectorates in 1842 and 1853, respectively.<ref name=Asiapacific>Bernard Eccleston, Michael Dawson. 1998. ''The Asia-Pacific Profile''. Routledge. p. 250.</ref> 
After navy visits to [[Easter Island]] in 1875 and 1887, Chilean navy officer [[Policarpo Toro]] negotiated the incorporation of the island into [[Chile]] with native [[Rapanui]] in [[1888 in Chile|1888]]. By occupying Easter Island, Chile joined the imperial nations.<ref name="sater">William Sater, ''Chile and the United States: Empires in Conflict'', 1990 by the University of Georgia Press, {{ISBN|0-8203-1249-5}}</ref>{{rp|page=53}} By 1900 nearly all Pacific islands were in control of Britain, France, United States, Germany, Japan, and Chile.<ref name=Asiapacific />

In 1898 ([[Spanish–American War]]), the United States gained control of [[Guam]] and the Philippines from Spain.<ref name="TewariAlvarez2008">{{cite book|last1=Tewari|first1=Nita|last2=Alvarez|first2=Alvin N.|title=Asian American Psychology: Current Perspectives|url=https://books.google.com/books?id=m8qgAi0LVj8C&pg=PA161|year=2008|publisher=CRC Press|isbn=978-1-84169-749-9|page=161}}</ref> 

===20th century===
{{expand section|date=March 2026}}
Prior to World War I United States attempted to purchase or at least establish a naval base in [[Galápagos Islands]]. Ecuador's staunch resistance to a US purchase or bases in the islands can be credited to Chilean diplomacy, which in turn was informally backed on this issue by [[United Kingdom of Great Britain and Ireland|Great Britain]] and [[German Empire|Germany]].<ref name="Fischer2008">{{cite journal |last1=Fischer |first1=Ferenc |title=La expansión (1885–1918) del modelo militar alemán y su pervivencia (1919–1933) en América Latina |journal=Revista del CESLA |date=21 April 2008 |volume=11 |pages=135–160 |url=https://www.revistadelcesla.com/index.php/revistadelcesla/article/view/196/193 |access-date=25 February 2021 |trans-title=The expansion (1885–1918) of the German military model and its survival (1919–1933) in Latin America |publisher=[[University of Warsaw]] |language=es}}</ref> 

The end of World War I strenghtened Japan and the United States in the Pacific, Japan in East Asia and United States mostly so in Latin America. Pacific rim countries like Colombia, Ecuador and Peru started to treat the United States as a hegemon, often seeking its mediation in international disputes.{{sfn|Mares|2001|p=68}} Chile on the other hand attempted to resist United States influence.{{sfn|Mares|2001|p=69}} 

The [[Washington Naval Treaty]] of 1921 is associated with various geopolitical effects in the Pacific Ocean, including the end of the [[Anglo-Japanese Alliance]]. Although it was not part of the Washington Treaty in any way, the American delegates had made it clear that they would not agree to the treaty unless the British ended their alliance with the Japanese.{{Sfn | Howarth | 1983 | p = 167}} The [[1921 Imperial Conference]] earlier in the year had already decided not to renew the Alliance.<ref>{{Citation|last=Nish |first=Ian H. |title=Alliance in Decline: A Study in Anglo-Japanese Relations 1908–23 |location=London |publisher=The Athlone Press |date=1972 |page=334 |isbn=0-485-13133-1 }}</ref> The regrouping the Royal Navy in 1921 also meant that it left the South Pacific that year.<ref name=Sater91>{{Cite book |title=Chile and the United States: Empires in Conflict |last=Sater |first=William F. |publisher=The University of Geargia Press |year=1990 |location=Athens and London |pages=91}}</ref> This weakened the position of Britain's old-time ally [[Chile]] and increased the influence of the United States in the Americas. Indirectly, the withdrawal emboldened Peruvian and Bolivian claims against Chile as these two states were often supported diplomatically by the United States.<ref name=Sater91/>{{sfn|Mares|2001|p=65}}

Japan occupied many Pacific islands during the [[Pacific War]] (1941–1945); however, by the end of that war, Japan was defeated and the [[United States Navy|U.S. Pacific Fleet]] was the virtual master of the ocean. The Japanese-ruled [[Northern Mariana Islands]] came under the control of the United States.<ref>''The Covenant to Establish a Commonwealth of the Northern Mariana Islands in Political Union With the United States of America'', {{USStatute|94|241|90|263|1976|03|24}}</ref> 

Since the end of World War II, many former colonies in the Pacific have become independent [[Sovereign state|states]] (→ [[Decolonisation of Asia]]).

== Geography ==
[[File:Iss007e10807.jpg|thumb|upright=1.1|Sunset over the Pacific Ocean as seen from the [[International Space Station]]. Tops of [[Cumulonimbus cloud|thunderclouds]] are also visible.]]
[[File:Pacific Basin Island Geography.jpg|thumb|upright=1.1|The island geography of the Pacific Ocean Basin]]
[[File:Pacific Culture Areas.png|thumb|upright=1.35|The three major cultural areas of the [[List of islands in the Pacific Ocean|Pacific Ocean islands]]: [[Micronesia]], [[Melanesia]] and [[Polynesia]]]]
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.<ref name=ebc /> The Pacific Ocean encompasses approximately one-third of the Earth's surface, having an area of {{convert|165250000|km2|abbr=on}}<ref name="ebc" />{{snd}}larger than Earth's entire landmass combined, {{convert|150000000|km2|abbr=on}}.<ref>[http://hypertextbook.com/facts/2001/DanielChen.shtml "Area of Earth's Land Surface"], ''The Physics Factbook''. Retrieved 9 June 2013.</ref>

Extending approximately {{convert|8400|nmi}} from the [[Bering Sea]] in the [[Arctic]] to the northern extent of the circumpolar [[Southern Ocean]] at [[60th parallel south|60°S]] (older definitions extend it to [[Antarctica]]'s [[Ross Sea]]), the Pacific reaches its greatest east–west width at about [[5th parallel north|5°N latitude]], where it stretches approximately {{convert|10700|NM}} from Indonesia to the coast of [[Colombia]]{{snd}}halfway around the world, and more than five times the diameter of the Moon.<ref name="Nuttall2005">{{cite book|last=Nuttall|first=Mark|title=Encyclopedia of the Arctic: A–F|url=https://books.google.com/books?id=LcucDSk4w3YC&pg=PA1461|date=2005|publisher=Routledge|isbn=978-1-57958-436-8|page=1461}}</ref> Its geographic center is in eastern [[Kiribati]] south of [[Kiritimati]], just west from [[Starbuck Island]] at {{Coord|4.97|S|158.75|W|format=dms|type:landmark_region:FR_scale:10000|display=inline}}.<ref>{{cite web | title=International Journal of Oceans and Oceanography, Volume 15 Number 1, 2021, Determining the Areas and Geographical Centers of Pacific Ocean and its Northern and Southern Halves, pp 25–31, Arjun Tan| website=Research India Publications| url=https://www.ripublication.com/Volume/ijoov15n1.htm | archive-url=https://web.archive.org/web/20210804032647/https://ripublication.com/Volume/ijoov15n1.htm | url-status=usurped | archive-date=4 August 2021 | ref={{sfnref}} | access-date=18 July 2022}}</ref> The lowest known point on Earth{{snd}}the [[Mariana Trench]]{{snd}}lies {{convert|10911|m|fathom ft|abbr=on|lk=out}} below sea level. Its average depth is {{convert|4280|m|fathom ft|abbr=on}}, putting the total water volume at roughly {{convert|710000000|km3|cumi}}.<ref name=ebc />

Due to the effects of [[plate tectonics]], the Pacific Ocean is currently shrinking by roughly {{convert |2.5|cm|in}} per year on three sides, roughly averaging {{convert|0.52|km2|sqmi|abbr=on}} a year. By contrast, the Atlantic Ocean is increasing in size.<ref>{{cite web |url = http://www.bucknell.edu/x17758.xml |title = Plate Tectonics |publisher = Bucknell University |archive-url = https://web.archive.org/web/20140225224202/http://www.bucknell.edu/x17758.xml |archive-date = 25 February 2014 |access-date = 9 June 2013 |url-status = live }}</ref><ref name="Young2009">{{cite book|last=Young|first=Greg|title=Plate Tectonics|url=https://books.google.com/books?id=aqTxe74R5LwC&pg=PT9|date=2009|publisher=Capstone|isbn=978-0-7565-4232-0|page=9}}</ref>

Along the Pacific Ocean's irregular western margins lie many seas, the largest of which are the [[Celebes Sea]], [[Coral Sea]], [[East China Sea]] (East Sea), [[Philippine Sea]], [[Sea of Japan]], [[South China Sea]] (South Sea), [[Sulu Sea]], [[Tasman Sea]], and [[Yellow Sea]] (West Sea of Korea). The [[Geology of Indonesia#Indonesian Seaway|Indonesian Seaway]] (including the [[Strait of Malacca]] and [[Torres Strait]]) joins the Pacific and the [[Indian Ocean]] to 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 [[Arctic Ocean]].<ref name="Organization1953">{{cite journal|author=International Hydrographic Organization|title=Limits of Oceans and Seas|journal=Nature|volume=172|issue=4376|page=484|url=https://books.google.com/books?id=wD0dAQAAIAAJ|date=1953|bibcode=1953Natur.172R.484.|doi=10.1038/172484b0 |doi-access=free}}</ref>

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]].<ref name="Lydia">{{cite book|author=Agno, Lydia|title=Basic Geography|url=https://books.google.com/books?id=HofX9zL4YQEC&pg=PA25|date=1998|publisher=Goodwill Trading Co., Inc.|isbn=978-971-11-0165-7|page=25}}</ref>

The Southern Pacific Ocean harbors the [[Southeast Indian Ridge]] crossing from south of Australia turning into the [[Pacific-Antarctic Ridge]] (north of the [[South Pole]]) and merges with another ridge (south of South America) to form the [[East Pacific Rise]] which also connects with another ridge (south of North America) which overlooks the [[Juan de Fuca Ridge]].

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 storm]]s batter the islands of the Pacific.<ref>[https://www.britannica.com/EBchecked/topic/437703/Pacific-Ocean/36086/The-trade-winds "Pacific Ocean: The trade winds"], ''Encyclopædia Britannica''. Retrieved 9 June 2013.</ref> The lands around the [[Pacific Rim]] are full of [[volcano]]es and often affected by [[earthquake]]s. [[Tsunami]]s, caused by underwater earthquakes, have devastated many islands and in some cases destroyed entire towns.<ref name="Bryant2008">{{cite book|last=Bryant|first=Edward|title=Tsunami: The Underrated Hazard|url=https://books.google.com/books?id=6lvl6i7r2CcC&pg=PR26|date=2008|publisher=Springer|isbn=978-3-540-74274-6|page=26}}</ref>

The [[Martin Waldseemüller]] map of 1507 was the first to show the Americas separating two distinct oceans.<ref>{{cite web|title=The Map That Named America|url=https://www.loc.gov/loc/lcib/0309/maps.html|website=loc.gov|access-date=3 December 2014}}</ref> Later, the [[Diogo Ribeiro (cartographer)|Diogo Ribeiro]] map of 1529 was the first to show the Pacific at about its proper size.<ref>{{Citation|last=Ribero|first=Diego|title=Carta universal en que se contiene todo lo que del mundo se ha descubierto fasta agora / hizola Diego Ribero cosmographo de su magestad, ano de 1529, e[n] Sevilla|url=http://nla.gov.au/nla.obj-230692844|publisher=W. Griggs|access-date=30 September 2017}}</ref>

=== Bordering countries ===
[[File:Map of the Territorial Waters of the Pacific Ocean.png|thumb|upright=1.6|An exclusive economic zone (EEZ) map of the Pacific]]
(Inhabited dependent territories are denoted by the asterisk (*), with names of the corresponding sovereign states in round brackets. Associated states in the Realm of New Zealand are denoted by the hash sign (#).)

=== Asia-Pacific ===
{{div col|colwidth=20em}}
* {{flag|American Samoa}}* (US)
* {{flag|Australia}}
* {{flag|Brunei}}
* {{flag|Cambodia}}
* {{flag|People's Republic of China}}
* {{flag|Cook Islands}} #
* {{flag|Federated States of Micronesia}}
* {{flag|Fiji}}
* {{flag|French Polynesia}}* (France)
* {{flag|Guam}}* (US)
* {{flag|Hong Kong}}* (People's Republic of China)
* {{flag|Indonesia}}
* {{flag|Japan}}
* {{flag|Kiribati}}
* {{flag|Macau}}* (People's Republic of China)
* {{flag|Malaysia}}
* {{flag|Marshall Islands}}
* {{flag|Nauru}}
* {{flag|New Caledonia|local}}* (France)
* {{flag|New Zealand}}
* {{flag|Niue}} #
* {{flag|Norfolk Island}}* (Australia)
* {{flag|Northern Mariana Islands}}* (US)
* {{flag|North Korea}}
* {{flag|Palau}}
* {{flag|Papua New Guinea}}
* {{flag|Philippines}}
* {{flag|Pitcairn Islands}}* (UK)
* {{flag|Russia}}
* {{flag|Samoa}}
* {{flag|Singapore}}
* {{flag|Solomon Islands}}
* {{flag|South Korea}}
* {{flag|Taiwan}}
* {{flag|Thailand}}
* {{flag|Timor-Leste}}
* {{flag|Tonga}}
* {{flag|Tokelau}}* (New Zealand)
* {{flag|Tuvalu}}
* {{flag|Vanuatu}}
* {{flag|Vietnam}}
* {{flag|Wallis and Futuna|local}}* (France)
{{div col end}}

=== Americas ===
{{div col|colwidth=20em}}
* {{flag|Canada}}
* {{flag|Chile}}
* {{flag|Colombia}}
* {{flag|Costa Rica}}
* {{flag|Ecuador}}
* {{flag|El Salvador}}
* {{flag|Guatemala}}
* {{flag|Honduras}}
* {{flag|Mexico}}
* {{flag|Nicaragua}}
* {{flag|Panama}}
* {{flag|Peru}}
* {{flag|United States}}
{{div col end}}

==== Uninhabited territories ====
Territories with no permanent civilian population.
{{div col|colwidth=20em}}
* {{flag|Baker Island}} (US)
* {{flag|Clipperton Island}} (France)
* {{flag|Coral Sea Islands}} (Australia)
* {{flag|Howland Island}} (US)
* {{flag|Jarvis Island}} (US)
* {{flag|Johnston Island}} (US)
* {{flag|Kingman Reef}} (US)
* {{flag|Macquarie Island}} (Australia)
* {{flag|Midway Atoll}} (US)
* {{flag|Palmyra Atoll}} (US)
* {{flag|Wake Island}} (US)
{{div col end}}

=== Landmasses and islands ===
{{Main|List of islands in the Pacific Ocean}}
[[File:South Tarawa from the air.jpg|thumb|[[Tarawa Atoll]] in [[Kiribati]]]]
The Pacific Ocean has most of the islands in the world. There are about 25,000 islands in the Pacific Ocean.<ref>{{cite web|last1=K|first1=Harsh|title=This ocean has most of the islands in the world|url=http://mysticalroads.com/pacific-ocean-facts/|website=Mysticalroads|access-date=6 April 2017|date=19 March 2017|url-status=dead|archive-url=https://web.archive.org/web/20170802153519/http://mysticalroads.com/pacific-ocean-facts/|archive-date=2 August 2017}}</ref><ref>{{cite book|last1=Ishihara|first1=Masahide|last2=Hoshino|first2=Eiichi|last3=Fujita|first3=Yoko|title=Self-determinable Development of Small Islands|date=2016|publisher=Springer|isbn=978-981-10-0132-1|page=180|url=https://books.google.com/books?id=3hNkDAAAQBAJ&pg=PA180|language=en}}</ref><ref>{{cite book|last1=United States. [[National Oceanic and Atmospheric Administration]]|last2=Western Pacific Regional Fishery Management Council|title=Toward an Ecosystem Approach for the Western Pacific Region: from Species-based Fishery Management Plans to Place-based Fishery Ecosystem Plans: Environmental Impact Statement|date=2009|publisher=Northwestern University|location=Evanston, IL|page=60|url=https://books.google.com/books?id=3Tw3AQAAMAAJ&pg=PA60|language=en|author2-link=Western Pacific Regional Fishery Management Council}}</ref> 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 center, the [[Marshall Islands]] to the east and the islands of [[Kiribati]] in the southeast.<ref name="AAE">{{cite book|title=Academic American encyclopedia|url=https://books.google.com/books?id=cF8NAQAAMAAJ|date=1997|publisher=Grolier Incorporated|isbn=978-0-7172-2068-7|page=8}}</ref><ref name="LalFortune2000p63">{{cite book|last1=Lal|first1=Brij Vilash|last2=Fortune|first2=Kate|title=The Pacific Islands: An Encyclopedia|url=https://books.google.com/books?id=T5pPpJl8E5wC&pg=PA63|date=2000|publisher=University of Hawaii Press|isbn=978-0-8248-2265-1|page=63}}</ref>

Melanesia, to the southwest, includes [[New Guinea]], the world's second largest island after [[Greenland]] and by far the largest of the Pacific islands. The other main Melanesian groups from north to south are the [[Bismarck Archipelago]], the [[Solomon Islands]], [[Santa Cruz Islands|Santa Cruz]], [[Vanuatu]], [[Fiji]] and [[New Caledonia]].<ref name="West2009">{{cite book|last=West|first=Barbara A.|title=Encyclopedia of the Peoples of Asia and Oceania|url=https://books.google.com/books?id=pCiNqFj3MQsC&pg=PA521|date=2009|publisher=Infobase Publishing|isbn=978-1-4381-1913-7|page=521}}</ref>

The largest area, [[Polynesia]], stretching from [[Hawaii]] in the north to New Zealand in the south, also encompasses [[Tuvalu]], [[Tokelau]], [[Samoa]], [[Tonga]] and the [[Kermadec Islands]] to the west, the [[Cook Islands]], [[Society Islands]] and [[Austral Islands]] in the center, and the [[Marquesas Islands]], [[Tuamotus|Tuamotu]], [[Mangareva Islands]], and [[Easter Island]] to the east.<ref name="DunfordRidgell1996">{{cite book|last1=Dunford|first1=Betty|last2=Ridgell|first2=Reilly|title=Pacific Neighbors: The Islands of Micronesia, Melanesia, and Polynesia|url=https://books.google.com/books?id=3n2z7E1zH3MC|date=1996|publisher=Bess Press|isbn=978-1-57306-022-6|page=125}}</ref>

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 Island|Bougainville]], Hawaii, and the Solomon Islands.<ref name="GillespieClague2009">{{cite book|last1=Gillespie|first1=Rosemary G.|last2=Clague|first2=David A.|title=Encyclopedia of Islands|url=https://books.google.com/books?id=g9ZogGs_fz8C&pg=PA706|date=2009|publisher=University of California Press|isbn=978-0-520-25649-1|page=706}}</ref>

The [[coral reef]]s of the South Pacific 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 with chains of reef patches. 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 Island|Banaba]] (formerly Ocean Island) and [[Makatea]] in the Tuamotu group of [[French Polynesia]].<ref>[https://www.britannica.com/EBchecked/topic/137072/coral-island "Coral island"], ''Encyclopædia Britannica''. Retrieved 22 June 2013.</ref><ref>{{cite web|url=http://www.abc.net.au/ra/pacific/places/country/nauru.htm |title =Nauru|website = Charting the Pacific|publisher = ABC Radio Australia|date = 2005}}</ref>

<gallery widths="180px" heights="120px">
File:Ladrilleros Beach Colombia.jpg|Ladrilleros Beach in [[Colombia]] on the coast of [[Pacific/Chocó natural region|Chocó natural region]]
File:Tahuna maru islet Raroia.jpg|Tahuna maru islet, [[French Polynesia]]
File:Los Molinos.JPG|[[Los Molinos, Chile|Los Molinos]] on the coast of [[Zona Sur|Southern Chile]]
</gallery>

== Water characteristics ==
[[File:Sunset Marina.JPG|thumb|Sunset in [[Monterey County, California]], U.S.]]
The volume of the Pacific Ocean, representing about 50.1 percent of the world's oceanic water, has been estimated at some {{convert|714|e6km3|e6cumi|sp=us|abbr=off}}.<ref>{{cite web|url=http://www.pwlf.org/pacific.htm |title=PWLF.org – The Pacific WildLife Foundation – The Pacific Ocean |access-date=23 August 2013 |url-status=dead |archive-url=https://web.archive.org/web/20120421015555/http://www.pwlf.org/pacific.htm |archive-date=21 April 2012 }}</ref> Surface water temperatures in the Pacific can vary from {{convert|-1.4|°C|°F|abbr=on}}, the freezing point of seawater, in the poleward areas to about {{convert|30|°C|°F|abbr=on}} near the equator.<ref name="Mongillo2000">{{cite book|last=Mongillo|first=John F.|title=Encyclopedia of Environmental Science|url=https://books.google.com/books?id=ozAN5vLbssgC&pg=PA255|date=2000|publisher=University Rochester Press|isbn=978-1-57356-147-1|page=255}}</ref> [[Salinity]] also varies latitudinally, reaching a maximum of 37 parts per thousand in the southeastern area. The water near the equator, which can have a salinity as low as 34 parts per thousand, is less salty than that found in the mid-latitudes because of abundant equatorial precipitation throughout the year. The lowest counts of less than 32 parts per thousand are found in the far north as less evaporation of seawater takes place in these frigid areas.<ref>[https://www.britannica.com/EBchecked/topic/437703/Pacific-Ocean/36092/Salinity "Pacific Ocean: Salinity"], ''Encyclopædia Britannica''. Retrieved 9 June 2013.</ref> The motion of Pacific waters is generally clockwise in the [[Northern Hemisphere]] (the [[Ocean gyre|North Pacific gyre]]) and counter-clockwise in the [[Southern Hemisphere]]. The [[North Equatorial Current]], driven westward along [[15th parallel north|latitude 15°N]] by the [[trade winds]], turns north near the Philippines to become the warm Japan or [[Kuroshio Current]].<ref>[http://oceanmotion.org/html/background/equatorial-currents.htm "Wind Driven Surface Currents: Equatorial Currents Background"], Ocean Motion. Retrieved 9 June 2013.</ref>

Turning eastward at about [[45th parallel north|45°N]], the Kuroshio forks and some water moves northward as the [[Aleutian Current]], while the rest turns southward to rejoin the North Equatorial Current.<ref>[https://www.britannica.com/EBchecked/topic/325346/Kuroshio "Kuroshio"], ''Encyclopædia Britannica''. Retrieved 9 June 2013.</ref> 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]].<ref>[https://www.britannica.com/EBchecked/topic/13933/Aleutian-Current "Aleutian Current"], ''Encyclopædia Britannica''. Retrieved 9 June 2013.</ref> The [[South Equatorial Current]], flowing west along the equator, swings southward east of [[New Guinea]], turns east at about [[50th parallel south|50°S]], and joins the main westerly circulation of the South 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]].<ref>[https://www.britannica.com/EBchecked/topic/437770/Pacific-South-Equatorial-Current "South Equatorial Current"], ''Encyclopædia Britannica''. Retrieved 9 June 2013.</ref>

== Climate ==
[[File:El nino north american weather.png|thumb|upright=1.1|Impact of [[El Niño]] and [[La Niña]] on North America]]
[[File:Tip 1979-10-12 0533Z.png|thumb|[[Typhoon Tip]] at global peak intensity on 12 October 1979]]
The climate patterns of the Northern and Southern Hemispheres generally mirror each other. The [[trade winds]] in the southern and eastern Pacific are remarkably steady while conditions in the North Pacific are far more varied with, for example, cold winter temperatures on the east coast of Russia contrasting with the milder weather off [[British Columbia]] during the winter months due to the preferred flow of [[ocean current]]s.<ref>[https://www.britannica.com/EBchecked/topic/437703/Pacific-Ocean/36083/Islands#toc36085 "Pacific Ocean: Islands"], ''Encyclopædia Britannica''. Retrieved 13 June 2013.</ref>

In the tropical and subtropical Pacific, the [[El Niño Southern Oscillation]] (ENSO) affects weather conditions. To determine the phase of ENSO, the most recent three-month [[sea surface temperature]] average for the area approximately {{convert|3000|km|mi|abbr=on}} to the southeast of [[Hawaii]] is computed, and if the region is more than {{convert|0.5|C-change|1}} above or below normal for that period, then an [[El Niño]] or [[La Niña]] is considered in progress.<ref>{{cite web|url=http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf|title=ENSO: Recent Evolution, Current Status and Predictions|pages=5, 19–20|author=Climate Prediction Center |author-link=Climate Prediction Center|publisher=[[National Oceanic and Atmospheric Administration]]|date=30 June 2014|access-date=30 June 2014}}</ref>

In September 2025, NOAA reported that global ocean surface temperatures remained at near-record levels, with June–August 2025 ranking as the third warmest in their 176-year record.<ref>{{cite web |date=September 2025 |title=Assessing the Global Climate in August 2025 |url=https://www.ncei.noaa.gov/news/global-climate-202508 |access-date=2025-10-02 |publisher=NOAA National Centers for Environmental Information}}</ref>

In the tropical western Pacific, the [[monsoon]] and the related [[wet season]] during the summer months contrast with dry winds in the winter which blow over the ocean from the Asian landmass.<ref>Glossary of Meteorology (2009). [http://amsglossary.allenpress.com/glossary/search?p=1&query=monsoon&submit=Search Monsoon.] {{webarchive|url=https://web.archive.org/web/20080322122025/http://amsglossary.allenpress.com/glossary/search?p=1&query=monsoon&submit=Search |date=22 March 2008 }} American Meteorological Society. Retrieved on 16 January 2009.</ref> Worldwide, [[tropical cyclone]] activity peaks in late summer, when the difference between temperatures aloft and sea surface temperatures is the greatest; however, each particular basin has its own seasonal patterns. On a worldwide scale, May is the least active month, while September is the most active month. November is the only month in which all the [[tropical cyclone basins]] are active.<ref name="AOML FAQ G1">{{cite web|title=Frequently Asked Questions: When is hurricane season?|publisher=[[National Oceanic and Atmospheric Administration]]|access-date=25 July 2006|url=http://www.aoml.noaa.gov/hrd/tcfaq/G1.html|author1 = Atlantic Oceanographic and Meteorological Laboratory – Hurricane Research Division|author-link1=Atlantic Oceanographic and Meteorological Laboratory}}</ref> The Pacific hosts the two most active [[tropical cyclone basins]], which are the northwestern Pacific and the eastern Pacific. [[Pacific hurricane]]s form south of Mexico, sometimes striking the western Mexican coast and occasionally the Southwestern United States between June and October, while [[typhoon]]s forming in the northwestern Pacific moving into southeast and east Asia from May to December. Tropical cyclones also form in the [[South Pacific tropical cyclone|South Pacific basin]], where they occasionally impact island nations.<ref>{{cite book |last1=Chand |first1=Savin S. |last2=Dowdy |first2=Andrew |last3=Bell |first3=Samuel |last4=Tory |first4=Kevin |title=Climate Change and Impacts in the Pacific |chapter=A Review of South Pacific Tropical Cyclones: Impacts of Natural Climate Variability and Climate Change |series=Springer Climate |date=2020 |pages=251–273 |doi=10.1007/978-3-030-32878-8_6 |isbn=978-3-030-32877-1 }}</ref>

In the arctic, icing from October to May can present a hazard for shipping while persistent fog occurs from June to December.<ref>[https://web.archive.org/web/20260115154309/https://www.cia.gov/the-world-factbook/oceans/pacific-ocean/ "Pacific Ocean"], ''World Factbook'', CIA. Retrieved 13 June 2013.</ref> A climatological low in the Gulf of Alaska keeps the southern coast wet and mild during the winter months. The [[Westerlies]] and associated [[jet stream]] within the Mid-Latitudes can be particularly strong, especially in the Southern Hemisphere, due to the temperature difference between the tropics and Antarctica,<ref name="Stimac">John P. Stimac. [http://www.ux1.eiu.edu/~cfjps/1400/pressure_wind.html Air pressure and wind.] Retrieved on 8 May 2008.</ref> which records the coldest temperature readings on the planet. In the Southern hemisphere, because of the stormy and cloudy conditions associated with [[extratropical cyclone]]s riding the jet stream, it is usual to refer to the Westerlies as the Roaring Forties, Furious Fifties and Shrieking Sixties according to the varying degrees of latitude.<ref>{{cite book|last=Walker|first=Stuart|title=The sailor's wind |publisher=W.W. Norton & Company|date=1998|page=[https://archive.org/details/sailorswind00walk/page/91 91]|isbn=978-0-393-04555-0|url=https://archive.org/details/sailorswind00walk|url-access=registration}}</ref>

== Geology ==
{{Main|Geology of the Pacific Ocean|Pacific plate}}
[[File:Pacific Ring of Fire.svg|thumb|upright=1.75|A [[Ring of Fire]]; the Pacific is ringed by many volcanoes and [[oceanic trench]]es. This map does not show the [[Cascadia subduction zone]] along part of the west coast of North America, whose trench is completely buried in sediments.]]
[[File:Ulawun.jpg|thumb|A [[stratovolcano]] in [[Ulawun]] on the island of [[New Britain]] in [[Papua New Guinea]]]]
[[File:Mount Saint Helens, June 2020.jpg|thumb|[[Mount St. Helens]] in [[Skamania County, Washington]], U.S. in 2020]]
The ocean was first mapped by [[Abraham Ortelius]]; he called it Maris Pacifici following [[Ferdinand Magellan]]'s description of it as "a pacific sea" during his circumnavigation from 1519 to 1522. To Magellan, it seemed much more calm (pacific) than the Atlantic.<ref name="Library2006">{{cite book|author=Turnbull, Alexander |title=Map New Zealand: 100 Magnificent Maps from the Collection of the Alexander Turnbull Library|url=https://books.google.com/books?id=227gAAAAMAAJ|year=2006|publisher=Godwit|isbn=978-1-86962-126-1|page=8}}</ref>

The [[andesite line]] is the most significant regional distinction in the Pacific. A petrologic boundary, 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.<ref name="TrentHazlett2010">{{cite book|last1=Trent|first1=D. D.|last2=Hazlett|first2=Richard|last3=Bierman|first3=Paul|title=Geology and the Environment|url=https://books.google.com/books?id=TbGOhr9Po9IC&pg=PA133|date=2010|publisher=Cengage Learning|isbn=978-0-538-73755-5|page=133}}</ref> The andesite line follows the western edge of the islands off California and passes south of the [[Aleutian Islands|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]].<ref name="LalFortune2000p4">{{cite book|last1=Lal|first1=Brij Vilash|last2=Fortune|first2=Kate|title=The Pacific Islands: An Encyclopedia|url=https://books.google.com/books?id=T5pPpJl8E5wC&pg=PA4|year=2000|publisher=University of Hawaii Press|isbn=978-0-8248-2265-1|page=4}}</ref><ref name="Mueller-Dombois1998">{{cite book|last=Mueller-Dombois|first=Dieter|title=Vegetation of the Tropical Pacific Islands|url=https://books.google.com/books?id=7UB5d33i8WkC&pg=PA13|date=1998|publisher=Springer|isbn=978-0-387-98313-4|page=13}}</ref>

The dissimilarity continues northeastward along the western edge of the [[Andes]] [[American Cordillera|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]].<ref name="AAE" /> 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 mostly bounded by [[subduction]] zones. Only the central part of the North American coast and the Antarctic and Australian coasts have no nearby subduction zones.

=== Geological history ===
The Pacific Ocean was born 750{{spaces}}million years ago at the breakup of [[Rodinia]], although it is generally called the [[Panthalassa]] until the breakup of [[Pangea]], about 200{{spaces}}million years ago.<ref name="geol.umd.edu">{{cite web|url=http://www.geol.umd.edu/~tholtz/G102/102prot2.htm |title=GEOL 102 The Proterozoic Eon II: Rodinia and Pannotia |publisher=Geol.umd.edu |date=5 January 2010 |access-date=31 October 2010}}</ref> The oldest Pacific Ocean floor is only around 180 [[Mega-annum|Ma]] old, with older crust subducted by now.<ref name="MussettKhan2000">{{cite book|last1=Mussett|first1=Alan E.|last2=Khan|first2=M. Aftab|title=Looking into the Earth: An Introduction to Geological Geophysics|url=https://books.google.com/books?id=nzJLiPjHvCQC&pg=PA332|year= 2000|publisher=Cambridge University Press|isbn=978-0-521-78574-7|page=332}}</ref>

=== Seamount chains ===
The Pacific Ocean contains several long [[seamount]] chains, formed by [[Hotspot (geology)|hotspot volcanism]]. These include the [[Hawaiian–Emperor seamount chain]] and the [[Louisville Ridge]].

== Economy ==
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 [[pearl]]s are harvested along the coasts of Australia, Japan, [[Papua New Guinea]], Nicaragua, Panama, and the Philippines, although in sharply declining volume in some cases.<ref>[https://www.britannica.com/EBchecked/topic/437703/Pacific-Ocean/36099/Fisheries "Pacific Ocean: Fisheries"], ''Encyclopædia Britannica''. Retrieved 12 June 2013.</ref>

=== Fishing ===
[[Fish]] are an important economic asset in the Pacific. The shallower shoreline waters of the continents and the more temperate islands yield [[herring]], [[salmon]], [[sardine]]s, [[Australasian snapper|snapper]], [[swordfish]], and [[tuna]], as well as [[shellfish]].<ref>[https://www.infoplease.com/encyclopedia/places/other/oceans-continents/pacific-ocean/commerce-and-shipping "Pacific Ocean: Commerce and Shipping"], ''The Columbia Electronic Encyclopedia'', 6th edition. Retrieved 14 June 2013.</ref> [[Overfishing]] has become a serious problem in some areas. Overfishing leads to depleted fish populations and closed fisheries, causing both economic and ecologic consequences.<ref>{{Cite journal |last=Burgess |first=Matthew G |date=16 September 2013 |title=Predicting overfishing and extinction threats in multispecies fisheries |journal=Proceedings of the National Academy of Sciences |volume=110 |issue=40 |pages=15943–15948 |doi=10.1073/pnas.1314472110 |doi-access=free |pmid=24043810 |pmc=3791778 |bibcode=2013PNAS..11015943B }}</ref> For example, catches in the rich fishing grounds of the [[Sea of Okhotsk|Okhotsk Sea]] off the Russian coast have been reduced by at least half since the 1990s as a result of overfishing.<ref>[http://centerforoceansolutions.org/?q=projects/pacific-ocean-initiative/major-threats-pacific-ocean/overfishing-and-exploitation "Pacific Ocean Threats & Impacts: Overfishing and Exploitation"] {{webarchive|url=https://web.archive.org/web/20130512140621/http://www.centerforoceansolutions.org/?q=projects%2Fpacific-ocean-initiative%2Fmajor-threats-pacific-ocean%2Foverfishing-and-exploitation|date=12 May 2013}}, Center for Ocean Solutions. Retrieved 14 June 2013.</ref>

== Environment ==
{{See also|Great Pacific Garbage Patch|Environmental impact of shipping}}
[[File:Pacific-garbage-patch-map 2010 noaamdp.jpg|thumb|upright=1.5|Pacific Ocean currents have created three islands of debris.<ref>{{Cite web|url=https://marinedebris.noaa.gov/movement/great-pacific-garbage-patch|title=Great Pacific Garbage Patch|website=Marine Debris Division – Office of Response and Restoration|publisher=NOAA|url-status=live|archive-url=https://web.archive.org/web/20140417124654/https://marinedebris.noaa.gov/movement/great-pacific-garbage-patch|archive-date=17 April 2014|date=11 July 2013}}</ref>]]
[[File:Marine debris on Hawaiian coast.jpg|thumb|[[Marine debris]] on a [[Hawaii]]an coast in 2008]]
The Northwestern Pacific Ocean is most susceptible to micro plastic pollution due to its proximity to highly populated countries like Japan and China.<ref>{{cite journal |last1=Pan |first1=Zhong |last2=Liu |first2=Qianlong |last3=Sun |first3=Yan |last4=Sun |first4=Xiuwu |last5=Lin |first5=Hui |title=Environmental implications of microplastic pollution in the Northwestern Pacific Ocean |journal=Marine Pollution Bulletin |date=September 2019 |volume=146 |pages=215–224 |doi=10.1016/j.marpolbul.2019.06.031 |pmid=31426149 |bibcode=2019MarPB.146..215P }}</ref> The quantity of small plastic fragments floating in the north-east Pacific Ocean increased a hundredfold between 1972 and 2012.<ref>[https://www.bbc.co.uk/news/uk-18099937 Plastic waste in the North Pacific is an ongoing concern] BBC 9 May 2012</ref>{{Verification needed|date=September 2025}} The ever-growing [[Great Pacific Garbage Patch]] between California and Japan is three times the size of France.<ref>{{cite news|title='Great Pacific Garbage Patch' is massive floating island of plastic, now 3 times the size of France|url=https://abcnews.go.com/International/great-pacific-garbage-patch-massive-floating-island-plastic/story?id=53962147|publisher=ABC News|location=United States|date=23 March 2018}}</ref> An estimated 80,000 metric tons of plastic inhabit the patch, totaling 1.8{{spaces}}trillion pieces.<ref>{{cite news|title='Great Pacific garbage patch' 16 times bigger than previously thought, say scientists|url=https://www.independent.co.uk/climate-change/news/great-pacific-garbage-patch-plastic-pollution-oceans-environment-fish-a8269951.html |archive-url=https://ghostarchive.org/archive/20220524/https://www.independent.co.uk/climate-change/news/great-pacific-garbage-patch-plastic-pollution-oceans-environment-fish-a8269951.html |archive-date=24 May 2022 |url-access=subscription |url-status=live|work=The Independent|date=23 March 2018}}</ref>

[[Marine pollution]] is a generic term for the harmful entry into the ocean of chemicals or particles. The main culprits are those using the rivers for disposing of their waste.<ref name="news.nationalgeographic.com">{{cite web|url=https://news.nationalgeographic.com/news/2009/09/photos-giant-ocean-trash-vortex-documented-a-first|title=Photos: Giant Ocean-Trash Vortex Documented – A First|first=Brian|last=Handwerk|publisher=National Geographic|date=4 September 2009|archive-url=https://web.archive.org/web/20101119153734/http://news.nationalgeographic.com/news/2009/09/photogalleries/pacific-garbage-patch-pictures/|archive-date=19 November 2010|url-status=dead}}</ref> The rivers then empty into the ocean, often also bringing chemicals used as [[fertilizer]]s in agriculture. The excess of oxygen-depleting chemicals in the water leads to [[hypoxia (environmental)|hypoxia]] and the creation of a [[dead zone (ecology)|dead zone]].<ref>{{cite book|last = Gerlach|first = Sebastian A.|title = Marine Pollution|publisher= Springer|location = Berlin |date =1975|language = de}}</ref>

[[Marine debris]], also known as marine litter, is human-created waste that has ended up floating in a lake, sea, ocean, or waterway. Oceanic debris tends to accumulate at the center of gyres and coastlines, frequently washing aground where it is known as beach litter.<ref name="news.nationalgeographic.com" />

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

=== Nuclear waste ===
[[File:20200926fukushima01.jpg|thumb|In 2020, [[Yoshihide Suga|Japanese Prime Minister Suga]] declined to drink the bottle of [[Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant|Fukushima's treated radioactive water]] that he was holding, which would otherwise be discharged to the Pacific.<ref name="Asahi Shimbun 20201103">{{cite news|title=原発の処理水、菅首相「飲んでもいい?」 東電の説明は|trans-title=Prime Minister Suga asks if the treated radioactive water is drinkable. Here is TEPCO's response|newspaper=[[The Asahi Shimbun]]|date=3 November 2020|last=大月規義|url=https://www.asahi.com/articles/ASNC255HSNBZULZU00G.html}}</ref>]]
From 1946 to 1958, [[Marshall Islands]] served as the [[Pacific Proving Grounds]], designated by the United States, and played host to a total of 67 [[nuclear test]]s conducted across various atolls.<ref>{{Cite web|url=https://www.rnz.co.nz/international/pacific-news/325643/marshall-islands-marks-71-years-since-start-of-us-nuclear-tests-on-bikini|title=Marshall Islands marks 71 years since start of US nuclear tests on Bikini|date=1 March 2017|website=Radio New Zealand|language=en-nz}}</ref><ref>{{cite web|first=Renee|last=Lewis|title=Bikinians evacuated 'for good of mankind' endure lengthy nuclear fallout|url=http://america.aljazeera.com/articles/2015/7/28/bikini-nuclear-test-survivors-demand-compensation.html|publisher=Al Jazeera|date=28 July 2015}}</ref> Several [[nuclear weapon]]s were lost in the Pacific Ocean,<ref>{{cite news|last=Thaler|first=Andrew David|title=How many nuclear weapons are at the bottom of the sea. An (almost certainly incomplete) census of broken arrows over water.|url=http://www.southernfriedscience.com/how-many-nuclear-weapons-are-at-the-bottom-of-the-sea-an-almost-certainly-incomplete-census-of-broken-arrows-over-water/|publisher=Southern Fried Science|date=26 July 2018}}</ref> including one-megaton bomb that was lost during the [[1965 Philippine Sea A-4 incident]].<ref>{{cite news|title=U.S. discloses accidents involving nuclear weapons|first=Richard|last=Halloran|newspaper=The New York Times|date=26 May 1981|url=https://www.nytimes.com/1981/05/26/us/us-discloses-accidents-involving-nuclear-weapons.html}}</ref>

In 2021, the [[Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant|discharge of radioactive water from the Fukushima nuclear plant]] into the Pacific Ocean over a course of 30 years was approved by the Japanese Cabinet. The Cabinet concluded the radioactive water would have been diluted to drinkable standard.<ref name="BBC 20210413">{{cite news|title=Fukushima: Japan approves releasing wastewater into ocean|publisher=BBC|date=13 April 2021|url=https://www.bbc.com/news/world-asia-56728068}}</ref> Apart from dumping, [[Leakage of radioactive water of the Fukushima Daiichi Nuclear Power Plant|leakage of tritium into the Pacific]] was estimated to be between 20 and 40 trillion [[becquerel|Bq]]s from 2011 to 2013, according to the Fukushima plant.<ref name="Scientific American 20130813">{{cite news|title=Radioactive Water Leaks from Fukushima: What We Know|newspaper=[[Scientific American]]|date=13 August 2013|last=Hsu|first=Jeremy|url=https://www.scientificamerican.com/article/radioactive-water-leaks-from-fukushima/}}</ref>

=== Deep sea mining ===
An emerging threat for the Pacific Ocean is the development of [[deep-sea mining]].
Deep-sea mining is aimed at extracting [[manganese nodules]] that contain minerals such as magnesium, nickel, copper, zinc and cobalt. The largest deposits of these are found in the Pacific Ocean between Mexico and Hawaii in the [[Clarion Clipperton fracture zone]].

Deep-sea mining for manganese nodules appears to have drastic consequences for the ocean. It disrupts deep-sea ecosystems and may cause irreversible damage to fragile marine habitats.<ref name="Halfar2007">{{cite journal |last1=Halfar |first1=Jochen |last2=Fujita |first2=Rodney M. |title=Danger of Deep-Sea Mining |journal=Science |date=18 May 2007 |volume=316 |issue=5827 |pages=987–987 |doi=10.1126/science.1138289 |pmid=17510349 }}<!-- auto-translated from Dutch by Module:CS1 translator --></ref> Sediment stirring and chemical pollution threaten various marine animals. In addition, the mining process can lead to greenhouse gas emissions and promote further climate change. Preventing deep-sea mining is therefore important to ensure the long-term health of the ocean.<ref>{{cite web|archive-date=3 June 2020|archive-url=https://web.archive.org/web/20200603005737/http://www.deepseaminingoutofourdepth.org/impacts-of-mining-deep-sea-polymetallic-nodules-in-the-pacific|url=http://www.deepseaminingoutofourdepth.org/impacts-of-mining-deep-sea-polymetallic-nodules-in-the-pacific/|title=Impacts of mining deep sea polymetallic nodules in the Pacific Ocean &#124; Deep Sea Mining: Out of Our Depth|work=Deep Sea Mining: Out Of Our Depth |date=19 May 2020 }}</ref>

=== List of major ports ===
{{Div col|colwidth=10em}}
* [[Acapulco]]
* [[Auckland]]
* [[Bangkok]]
* [[Busan]]
* [[Callao]]
* [[Cebu City]]
* [[Dalian]]
* [[Guangzhou]]
* [[Guayaquil]]
* [[Haiphong]]
* [[Ho Chi Minh City]]
* [[Hong Kong]]
* [[Honolulu]]
* [[Jakarta]]
* [[Johor Bahru]]
* [[Kaohsiung]]
* [[Keelung]]
* [[Long Beach, California|Long Beach]]
* [[Los Angeles]]
* [[Manzanillo, Colima|Manzanillo]]
* [[Manila]]
* [[Manta, Ecuador|Manta]]
* [[Melbourne]]
* [[Nagoya]]
* [[Nakhodka]]
* [[Oakland]]
* [[Osaka]]
* [[Panama City]]
* [[Portland, Oregon|Portland]]
* [[San Diego]]
* [[San Francisco]]
* [[Seattle]]
* [[Shanghai]]
* [[Singapore]]
* [[Sydney]]
* [[Tianjin]]
* [[Tokyo]]
* [[Valparaíso]]
* [[Vancouver]]
* [[Vladivostok]]
* [[Yokohama]]
{{Div col end}}

== See also ==
{{div col}}
* [[Asia-Pacific Economic Cooperation]]
* {{slink|List of seas on Earth#Pacific Ocean}}
* [[List of rivers of the Americas by coastline#Pacific Ocean coast]]
* [[List of ports and harbors of the Pacific Ocean]]
* [[Pacific Alliance]]
* [[Pacific coast]]
* [[Pacific Time Zone]]
* [[Seven Seas]]
* [[Trans-Pacific Partnership]]
* [[War of the Pacific]]
* [[Shackleton fracture zone]]
* [[Natural delimitation between the Pacific and South Atlantic oceans by the Scotia Arc]]
{{div col end}}
{{Portal bar|Oceans|Environment|Ecology|Geography|Weather}}

== References ==
{{Reflist}}

== Further reading ==
{{refbegin|30em}}
* {{Cite book|last=Barkley|first=Richard A.|title=Oceanographic Atlas of the Pacific Ocean|date=1968|publisher=[[University of Hawaii Press]]|location=Honolulu}}
* {{Cite book|title=Blue Horizons: Paradise Isles of the Pacific|date=1985|publisher=[[National Geographic Society]]|location=Washington, DC|isbn=978-0-87044-544-6|author=prepared by the Special Publications Division, National Geographic Society.}}
* {{Cite book|last=Cameron|first=Ian|title=Lost Paradise: The Exploration of the Pacific|date=1987|publisher=Salem House|location=Topsfield, MA|isbn=978-0-88162-275-1|url=https://archive.org/details/lostparadiseexpl00came}}
* {{Cite book|editor-last=Couper|editor-first=A.D. |title=Development and Social Change in the Pacific Islands|year=1989|publisher=Routledge|location=London|isbn=978-0-415-00917-1}}
* {{Cite book|last=Gilbert|first=John|title=Charting the Vast Pacific|year=1971|publisher=Aldus|location=London|isbn=978-0-490-00226-5}}
* {{Cite book|last=Igler|first=David|title=The Great Ocean: Pacific Worlds from Captain Cook to the Gold Rush|date=2013|publisher=Oxford University Press|location=New York|isbn=978-0-19-991495-1}}
* Jones, Eric, Lionel Frost, and Colin White. ''Coming Full Circle: An Economic History of the Pacific Rim'' (Westview Press, 1993)
* {{Cite book|last=Lower|first=J. Arthur|title=Ocean of Destiny: A Concise History of the North Pacific, 1500–1978|date=1978|publisher=[[University of British Columbia Press]]|location=Vancouver|isbn=978-0-7748-0101-0|url=https://archive.org/details/oceanofdestinyco0000lowe}}
* {{cite book |last=Mares |first=D.R. |title=Violent peace: Militarized interstate bargaining in Latin America |publisher=Columbia University Press|chapter=The Myth of Hegemonic Management |year=2001 |doi=10.7312/mare11186|pages=}}
* {{Cite book|last=Napier|first=W.|author2=Gilbert, J. |author3=Holland, J. |title=Pacific Voyages|year=1973|publisher=Doubleday|location=Garden City, NY|isbn=978-0-385-04335-9}}
* {{cite book|last=Nunn|first=Patrick D.|title=Pacific Island Landscapes: Landscape and Geological Development of Southwest Pacific Islands, Especially Fiji, Samoa and Tonga|url=https://books.google.com/books?id=AN8486A8fMcC&pg=PA15|year=1998|publisher=editorips@usp.ac.fj|isbn=978-982-02-0129-3}}
* {{Cite book|last=Oliver|first=Douglas L.|title=The Pacific Islands|year=1989|edition=3rd|publisher=University of Hawaii Press|location=Honolulu|isbn=978-0-8248-1233-1}}
* Paine, Lincoln. ''The Sea and Civilization: A Maritime History of the World'' (2015).
* {{Cite book|last=Ridgell|first=Reilly|title=Pacific Nations and Territories: The Islands of Micronesia, Melanesia, and Polynesia|year=1988|edition=2nd|publisher=Bess Press|location=Honolulu|isbn=978-0-935848-50-2}}
* Samson, Jane. ''British imperial strategies in the Pacific, 1750–1900'' (Ashgate Publishing, 2003).
* {{Cite book|last=Soule|first=Gardner|title=The Greatest Depths: Probing the Seas to 20,000 feet and below|year=1970|publisher=Macrae Smith|location=Philadelphia|isbn=978-0-8255-8350-6|url=https://archive.org/details/greatestdepthspr00soul}}
* {{Cite book|last=Spate|first=O.H.K.|title=Paradise Found and Lost|year=1988|publisher=[[University of Minnesota Press]]|location=Minneapolis|isbn=978-0-8166-1715-9}}
* {{Cite book|last=Terrell|first=John|title=Prehistory in the Pacific Islands: A Study of Variation in Language, Customs, and Human Biology|date=1986|publisher=Cambridge University Press|location=Cambridge|isbn=978-0-521-30604-1}}

=== Historiography ===
* Calder, Alex, et al. eds. '' Voyages and Beaches: Pacific Encounters, 1769–1840'' (U of Hawai'i Press, 1999)
* Davidson, James Wightman. "Problems of Pacific history." ''Journal of Pacific History'' 1#1 (1966): 5–21.
* {{Cite EB1911|wstitle= Pacific Ocean | volume= 20 |last1= Dickson |first1= Henry Newton |author1-link= Henry Newton Dickson | pages = 434–441 |short=1}}
* Dirlik, Arif. "The Asia-Pacific Idea: Reality and Representation in the Invention of a Regional Structure", ''Journal of World History'' 3#1 (1992): 55–79.
* Dixon, Chris, and David Drakakis-Smith. "The Pacific Asian Region: Myth or Reality?" ''Geografiska Annaler: Series B, Human Geography'' 77#@ (1995): 75+
* Dodge, Ernest S. ''New England and the South Seas'' (Harvard UP, 1965).
* Flynn, Dennis O., Arturo Giráldez, and James Sobredo, eds. ''Studies in Pacific History: Economics, Politics, and Migration'' (Ashgate, 2002).
* Gulliver, Katrina. "Finding the Pacific world." ''Journal of World History'' 22#1 (2011): 83–100. [https://www.academia.edu/241829/Finding_the_Pacific_World online]
* Korhonen, Pekka. "The Pacific Age in World History", ''Journal of World History'' 7#1 (1996): 41–70.
* Munro, Doug. ''The Ivory Tower and Beyond: Participant Historians of the Pacific'' (Cambridge Scholars Publishing, 2009).
* "Recent Literature in Discovery History." ''Terrae Incognitae'', annual feature in January issue since 1979; comprehensive listing of new books and articles.
* Routledge, David. "Pacific history as seen from the Pacific Islands." ''Pacific Studies'' 8#2 (1985): 81+ [https://web.archive.org/web/20160923134705/https://journals.lib.byu.edu/spc/index.php/PacificStudies/article/viewFile/9369/9018 online]
* Samson, Jane. "Pacific/Oceanic History" in {{cite book|editor-first=Kelly|editor-last=Boyd|title=Encyclopedia of Historians and Historical Writing vol 2|url=https://books.google.com/books?id=0121vD9STIMC&pg=PA901|year=1999|publisher=Taylor & Francis|pages=901–902|isbn=978-1-884964-33-6}}
* Stillman, Amy Ku'uleialoha. "Pacific-ing Asian Pacific American History", ''Journal of Asian American Studies'' 7#3 (2004): 241–270.
{{refend}}

== External links ==
{{sister project links|d=Q98|c=Category:Pacific Ocean|n=no|b=no|v=no|voy=no|m=no|mw=no|s=no|wikt=Pacific Ocean|species=no}}
* [https://web.archive.org/web/20100504012429/http://www.epic.noaa.gov/epic/ewb/ EPIC Pacific Ocean Data Collection Viewable] on-line collection of observational data
* [https://web.archive.org/web/20060211015453/http://dapper.pmel.noaa.gov/dchart/ NOAA In-situ Ocean Data Viewer] plot and download ocean observations
* [https://web.archive.org/web/20060210183949/http://floats.pmel.noaa.gov/floats/ NOAA PMEL Argo profiling floats Realtime Pacific Ocean data]
* [https://www.pmel.noaa.gov/tao/drupal/disdel/ NOAA TAO] [[El Niño]] data Realtime Pacific Ocean El Niño buoy data
* [https://web.archive.org/web/20051229005041/http://www.oscar.noaa.gov/datadisplay/ NOAA Ocean Surface Current Analyses] – Realtime (OSCAR) Near-realtime Pacific Ocean Surface Currents derived from satellite altimeter and scatterometer data

{{Regions of the world}}
{{Authority control}}

[[Category:Pacific Ocean| ]]
[[Category:Geography of Asia]]
[[Category:Geography of North America]]
[[Category:Geography of Oceania]]
[[Category:Oceans surrounding Antarctica]]
[[Category:Oceans]]
[[Category:Geography of South America]]