| 词条 | Adams Seamount |
| 释义 |
| name = Adams Seamount | depth = 39 m (128 ft)[1] | height = 3,500 m (11,500 ft) | map = | summit_area = | location=Pacific Ocean, SW of Pitcairn Island | group = | coordinates = {{coord|25|22|S|129|16|W|display=inline,title}} | country = | type = | volcanic_group = | age = | last_eruption= 50 BCE ± 1000 years | discovered = | discovered_by = | first_visit = | photo = }} Adams Seamount is a submarine volcano above the Pitcairn hotspot in the central Pacific Ocean about {{convert|100|km|mi|0}} southwest of Pitcairn Island. Geography and geomorphologyAdams is part of a field of about 90 seamounts {{convert|90|km}} east-southeast away from Pitcairn Island, and the largest of these.{{sfn|Garapić|Jackson|Hauri|Hart|2015|p=2}} Adams lies southeast of another large seamount, Bounty Seamount.{{sfn|Thießen|Schmidt|Botz|Schmitt|2004|p=418}} Most of these seamounts except for Adams and Bounty are less than {{convert|0.5|km}} high.{{sfn|Thießen|Schmidt|Botz|Schmitt|2004|p=409}} They were discovered in 1989 by the RV Sonne research ship.{{sfn|Hekinian|Cheminée|Dubois|Stoffers|2003|p=220}} It is a conical{{sfn|Binard|Hékinian|Stoffers|1992|p=261}} seamount rising {{convert|3500|m|ft|0}} from the sea floor to about {{convert|39|m|ft|0}} below the surface of the ocean.[1] The total volume of the seamount, whose "foot" has a diameter of about {{convert|30|km}}, is about {{convert|858|km3}}.{{sfn|Hekinian|Cheminée|Dubois|Stoffers|2003|p=228}} Adams has two summits,{{sfn|Binard|Hékinian|Stoffers|1992|p=257}} and coral and sand derived from coral has been found on Adams.{{sfn|Thießen|Schmidt|Botz|Schmitt|2004|p=409}} Given its height, during the last glacial maximum Adams was likely an island.[2] Its slopes are covered by recent lava flows, volcanic debris and hyaloclastite.{{sfn|Binard|Hékinian|Stoffers|1992|p=257}} Lava flows feature aa lava characteristics and lava tubes, while deeper parts of the edifice are covered with lapilli and scoria.{{sfn|Binard|Hékinian|Stoffers|1992|p=259}} Parasitic vents form cones and mounds on its flanks.{{sfn|Hekinian|Cheminée|Dubois|Stoffers|2003|p=229}} GeologyAdams and the other seamounts were created by the Pitcairn hotspot, and these seamounts are its present-day location.{{sfn|Garapić|Jackson|Hauri|Hart|2015|p=2}} This hotspot is one among several hotspots in the Pacific Ocean, along with the Austral hotspot, Hawaii hotspot, Louisville hotspot, Samoa hotspot and Society hotspot.{{sfn|Hekinian|Cheminée|Dubois|Stoffers|2003|p=220}} The seamounts rise from a 30 million years old crust.{{sfn|Guillou|Garcia|Turpin|1997|p=244}} Alkali basalt, trachyte{{sfn|Binard|Hékinian|Stoffers|1992|p=257}} and tholeiite have been dredged from Adams Seamount.{{sfn|Garapić|Jackson|Hauri|Hart|2015|p=9}} Eruption historyThe fresh appearance of samples and the lack of sedimentation indicates that Adams Seamount is a recently active seamount.{{sfn|Garapić|Jackson|Hauri|Hart|2015|p=2}} Potassium-argon dating of rocks dredged from Adams Seamount has yielded Holocene ages, including one age of 3,000 ± 1,000 years before present.{{sfn|Guillou|Garcia|Turpin|1997|p=244}} Other ages range from 4,000 - 7,000 years before present.{{sfn|Guillou|Garcia|Turpin|1997|p=247}} Unlike Bounty, Adams Seamount displays no active hydrothermal system.{{sfn|Thießen|Schmidt|Botz|Schmitt|2004|p=409}} References1. ^1 {{cite gvp|vn=333050 |name=Adams Seamount |accessdate=2017-02-28}} 2. ^{{cite journal|last1=Neall|first1=Vincent E.|last2=Trewick|first2=Steven A.|title=The age and origin of the Pacific islands: a geological overview|journal=Philosophical Transactions of the Royal Society of London B: Biological Sciences|date=27 October 2008|volume=363|issue=1508|pages=3293–3308|doi=10.1098/rstb.2008.0119|pmid=18768382|url=http://rstb.royalsocietypublishing.org/content/363/1508/3293.short|language=en|issn=0962-8436|pmc=2607379}} Sources{{refbegin}}
5 : Submarine volcanoes|Hotspot volcanoes|Seamounts of the Pacific Ocean|Landforms of the Pitcairn Islands|Former islands from the last glacial maximum |
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