View source for Plate tectonics

{{Short description|Movement of Earth's lithosphere}}
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[[File:Tectonic plates 2022.svg|thumb|300px|Map of Earth's [[list of tectonic plates|16 principal tectonic plates]]<br />
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[[Convergent boundary|Convergent]]:
{{legend-line|#8c6bb1 solid 2px|Collision zone}}
{{legend-line|#08519c solid 2px|Subduction zone}}
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[[Divergent boundary|Divergent]]:
{{legend-line|#e7298a solid 2px|Extension zone}}
{{legend-line|#a50f15 solid 2px|Spreading centre}}
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[[Transform fault|Transform]]:
{{legend-line|#fe9929 solid 2px|Dextral transform}}
{{legend-line|#006837 solid 2px|Sinistral transform}}
]]

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'''Plate tectonics''' ({{etymology|lat|{{Wikt-lang|la|tectonicus}}|}}, {{etymology|grc|''{{Wikt-lang|grc|τεκτονικός}}'' ({{grc-transl|τεκτονικός}})|pertaining to building}}){{sfn|Little|Fowler|Coulson|1990}} is the [[scientific theory]] that [[Earth]]'s [[lithosphere]] comprises a number of large [[list of tectonic plates|tectonic plates]], which have been slowly moving since 3–4 billion years ago.<ref name="Dhuime2012">{{Cite journal |last1=Dhuime |first1=B |last2=Hawkesworth |first2=CJ |last3=Cawood |first3=PA |last4=Storey |first4=CD |year=2012 |title=A change in the geodynamics of continental growth 3 billion years ago |journal=Science |volume=335 |issue=6074 |pages=1334–1336 |bibcode=2012Sci...335.1334D |doi=10.1126/science.1216066 |pmid=22422979 |s2cid=206538532}}</ref><ref name="Harrison2009">{{Cite journal |last=Harrison |first=TM |year=2009 |title=The Hadean crust: evidence from> 4 Ga zircons |journal=Annual Review of Earth and Planetary Sciences |volume=37 |issue=1 |pages=479–505 |bibcode=2009AREPS..37..479H |doi=10.1146/annurev.earth.031208.100151}}</ref><ref name="Windley2021">{{Cite journal |last1=Windley |first1=BF |last2=Kusky |first2=T |last3=Polat |first3=A |year=2021 |title=Onset of plate tectonics by the Eoarchean |journal=Precambrian Research |volume=352 |article-number=105980 |bibcode=2021PreR..35205980W |doi=10.1016/j.precamres.2020.105980 |s2cid=228993361}}</ref> The model builds on the concept of {{em|[[continental drift]]}}, an idea developed during the first decades of the 20th century. Plate tectonics came to be accepted by [[Earth science|geoscientists]] after [[seafloor spreading]] was validated in the mid- to late 1960s. The processes that result in plates and shape [[Earth's crust]] are called ''[[tectonics]]''.

Earth's lithosphere, the rigid outer shell of the planet including the [[crust (geology)|crust]] and [[upper mantle]], is fractured into [[List of tectonic plates#Major plates|seven or eight major plates]] (depending on how they are defined) and many minor plates or "platelets". Where the plates meet, their relative motion determines the [[list of tectonic plate interactions|type of plate boundary]] (or [[fault (geology)|fault]]): {{em|[[convergent boundary|convergent]]}}, {{em|[[divergent boundary|divergent]]}}, or {{em|[[transform fault|transform]]}}. The relative movement of the plates typically ranges from zero to 10 cm annually.{{sfn|Read|Watson|1975}} Faults tend to be geologically active, experiencing [[earthquake]]s, [[volcanism|volcanic activity]], [[mountain formation|mountain-building]], and [[oceanic trench]] formation.

Tectonic plates are composed of the oceanic lithosphere and the thicker continental lithosphere, each topped by its own kind of crust. Along [[convergent boundary|convergent plate boundaries]], the process of [[subduction]] carries the edge of one plate down under the other plate and into the [[mantle (geology)|mantle]]. This process reduces the total surface area (crust) of Earth. The lost surface is balanced by the formation of new [[oceanic crust]] along divergent margins by seafloor spreading, keeping the total [[geoid|surface area]] constant in a tectonic "conveyor belt".

While Earth is the only planet known to currently have active plate tectonics, evidence suggests that other planets and moons have experienced or exhibit forms of tectonic activity. For example, Jupiter's moon [[Europa (moon)|Europa]] shows signs of ice crustal plates moving and interacting, similar to Earth's plate tectonics.<ref>[https://www.nasa.gov/news-release/scientists-find-evidence-of-diving-tectonic-plates-on-jupiters-moon-europa/ Scientists Find Evidence of 'Diving' Tectonic Plates on Jupiter's Moon Europa]</ref> Additionally, Mars and Venus are thought to have had past tectonic activity, though not in the same form as Earth.<ref>[https://www.space.com/planets-exoplanets-plate-tectonics Do other planets have plate tectonics?]</ref>

Tectonic plates are relatively [[mechanical properties|rigid]] and float across the ductile [[asthenosphere]] beneath. Lateral density variations in the mantle result in [[mantle convection|convection]] currents, the slow creeping motion of Earth's solid mantle. At a [[mid-ocean ridge|seafloor spreading ridge]], plates move away from the ridge, which is a [[topography|topographic]] high, and the newly formed crust cools as it moves away, increasing its [[density]] and contributing to the motion. At a [[subduction]] zone, the relatively cold, dense oceanic crust sinks down into the mantle, forming the downward convecting limb of a [[Mantle convection|mantle cell]],<ref>{{Cite journal |last=Stern |first=Robert J. |year=2002 |title=Subduction zones |journal=[[Reviews of Geophysics]] |volume=40 |issue=4 |page=1012 |bibcode=2002RvGeo..40.1012S |doi=10.1029/2001RG000108 |s2cid=247695067 |doi-access=free}}</ref> which is the strongest driver of plate motion.<ref>{{Cite journal |last1=Forsyth |first1=D. |last2=Uyeda |first2=S. |year=1975 |title=On the Relative Importance of the Driving Forces of Plate Motion |journal=Geophysical Journal International |volume=43 |issue=1 |pages=163–200 |bibcode=1975GeoJ...43..163F |doi=10.1111/j.1365-246x.1975.tb00631.x |doi-access=free}}</ref>{{sfn|Conrad|Lithgow-Bertelloni|2002}} The relative importance and interaction of other proposed factors such as active convection, upwelling inside the mantle, and tidal drag of the Moon is still the subject of debate.

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== Key principles ==
{{More citations needed section|date=July 2021}}

The [[Structure of Earth|outer layers of Earth]] are divided into the [[lithosphere]] and [[asthenosphere]]. The division is based on differences in [[mechanical properties]] and in the method for [[heat transfer|the transfer of heat]]. The lithosphere is cooler and more rigid, while the asthenosphere is hotter and flows more easily. In terms of heat transfer, the lithosphere loses heat by [[heat conduction|conduction]], whereas the asthenosphere also transfers heat by [[convection]] and has a nearly [[Adiabatic process|adiabatic]] temperature gradient. This division should not be confused with the ''chemical'' subdivision of these same layers into the mantle (comprising both the asthenosphere and the mantle portion of the lithosphere) and the crust: a given piece of mantle may be part of the lithosphere or the asthenosphere at different times depending on its temperature and pressure.

The key principle of plate tectonics is that the lithosphere exists as separate and distinct [[list of tectonic plates|tectonic plates]], which ride on the [[Viscoelasticity|viscoelastic]] asthenosphere. Plate motions range from {{convert|10|to|40|mm/year|in/year|1}} at the [[Mid-Atlantic Ridge]] (about as fast as [[fingernail]]s grow), to about {{convert|160|mm/year|in/year}} for the [[Nazca plate]] (about as fast as [[hair]] grows).{{sfn|Zhen Shao|1997}}{{sfn|Hancock|Skinner|Dineley|2000}}

Tectonic lithospheric plates consist of lithospheric mantle overlain by one or two types of crustal material: [[oceanic crust]] (in older texts called ''[[sima (geology)|sima]]'' from [[silicon]] and [[magnesium]]) and [[continental crust]] (''[[sial]]'' from silicon and [[aluminium]]). The distinction between oceanic crust and continental crust is based on their modes of formation. Oceanic crust is formed at sea-floor spreading centers. Continental crust is formed through [[volcanic arc|arc volcanism]] and [[accretion (geology)|accretion]] of [[terrane]]s through plate tectonic processes. Oceanic crust is denser than continental crust because it has less silicon and more of the [[mafic|heavier elements]] than [[felsic|continental crust]].{{sfn|Schmidt|Harbert|1998}}<ref>{{Cite book |last=McGuire |first=Thomas |title=Earth Science: The Physical Setting |date=2005 |publisher=AMSCO School Publications Inc. |isbn=978-0-87720-196-0 |pages=182–184 |chapter=Earthquakes and Earth's Interior}}</ref> As a result of this density difference, oceanic crust generally lies below [[sea level]], while continental crust [[isostasy|buoyantly projects]] above sea level.

Average oceanic lithosphere is typically {{convert|100|km|0|abbr=on}} thick.{{sfn|Turcotte|Schubert|2002|p=5}} Its thickness is a function of its age. As time passes, it cools by conducting heat from below, and releasing it radiatively into space. The adjacent mantle below is cooled by this process and added to its base. Because it is formed at mid-ocean ridges and spreads outwards, its thickness is therefore a function of its distance from the mid-ocean ridge where it was formed. For a typical distance that oceanic lithosphere must travel before being subducted, the thickness varies from about {{convert|6|km|0|abbr=on}} thick at mid-ocean ridges to greater than {{convert|100|km|0|abbr=on}} at [[subduction]] zones. For shorter or longer distances, the subduction zone, and therefore also the mean, thickness becomes smaller or larger, respectively.{{sfn|Turcotte|Schubert|2002}} Continental lithosphere is typically about {{convert|200|km|abbr=on}} thick, though this varies considerably between basins, mountain ranges, and stable [[craton]]ic interiors of continents.

The location where two plates meet is called a ''plate boundary''. Plate boundaries are where geological events occur, such as [[earthquake]]s and the creation of topographic features such as [[mountain]]s, [[volcano]]es, [[mid-ocean ridge]]s, and [[oceanic trench]]es. The vast majority of the world's active volcanoes occur along plate boundaries, with the Pacific plate's [[Pacific Ring of Fire|Ring of Fire]] being the most active and widely known. Some volcanoes occur in the interiors of plates, and these have been variously attributed to internal plate deformation{{sfn|Foulger|2010}} and to mantle plumes.

Tectonic plates may include continental crust or oceanic crust, or both. For example, the [[African plate]] includes the continent and parts of the floor of the [[Atlantic Ocean|Atlantic]] and [[Indian Ocean|Indian]] Oceans.

Some pieces of oceanic crust, known as [[ophiolite]]s, failed to be subducted under continental crust at destructive plate boundaries; instead, these oceanic crustal fragments were pushed upward and were preserved within continental crust.

== Types of plate boundaries ==
{{Main|List of tectonic plate interactions}}

Three types of plate boundaries exist,{{sfn|Meissner|2002|p=100}} characterized by the way the plates move relative to each other. They are associated with different types of surface phenomena. The different types of plate boundaries are:<ref name="platetectonics.com">{{Cite web |title=Plate Tectonics: Plate Boundaries |url=http://www.platetectonics.com/book/page_5.asp |archive-url=https://web.archive.org/web/20100616062513/http://www.platetectonics.com/book/page_5.asp |archive-date=16 June 2010 |access-date=12 June 2010 |publisher=platetectonics.com}}</ref><ref name="usgs.understanding.com">{{Cite web |title=Understanding plate motions |url=https://pubs.usgs.gov/gip/dynamic/understanding.html |url-status=live |archive-url=https://web.archive.org/web/20190516204054/https://pubs.usgs.gov/gip/dynamic/understanding.html |archive-date=16 May 2019 |access-date=12 June 2010 |publisher=United States Geological Survey}}</ref>

[[File:Continental-continental constructive plate boundary.svg|thumb|upright=1.15|Divergent boundary]]
* ''[[Divergent boundary|Divergent boundaries]]'' (''constructive boundaries'' or ''extensional boundaries''). These are where two plates slide apart from each other. At zones of ocean-to-ocean rifting, divergent boundaries form by seafloor spreading, allowing for the formation of new [[oceanic basin|ocean basin]], e.g. the [[Mid-Atlantic Ridge]] and [[East Pacific Rise]]. As the ocean plate splits, the ridge forms at the spreading center, the ocean basin expands, and finally, the plate area increases causing many small volcanoes and/or shallow earthquakes. At zones of continent-to-continent rifting, divergent boundaries may cause new ocean basin to form as the continent splits, spreads, the central rift collapses, and ocean fills the basin, e.g., the [[East African Rift]], the [[Baikal Rift Zone|Baikal Rift]], the [[West Antarctic Rift]], the [[Rio Grande Rift]].

[[File:Continental-continental destructive plate boundary.svg|thumb|upright=1.15|Convergent boundary]]
* ''[[Convergent boundary|Convergent boundaries]]'' (''destructive boundaries'' or ''active margins'') occur where two plates slide toward each other to form either a [[subduction]] zone (one plate moving underneath the other) or a [[continental collision]]. 
:Subduction zones are of two types: ocean-to-continent subduction, where the dense oceanic lithosphere plunges beneath the less dense continent, or ocean-to-ocean subduction where older, cooler, denser oceanic crust slips beneath less dense oceanic crust. Deep marine trenches are typically associated with subduction zones, and the basins that develop along the active boundary are often called "foreland basins". 
:Earthquakes trace the path of the downward-moving plate as it descends into asthenosphere, a trench forms, and as the subducted plate is heated it releases volatiles, mostly water from [[serpentinite|hydrous minerals]], into the surrounding mantle. The addition of water lowers the melting point of the mantle material above the subducting slab, causing it to melt. The magma that results typically leads to volcanism.<ref name="H2O">{{Cite journal |last1=Grove |first1=Timothy L. |last2=Till |first2=Christy B. |last3=Krawczynski |first3=Michael J. |date=8 March 2012 |title=The Role of H2O in Subduction Zone Magmatism |url=https://www.researchgate.net/publication/235935490 |journal=[[Annual Review of Earth and Planetary Sciences]] |volume=40 |issue=1 |pages=413–39 |bibcode=2012AREPS..40..413G |doi=10.1146/annurev-earth-042711-105310 |access-date=14 January 2016}}</ref> 
:At zones of ocean-to-ocean subduction a deep trench forms in an arc shape. The upper mantle of the subducted plate then heats and magma rises to form curving chains of volcanic islands e.g. the [[Aleutian Islands]], the [[Mariana Islands]], the [[Japan]]ese [[island arc]]. 
:At zones of ocean-to-continent subduction mountain ranges form, e.g. the [[Andes]], the [[Cascade Range]].
:At continental collision zones there are two masses of continental lithosphere converging. Since they are of similar density, neither is subducted. The plate edges are compressed, folded, and uplifted forming mountain ranges, e.g. [[Himalayas]] and [[Alps]]. Closure of ocean basins can occur at continent-to-continent boundaries.

[[File:Continental-continental conservative plate boundary opposite directions.svg|thumb|upright=1.15|Transform boundary]]
* ''[[Transform fault|Transform boundaries]]'' (''conservative boundaries'' or '' strike-slip boundaries'') occur where plates are neither created nor destroyed. Instead, two plates slide, or perhaps more accurately grind past each other, along [[transform fault]]s.  The relative motion of the two plates is either [[sinistral and dextral|sinistral]] (left side toward the observer) or [[sinistral and dextral|dextral]] (right side toward the observer). Transform faults occur across a spreading center. Strong earthquakes can occur along a fault. The [[San Andreas Fault]] in California is an example of a transform boundary exhibiting dextral motion.
* Other ''plate boundary zones'' occur where the effects of the interactions are unclear, and the boundaries, usually occurring along a broad belt, are not well defined and may show various types of movements in different episodes.

== Driving forces of plate motion ==
[[File:Global plate motion 2008-04-17.jpg|thumb|upright=1.35|Plate motion based on [[Global Positioning System]] (GPS) satellite data from NASA [http://sideshow.jpl.nasa.gov/mbh/series.html JPL]. Each red dot is a measuring point and vectors show direction and magnitude of motion.]]

Tectonic plates are able to move because of the relative density of [[oceanic lithosphere]] and the relative weakness of the [[asthenosphere]]. [[Earth's internal heat budget|Dissipation of heat from the mantle]] is the original source of the energy required to drive plate tectonics through convection or large scale upwelling and doming. As a consequence, a powerful source generating plate motion is the excess density of the oceanic lithosphere sinking in subduction zones. When the new crust forms at mid-ocean ridges, this oceanic lithosphere is initially less dense than the underlying asthenosphere, but it becomes denser with age as it conductively cools and thickens. The greater [[density]] of old lithosphere relative to the underlying asthenosphere allows it to sink into the deep mantle at subduction zones, providing most of the driving force for plate movement. The weakness of the asthenosphere allows the tectonic plates to move easily towards a subduction zone.<ref>{{Cite web |last=Mendia-Landa |first=Pedro |title=Myths and Legends on Natural Disasters: Making Sense of Our World |url=http://www.yale.edu/ynhti/curriculum/units/2007/4/07.04.13.x.html |url-status=live |archive-url=https://web.archive.org/web/20160721160510/http://www.yale.edu/ynhti/curriculum/units/2007/4/07.04.13.x.html |archive-date=2016-07-21 |access-date=2008-02-05}}</ref>

=== Driving forces related to mantle dynamics ===
{{Main|Mantle convection}}
For much of the first quarter of the 20th century, the leading theory of the driving force behind tectonic plate motions envisaged large scale convection currents in the upper mantle, which can be transmitted through the asthenosphere. This theory was launched by [[Arthur Holmes]] and some forerunners in the 1930s<ref>{{Cite journal |last=Holmes |first=Arthur |author-link=Arthur Holmes |year=1931 |title=Radioactivity and Earth Movements |url=http://www.mantleplumes.org/WebDocuments/Holmes1931.pdf |url-status=live |journal=[[Transactions of the Geological Society of Glasgow]] |volume=18 |issue=3 |pages=559–606 |doi=10.1144/transglas.18.3.559 |s2cid=122872384 |archive-url=https://web.archive.org/web/20191009101823/http://www.mantleplumes.org/WebDocuments/Holmes1931.pdf |archive-date=2019-10-09 |access-date=2014-01-15}}</ref> and was immediately recognized as the solution for the acceptance of the theory as originally discussed in the papers of [[Alfred Wegener]] in the early years of the 20th century. However, despite its acceptance, it was long debated in the scientific community because the leading theory still envisaged a static Earth without moving continents up until the major breakthroughs of the early sixties.

Two- and three-dimensional imaging of Earth's interior ([[seismic tomography]]) shows a varying lateral density distribution throughout the mantle. Such density variations can be material (from rock chemistry), mineral (from variations in mineral structures), or thermal (through thermal expansion and contraction from heat energy). The manifestation of this varying lateral density is [[mantle convection]] from buoyancy forces.{{sfn|Tanimoto|Lay|2000}}

How mantle convection directly and indirectly relates to plate motion is a matter of ongoing study and discussion in [[geodynamics]]. Somehow, this [[energy]] must be transferred to the lithosphere for tectonic plates to move. There are essentially two main types of mechanisms that are thought to exist related to the dynamics of the mantle that influence plate motion which are primary (through the large scale convection cells) or secondary. The secondary mechanisms view plate motion driven by friction between the convection currents in the asthenosphere and the more rigid overlying lithosphere. This is due to the inflow of mantle material related to the downward pull on plates in subduction zones at ocean trenches. Slab pull may occur in a geodynamic setting where basal tractions continue to act on the plate as it dives into the mantle (although perhaps to a greater extent acting on both the under and upper side of the slab). Furthermore, slabs that are broken off and sink into the mantle can cause viscous mantle forces driving plates through slab suction.

==== Plume tectonics ====
In the theory of [[plume tectonics]] followed by numerous researchers during the 1990s, a modified concept of mantle convection currents is used. It asserts that super plumes rise from the deeper mantle and are the drivers or substitutes of the major convection cells. These ideas find their roots in the early 1930s in the works of [[Vladimir Belousov|Beloussov]] and [[Reinout Willem van Bemmelen|van Bemmelen]], which were initially opposed to plate tectonics and placed the mechanism in a fixed frame of vertical movements. Van Bemmelen later modified the concept in his "Undation Models" and used "Mantle Blisters" as the driving force for horizontal movements, invoking gravitational forces away from the regional crustal doming.{{sfn|Van Bemmelen|1976}}{{sfn|Van Bemmelen|1972}}

The theories find resonance in the modern theories which envisage [[hotspot (geology)|hot spots]] or [[mantle plumes]] which remain fixed and are overridden by oceanic and continental lithosphere plates over time and leave their traces in the geological record (though these phenomena are not invoked as real driving mechanisms, but rather as modulators).

The mechanism is still advocated to explain the break-up of supercontinents during specific geological epochs.{{sfn|Segev|2002}} It has followers amongst the scientists involved in the [[Expanding Earth|theory of Earth expansion]].{{sfn|Maruyama|1994}}{{sfn|Yuen|Maruyama|Karato|Windley|2007}}{{sfn|Wezel|1988}}

==== Surge tectonics ====
Another theory is that the mantle flows neither in cells nor large plumes but rather as a series of channels just below Earth's crust, which then provide basal friction to the lithosphere. This theory, called "surge tectonics", was popularized during the 1980s and 1990s.{{sfn|Meyerhoff|Taner|Morris|Agocs|1996}} Recent research, based on three-dimensional computer modelling, suggests that plate geometry is governed by a feedback between mantle convection patterns and the strength of the lithosphere.{{sfn|Mallard|Coltice|Seton|Müller|2016}}

=== Driving forces related to gravity ===
Forces related to gravity are invoked as secondary phenomena within the framework of a more general driving mechanism such as the various forms of mantle dynamics described above. In modern views, gravity is invoked as the major driving force, through slab pull along subduction zones.

Gravitational sliding away from a spreading ridge is one of the proposed driving forces: plate motion is driven by the higher elevation of plates at ocean ridges.{{sfn|Spence|1987}}{{sfn|White|McKenzie|1989}} As oceanic lithosphere is formed at spreading ridges from hot mantle material, it gradually cools and thickens with age (and thus adds distance from the ridge). Cool oceanic lithosphere is significantly denser than the hot mantle material from which it is derived and so with increasing thickness it gradually subsides into the mantle to compensate the greater load. The result is a slight lateral incline with increased distance from the ridge axis.

This force is regarded as a secondary force and is often referred to as "[[ridge push force|ridge push]]". This is a misnomer as there is no force "pushing" horizontally, indeed tensional features are dominant along ridges. It is more accurate to refer to this mechanism as "gravitational sliding", since the topography across the whole plate can vary considerably and spreading ridges are only the most prominent feature. Other mechanisms generating this gravitational secondary force include [[Lithospheric flexure|flexural bulging]] of the lithosphere before it dives underneath an adjacent plate, producing a clear topographical feature that can offset, or at least affect, the influence of topographical ocean ridges. [[Mantle plume]]s and hot spots are also postulated to impinge on the underside of tectonic plates.

[[Slab pull]]: Scientific opinion is that the asthenosphere is insufficiently competent or rigid to directly cause motion by friction along the base of the lithosphere. Slab pull is therefore most widely thought to be the greatest force acting on the plates. In this understanding, plate motion is mostly driven by the weight of cold, dense plates sinking into the mantle at trenches.{{sfn|Conrad|Lithgow-Bertelloni|2002}} Recent models indicate that [[back-arc basin|trench suction]] plays an important role as well. However, the fact that the [[North American plate]] is nowhere being subducted, although it is in motion, presents a problem. The same holds for the African, [[Eurasian plate|Eurasian]], and [[Antarctic plate|Antarctic]] plates.

Gravitational sliding away from mantle doming: According to older theories, one of the driving mechanisms of the plates is the existence of large scale asthenosphere/mantle domes which cause the gravitational sliding of lithosphere plates away from them (see the paragraph on Mantle Mechanisms). This gravitational sliding represents a secondary phenomenon of this basically vertically oriented mechanism. It finds its roots in the Undation Model of [[Reinout Willem van Bemmelen|van Bemmelen]]. This can act on various scales, from the small scale of one island arc up to the larger scale of an entire ocean basin.{{sfn|Spence|1987}}{{sfn|White|McKenzie|1989}}{{sfn|Segev|2002}}

=== Driving forces related to Earth rotation ===
[[Alfred Wegener]], being a [[meteorologist]], had proposed [[tidal force]]s and [[centrifugal force]]s as the main driving mechanisms behind [[continental drift]]; however, these forces were considered far too small to cause continental motion as the concept was of continents plowing through oceanic crust.<ref>{{Cite web |title=Alfred Wegener (1880–1930) |url=http://www.ucmp.berkeley.edu/history/wegener.html |archive-url=https://web.archive.org/web/20171208011353/http://www.ucmp.berkeley.edu/history/wegener.html |archive-date=2017-12-08 |access-date=2010-06-18 |publisher=[[University of California Museum of Paleontology]]}}</ref> Therefore, Wegener later changed his position and asserted that convection currents are the main driving force of plate tectonics in the last edition of his book in 1929.

However, in the plate tectonics context (accepted since the [[seafloor spreading]] proposals of Heezen, Hess, Dietz, Morley, Vine, and Matthews (see below) during the early 1960s), the oceanic crust is suggested to be in motion ''with'' the continents, which caused the proposals related to Earth rotation to be reconsidered. In more recent literature, these driving forces are:
# Tidal drag due to the gravitational force the [[Moon]] (and the [[Sun]]) exerts on the crust of Earth.<ref>{{Cite web |last=Neith, Katie |date=April 15, 2011 |title=Caltech Researchers Use GPS Data to Model Effects of Tidal Loads on Earth's Surface |url=http://media.caltech.edu/press_releases/13411 |archive-url=https://web.archive.org/web/20111019023322/http://media.caltech.edu/press_releases/13411 |archive-date=October 19, 2011 |access-date=August 15, 2012 |publisher=[[California Institute of Technology|Caltech]]}}</ref>
# Global deformation of the [[geoid]] due to small displacements of the rotational pole with respect to Earth's crust.
# Other smaller deformation effects of the crust due to wobbles and spin movements of Earth's rotation on a smaller timescale.

Forces that are small and generally negligible are:

# The [[Coriolis force]].<ref name="Ricard">{{Cite encyclopedia |year=2009 |title=Treatise on Geophysics: Mantle Dynamics |publisher=Elsevier Science |last=Ricard |first=Y. |editor-last=Bercovici |editor-first=David |volume=7 |page=36 |isbn=978-0-444-53580-1 |chapter=2. Physics of Mantle Convection |editor2-last=Schubert |editor2-first=Gerald |chapter-url=https://books.google.com/books?id=bIHNCgAAQBAJ}}</ref><ref name="Glatzmaier2013">{{Cite book |last=Glatzmaier |first=Gary A. |url=https://books.google.com/books?id=RY-GAAAAQBAJ&pg=PR4 |title=Introduction to Modeling Convection in Planets and Stars: Magnetic Field, Density Stratification, Rotation |publisher=[[Princeton University Press]] |year=2013 |isbn=978-1-4008-4890-4 |page=149}}</ref>
# The [[centrifugal force]], which is treated as a slight modification of gravity.<ref name=Ricard/><ref name=Glatzmaier2013/>{{rp|249}}

For these mechanisms to be overall valid, systematic relationships should exist all over the globe between the orientation and kinematics of deformation and the geographical [[latitude|latitudinal]] and [[longitude|longitudinal]] grid of Earth itself. Systematic relations studies in the second half of the nineteenth century and the first half of the twentieth century underlined exactly the opposite: that the plates had not moved in time, that the deformation grid was fixed with respect to Earth's [[equator]] and axis, and that gravitational driving forces were generally acting vertically and caused only local horizontal movements (the so-called pre-plate tectonic, "fixist theories"). Later studies (discussed below on this page), therefore, invoked many of the relationships recognized during this pre-plate tectonics period to support their theories (see reviews of these various mechanisms related to Earth rotation in the work of van Dijk and collaborators).<ref>{{harvnb|van Dijk|1992}}, {{harvnb|van Dijk|Okkes|1990}}.</ref>

==== Possible tidal effect on plate tectonics{{anchor|Tidal effect}} ====
{{see also|Tidal triggering of earthquakes}}

Of the many forces discussed above, tidal force is still highly debated and defended as a possible principal driving force of plate tectonics. The other forces are only used in global geodynamic models not using plate tectonics concepts (therefore beyond the discussions treated in this section) or proposed as minor modulations within the overall plate tectonics model.
In 1973, George W. Moore{{sfn|Moore|1973}} of the [[United States Geological Survey|USGS]] and R. C. Bostrom{{sfn|Bostrom|1971}} presented evidence for a general westward drift of Earth's lithosphere with respect to the mantle, based on the steepness of the subduction zones (shallow dipping towards the east, steeply dipping towards the west). They concluded that tidal forces (the tidal lag or "friction") caused by Earth's rotation and the forces acting upon it by the Moon are a driving force for plate tectonics. As Earth spins eastward beneath the Moon, the Moon's gravity ever so slightly pulls Earth's surface layer back westward, just as proposed by Alfred Wegener (see above). Since 1990 this theory has been mainly advocated by Doglioni and co-workers {{Harv|Doglioni|1990}}, such as in a more recent 2006 study,{{sfn|Scoppola|Boccaletti|Bevis|Carminati|2006}} where scientists reviewed and advocated these ideas. It has been suggested in {{Harvtxt|Lovett|2006}} that this observation may also explain why [[Venus]] and [[Mars]] have no plate tectonics, as Venus has no moon and Mars' moons are too small to have significant tidal effects on the planet. In a paper by Torsvik et al.,{{sfn|Torsvik|Steinberger|Gurnis|Gaina|2010}} it was suggested that, on the other hand, it can easily be observed that many plates are moving north and eastward, and that the dominantly westward motion of the Pacific Ocean basins derives simply from the eastward bias of the Pacific spreading center (which is not a predicted manifestation of such lunar forces). In the same paper the authors admit, however, that relative to the lower mantle, there is a slight westward component in the motions of all the plates. They demonstrated though that the westward drift, seen only for the past 30&nbsp;Ma, is attributed to the increased dominance of the steadily growing and accelerating Pacific plate. The debate is still open, and a 2022 paper by Hofmeister et al.{{Sfn|Hofmeister|Criss|Criss|2022}} revived the idea of the interaction between Earth's rotation and the Moon as the main driving force for plate movement.

===Role of water===
{{Expand section|date=October 2025}}
The role of water has been proposed to be crucial in plate tectonics on Earth.<ref>{{cite journal | url=https://ui.adsabs.harvard.edu/abs/2001AGUFM.U21A..09S/abstract | bibcode=2001AGUFM.U21A..09S | title=The role of liquid water in maintaining plate tectonics and the regulation of surface temperature | last1=Solomatov | first1=V. S. | journal=AGU Fall Meeting Abstracts | date=2001 | volume=2001 }}</ref><ref>{{cite journal | pmc=5394257 | date=2017 | last1=Tikoo | first1=S. M. | last2=Elkins-Tanton | first2=L. T. | title=The fate of water within Earth and super-Earths and implications for plate tectonics | journal=Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences | volume=375 | issue=2094 | doi=10.1098/rsta.2015.0394 | pmid=28416729 | bibcode=2017RSPTA.37550394T }}</ref><ref>{{cite web |url=https://phys.org/news/2013-06-lubricant-reassessment-role-plate-tectonics.html |title=Water is no lubricant: Reassessment of the role of water in plate tectonics |author=Helmholtz Association of German Research Centres |website=Phys.org |date=12 June 2013 |access-date=13 January 2025}}</ref>

=== Relative significance of each driving force mechanism ===
The [[Euclidean vector|vector]] of a plate's motion is a function of all the forces acting on the plate; however, therein lies the problem regarding the degree to which each process contributes to the overall motion of each tectonic plate.

The diversity of geodynamic settings and the properties of each plate result from the impact of the various processes actively driving each individual plate. One method of dealing with this problem is to consider the relative rate at which each plate is moving as well as the evidence related to the significance of each process to the overall driving force on the plate.

One of the most significant correlations discovered to date is that lithospheric plates attached to downgoing (subducting) plates move much faster than other types of plates. The Pacific plate, for instance, is essentially surrounded by zones of subduction (the so-called Ring of Fire) and moves much faster than the plates of the Atlantic basin, which are attached (perhaps one could say 'welded') to adjacent continents instead of subducting plates. It is thus thought  that forces associated with the downgoing plate (slab pull and slab suction) are the driving forces which determine the motion of plates, except for those plates which are not being subducted.{{sfn|Conrad|Lithgow-Bertelloni|2002}} This view however has been contradicted by a recent study which found that the actual motions of the Pacific plate and other plates associated with the East Pacific Rise do not correlate mainly with either slab pull or slab push, but rather with a mantle convection upwelling whose horizontal spreading along the bases of the various plates drives them along via viscosity-related traction forces.<ref name="Rowley-etal_2016">{{Cite journal |last1=Rowley |first1=David B. |last2=Forte |first2=Alessandro M. |last3=Rowan |first3=Christopher J. |last4=Glišović |first4=Petar |last5=Moucha |first5=Robert |last6=Grand |first6=Stephen P. |last7=Simmons |first7=Nathan A. |year=2016 |title=Kinematics and dynamics of the East Pacific Rise linked to a stable, deep-mantle upwelling |journal=[[Science Advances]] |volume=2 |issue=12 |article-number=e1601107 |bibcode=2016SciA....2E1107R |doi=10.1126/sciadv.1601107 |pmc=5182052 |pmid=28028535}}</ref> The driving forces of plate motion continue to be active subjects of on-going research within [[geophysics]] and [[tectonophysics]].

== History of the theory ==
{{Further|Plate Tectonics Revolution}}

=== Summary ===
[[File:Tectonic plates boundaries physical World map Wt 180degE centered-en.svg|thumb|upright=1.35|right|Detailed map showing the tectonic plates with their movement vectors]]
The development of the theory of plate tectonics was the scientific and cultural change which occurred during a period of 50 years of scientific debate. The event of the acceptance itself was a [[paradigm shift]] and can therefore be classified as a scientific revolution,<ref>{{Cite journal |last1=Casadevall |first1=Arturo |last2=Fang |first2=Ferric C. |date=1 March 2016 |title=Revolutionary Science |journal=[[mBio]] |volume=7 |issue=2 |pages=e00158–16 |doi=10.1128/mBio.00158-16 |pmc=4810483 |pmid=26933052}}</ref> now described as the [[Plate Tectonics Revolution]].

Around the start of the twentieth century, various theorists unsuccessfully attempted to explain the many geographical, geological, and biological continuities between continents. In 1912, the meteorologist [[Alfred Wegener]] described what he called continental drift, an idea that culminated fifty years later in the modern theory of plate tectonics.<ref>{{Cite web |last=Hughes |first=Patrick |date=8 February 2001 |title=Alfred Wegener (1880–1930): A Geographic Jigsaw Puzzle |url=http://earthobservatory.nasa.gov/Features/Wegener/wegener_2.php |access-date=2007-12-26 |website=On the Shoulders of Giants |publisher=Earth Observatory, [[NASA]] |quote=... on January 6, 1912, Wegener... proposed instead a grand vision of drifting continents and widening seas to explain the evolution of Earth's geography.}}</ref>

Wegener expanded his theory in his 1915 book ''The Origin of Continents and Oceans''.{{sfn|Wegener|1929}} Starting from the idea (also expressed by his forerunners) that the present continents once formed a single land mass (later called [[Pangaea]]), Wegener suggested that these separated and drifted apart, likening them to "icebergs" of low density [[sial]] floating on a sea of denser [[Sima (geology)|sima]].<ref>{{Cite web |last=Hughes |first=Patrick |date=8 February 2001 |title=Alfred Wegener (1880–1930): The origin of continents and oceans |url=http://earthobservatory.nasa.gov/Features/Wegener/wegener_4.php |access-date=2007-12-26 |website=On the Shoulders of Giants |publisher=Earth Observatory, [[NASA]] |quote=By his third edition (1922), Wegener was citing geological evidence that some 300{{nbsp}}million years ago all the continents had been joined in a supercontinent stretching from pole to pole. He called it Pangaea (all lands),...}}</ref>{{sfn|Wegener|1966}} Supporting evidence for the idea came from the dove-tailing outlines of South America's east coast and Africa's west coast [[Antonio Snider-Pellegrini]] had drawn on his maps, and from the matching of the rock formations along these edges. Confirmation of their previous contiguous nature also came from the fossil plants ''[[Glossopteris]]'' and ''[[Gangamopteris]]'', and the [[therapsid]] or [[mammal-like reptile]] ''[[Lystrosaurus]]'', all widely distributed over South America, Africa, Antarctica, India, and Australia. The evidence for such an erstwhile joining of these continents was patent to field geologists working in the southern hemisphere. The South African [[Alex du Toit]] put together a mass of such information in his 1937 publication ''Our Wandering Continents'', and went further than Wegener in recognising the strong links between the [[Gondwana]] fragments.

Wegener's work was initially not widely accepted, in part due to a lack of detailed evidence but mostly because of the lack of a reasonable physically supported mechanism. Earth might have a solid crust and mantle and a liquid core, but there seemed to be no way that portions of the crust could move around. Many distinguished scientists of the time, such as [[Harold Jeffreys]] and [[Charles Schuchert]], were outspoken critics of continental drift.

Despite much opposition, the view of continental drift gained support and a lively debate started between "drifters" or "mobilists" (proponents of the theory) and "fixists" (opponents). During the 1920s, 1930s and 1940s, the former reached important milestones proposing that [[convection current]]s might have driven the plate movements, and that spreading may have occurred below the sea within the oceanic crust. Concepts close to the elements of plate tectonics were proposed by geophysicists and geologists (both fixists and mobilists) like Vening-Meinesz, Holmes, and Umbgrove. In 1941, [[Otto Ampferer]] described, in his publication "Thoughts on the motion picture of the Atlantic region",<ref>[[Otto Ampferer]]: ''[https://www.zobodat.at/pdf/SBAWW_150_0019-0035.pdf Thoughts on the motion picture of the Atlantic region].'' Sber. österr. Akad. Wiss., math.-naturwiss. KL, 150, 19–35, 6 figs., Vienna 1941.</ref> processes that anticipated [[seafloor spreading]] and [[subduction]].<ref>{{Cite journal |last1=Dullo |first1=Wolf-Christian |last2=Pfaffl |first2=Fritz A. |date=28 March 2019 |title=The theory of undercurrent from the Austrian alpine geologist Otto Ampferer (1875–1947): first conceptual ideas on the way to plate tectonics |url=https://cdnsciencepub.com/doi/full/10.1139/cjes-2018-0157 |journal=[[Canadian Journal of Earth Sciences]] |volume=56 |issue=11 |pages=1095–1100 |bibcode=2019CaJES..56.1095D |doi=10.1139/cjes-2018-0157 |s2cid=135079657|url-access=subscription }}</ref><ref>Karl Krainer, Christoph Hauser: ''[https://www2.uibk.ac.at/downloads/c715/geoalp_sbd1_07/krainer_hauser.pdf Otto Ampferer (1875-1947): pioneer in geology, mountaineer, collector and draughtsman]''. In: Geo. Alp Sonderband 1, 2007, pp. 94–95.</ref> One of the first pieces of geophysical evidence that was used to support the movement of lithospheric plates came from [[paleomagnetism]]. This is based on the fact that rocks of different ages show a variable [[magnetic field]] direction, evidenced by studies since the mid–nineteenth century. The magnetic north and south poles reverse through time, and, especially important in paleotectonic studies, the relative position of the magnetic north pole varies through time. Initially, during the first half of the twentieth century, the latter phenomenon was explained by introducing what was called "polar wander" (see [[apparent polar wander]]) (i.e., it was assumed that the north pole location had been shifting through time). An alternative explanation, though, was that the continents had moved (shifted and rotated) relative to the north pole, and each continent, in fact, shows its own "polar wander path". During the late 1950s, it was successfully shown on two occasions that these data could show the validity of continental drift: by Keith Runcorn in a paper in 1956,{{sfn|Runcorn|1956}} and by Warren Carey in a symposium held in March 1956.{{sfn|Carey|1958}}

The second piece of evidence in support of continental drift came during the late 1950s and early 60s from data on the bathymetry of the deep [[ocean floor]]s and the nature of the oceanic crust such as magnetic properties and, more generally, with the development of [[marine geology]]<ref>see for example the milestone paper of {{Harvnb|Lyman|Fleming|1940}}.</ref> which gave evidence for the association of seafloor spreading along the [[mid-oceanic ridge]]s and [[Geomagnetic reversal|magnetic field reversals]], published between 1959 and 1963 by Heezen, Dietz, Hess, Mason, Vine & Matthews, and Morley.<ref>{{Harvnb|Korgen|1995}}, {{Harvnb|Spiess|Kuperman|2003}}.</ref>

Simultaneous advances in early [[seismic]] imaging techniques in and around [[Wadati–Benioff zone]]s along the trenches bounding many continental margins, together with many other geophysical (e.g., gravimetric) and geological observations, showed how the oceanic crust could disappear into the mantle, providing the mechanism to balance the extension of the ocean basins with shortening along its margins.

All this evidence, both from the ocean floor and from the continental margins, made it clear around 1965 that continental drift was feasible. The theory of plate tectonics was defined in a series of papers between 1965 and 1967. The theory revolutionized the Earth sciences, explaining a diverse range of geological phenomena and their implications in other studies such as [[paleogeography]] and [[paleobiology]].

=== Continental drift ===
{{Further|Continental drift}}
In the late 19th and early 20th centuries, geologists assumed that Earth's major features were fixed, and that most geologic features such as basin development and mountain ranges could be explained by vertical crustal movement, described in what is called the [[geosyncline|geosynclinal theory]]. Generally, this was placed in the context of a contracting planet Earth due to heat loss in the course of a relatively short geological time.
[[File:Wegener Expedition-1912 008.jpg|thumb|Alfred Wegener in Greenland in the winter of 1912–13]]
It was observed as early as 1596 that the opposite [[coasts]] of the Atlantic Ocean—or, more precisely, the edges of the [[continental shelves]]—have similar shapes and seem to have once fitted together.{{sfn|Kious|Tilling|1996}}

Since that time many theories were proposed to explain this apparent complementarity, but the assumption of a solid Earth made these various proposals difficult to accept.{{sfn|Frankel|1987}}

The discovery of [[radioactivity]] and its associated [[exothermic|heating]] properties in 1895 prompted a re-examination of the apparent [[age of Earth]].{{sfn|Joly|1909}} This had previously been estimated by its cooling rate under the assumption that Earth's surface radiated like a [[black body]].{{sfn|Thomson|1863}} Those calculations had implied that, even if it started at [[thermal radiation|red heat]], Earth would have dropped to its present temperature in a few tens of millions of years. Armed with the knowledge of a new heat source, scientists realized that Earth would be much older, and that [[Earth's core|its core]] was still sufficiently hot to be liquid.

By 1915, after having published a first article in 1912,{{sfn|Wegener|1912}} Alfred Wegener was making serious arguments for the idea of continental drift in the first edition of ''The Origin of Continents and Oceans''.{{sfn|Wegener|1929}} In that book (re-issued in four successive editions up to the final one in 1936), he noted how the east coast of [[South America]] and the west coast of [[Africa]] looked as if they were once attached. Wegener was not the first to note this ([[Abraham Ortelius]], [[Antonio Snider-Pellegrini]], [[Eduard Suess]], [[Roberto Mantovani]] and [[Frank Bursley Taylor]] preceded him just to mention a few), but he was the first to marshal significant [[fossil]] and paleo-topographical and climatological evidence to support this simple observation (and was supported in this by researchers such as [[Alex du Toit]]). Furthermore, when the rock [[stratum|strata]] of the margins of separate continents are very similar it suggests that these rocks were formed in the same way, implying that they were joined initially. For instance, parts of [[Scotland]] and [[Ireland]] contain rocks very similar to those found in [[Newfoundland and Labrador|Newfoundland]] and [[New Brunswick]]. Furthermore, the [[Caledonian Mountains]] of Europe and parts of the [[Appalachian Mountains]] of North America are very similar in [[Structural geology|structure]] and [[lithology]].

However, his ideas were not taken seriously by many geologists, who pointed out that there was no apparent mechanism for continental drift. Specifically, they did not see how continental rock could plow through the much denser rock that makes up oceanic crust. Wegener could not explain the force that drove continental drift, and his vindication did not come until after his death in 1930.<ref>{{Cite web |title=Pioneers of Plate Tectonics |url=https://www.geolsoc.org.uk/Plate-Tectonics/Chap1-Pioneers-of-Plate-Tectonics/Alfred-Wegener |url-status=live |archive-url=https://web.archive.org/web/20180323155937/https://www.geolsoc.org.uk/Plate-Tectonics/Chap1-Pioneers-of-Plate-Tectonics/Alfred-Wegener |archive-date=23 March 2018 |access-date=23 March 2018 |website=[[The Geological Society]]}}</ref>

=== Floating continents, paleomagnetism, and seismicity zones ===
[[File:Quake epicenters 1963-98.png|thumb|upright=1.35|Global earthquake [[epicenter]]s, 1963–1998. Most earthquakes occur in narrow belts that correspond to the locations of lithospheric plate boundaries.]]
[[File:Map of earthquakes in 2016.svg|thumb|upright=1.35|right|Map of earthquakes in 2016]]

As it was observed early that although [[granite]] existed on continents, seafloor seemed to be composed of denser [[basalt]], the prevailing concept during the first half of the twentieth century was that there were two types of crust, named "sial" (continental type crust) and "sima" (oceanic type crust). Furthermore, it was supposed that a static shell of strata was present under the continents. It therefore looked apparent that a layer of basalt (sial) underlies the continental rocks.

However, based on abnormalities in [[plumb line deflection]] by the [[Andes]] in Peru, [[Pierre Bouguer]] had deduced that less-dense mountains must have a downward projection into the denser layer underneath. The concept that mountains had "roots" was confirmed by [[George B. Airy]] a hundred years later, during study of [[Himalaya]]n gravitation, and seismic studies detected corresponding density variations. Therefore, by the mid-1950s, the question remained unresolved as to whether mountain roots were clenched in surrounding basalt or were floating on it like an iceberg.

During the 20th century, improvements in and greater use of seismic instruments such as [[seismograph]]s enabled scientists to learn that earthquakes tend to be concentrated in specific areas, most notably along the [[oceanic trenches]] and spreading ridges. By the late 1920s, seismologists were beginning to identify several prominent earthquake zones parallel to the trenches that typically were inclined 40–60° from the horizontal and extended several hundred kilometers into Earth. These zones later became known as Wadati–Benioff zones, or simply Benioff zones, in honor of the seismologists who first recognized them, [[Kiyoo Wadati]] of Japan and [[Hugo Benioff]] of the United States. The study of global seismicity greatly advanced in the 1960s with the establishment of the Worldwide Standardized Seismograph Network (WWSSN){{sfn|Stein|Wysession|2009|p=26}} to monitor the compliance of the 1963 treaty banning above-ground testing of nuclear weapons. The much improved data from the WWSSN instruments allowed seismologists to map precisely the zones of earthquake concentration worldwide.

Meanwhile, debates developed around the phenomenon of polar wander. Since the early debates of continental drift, scientists had discussed and used evidence that polar drift had occurred because continents seemed to have moved through different climatic zones during the past. Furthermore, paleomagnetic data had shown that the magnetic pole had also shifted during time. Reasoning in an opposite way, the continents might have shifted and rotated, while the pole remained relatively fixed. The first time the evidence of magnetic polar wander was used to support the movements of continents was in a paper by [[Keith Runcorn]] in 1956,{{sfn|Runcorn|1956}} and successive papers by him and his students [[Ted Irving]] (who was actually the first to be convinced of the fact that paleomagnetism supported continental drift) and Ken Creer.

This was immediately followed by a symposium on continental drift in [[Tasmania]] in March 1956 organised by [[Samuel Warren Carey|S. Warren Carey]] who had been one of the supporters and promotors of Continental Drift since the thirties<ref>{{Harvnb|Carey|1958}}; see also {{Harvnb|Quilty|Banks|2003}}.</ref> During this symposium, some of the participants used the evidence in the theory of an [[expanding Earth|expansion of the global crust]], a theory which had been proposed by other workers decades earlier. In this hypothesis, the shifting of the continents is explained by a large increase in the size of Earth since its formation. However, although the theory still has supporters in science, this is generally regarded as unsatisfactory because there is no convincing mechanism to produce a significant expansion of Earth. Other work during the following years would soon show that the evidence was equally in support of continental drift on a globe with a stable radius.

During the 1930s up to the late 1950s, works by [[Felix Andries Vening Meinesz|Vening-Meinesz]], Holmes, [[Johannes Herman Frederik Umbgrove|Umbgrove]], and numerous others outlined concepts that were close or nearly identical to modern plate tectonics theory. In particular, the English geologist [[Arthur Holmes]] proposed in 1920 that plate junctions might lie beneath the [[sea]], and in 1928 that convection currents within the mantle might be the driving force.<ref>{{Harvnb|Holmes|1928}}; see also {{Harvnb|Holmes|1978}}, {{Harvnb|Frankel|1978}}.</ref> Often, these contributions are forgotten because:
* At the time, continental drift was not accepted.
* Some of these ideas were discussed in the context of abandoned fixist ideas of a deforming globe without continental drift or an expanding Earth.
* They were published during an episode of extreme political and economic instability that hampered scientific communication.
* Many were published by European scientists and at first not mentioned or given little credit in the papers on sea floor spreading published by the American researchers in the 1960s.

=== Mid-oceanic ridge spreading and convection ===
{{Further|topic=Mid-ocean ridge|Seafloor spreading}}

In 1947, a team of scientists led by [[Maurice Ewing]] utilizing the [[Woods Hole Oceanographic Institution]]'s research vessel ''Atlantis'' and an array of instruments, confirmed the existence of a rise in the central Atlantic Ocean, and found that the floor of the seabed beneath the layer of sediments consisted of basalt, not the granite which is the main constituent of continents. They also found that the oceanic crust was much thinner than continental crust. All these new findings raised important and intriguing questions.<ref>{{Harvnb|Lippsett|2001}}, {{Harvnb|Lippsett|2006}}.</ref>

The new data that had been collected on the ocean basins also showed particular characteristics regarding the bathymetry. One of the major outcomes of these datasets was that all along the globe, a system of mid-oceanic ridges was detected. An important conclusion was that along this system, new ocean floor was being created, which led to the concept of the "[[Great Global Rift]]". This was described in the crucial paper of [[Bruce C. Heezen|Bruce Heezen]] (1960) based on his work with [[Marie Tharp]],{{sfn|Heezen|1960}} which would trigger a real revolution in thinking. A profound consequence of seafloor spreading is that new crust was, and still is, being continually created along the oceanic ridges. For this reason, Heezen initially advocated the so-called "[[expanding Earth]]" hypothesis of S. Warren Carey (see above). Therefore, the question remained as to how new crust could continuously be added along the oceanic ridges without increasing the size of Earth. In reality, this question had been solved already by numerous scientists during the 1940s and the 1950s, like Arthur Holmes, Vening-Meinesz, Coates and many others: The crust in excess disappeared along what were called the oceanic trenches, where so-called "subduction" occurred. Therefore, when various scientists during the early 1960s started to reason on the data at their disposal regarding the ocean floor, the pieces of the theory quickly fell into place.

The question particularly intrigued [[Harry Hammond Hess]], a [[Princeton University]] geologist and a Naval Reserve Rear Admiral, and [[Robert S. Dietz]], a scientist with the [[United States Coast and Geodetic Survey]] who coined the term ''seafloor spreading''. Dietz and Hess (the former published the same idea one year earlier in ''[[Nature (journal)|Nature]]'',{{sfn|Dietz|1961}} but priority belongs to Hess who had already distributed an unpublished manuscript of his 1962 article by 1960){{sfn|Hess|1962}} were among the small number who really understood the broad implications of sea floor spreading and how it would eventually agree with the, at that time, unconventional and unaccepted ideas of continental drift and the elegant and mobilistic models proposed by previous workers like Holmes.

In the same year, [[Robert R. Coats]] of the U.S. Geological Survey described the main features of [[island arc]] subduction in the [[Aleutian Islands]].{{sfn|Coates|1962}} His paper, though little noted (and sometimes even ridiculed) at the time, has since been called "seminal" and "prescient". In reality, it shows that the work by the European scientists on island arcs and mountain belts performed and published during the 1930s up until the 1950s was applied and appreciated also in the United States.

If Earth's crust was expanding along the oceanic ridges, Hess and Dietz reasoned like Holmes and others before them, it must be shrinking elsewhere. Hess followed Heezen, suggesting that new oceanic crust continuously spreads away from the ridges in a conveyor belt–like motion. And, using the mobilistic concepts developed before, he correctly concluded that many millions of years later, the oceanic crust eventually descends along the continental margins where oceanic trenches—very deep, narrow canyons—are formed, e.g. along [[Pacific Ring of Fire|the rim of the Pacific Ocean basin]]. The important step Hess made was that convection currents would be the driving force in this process, arriving at the same conclusions as Holmes had decades before with the only difference that the thinning of the ocean crust was performed using Heezen's mechanism of spreading along the ridges. Hess therefore concluded that the Atlantic Ocean was expanding while the [[Pacific Ocean]] was shrinking. As old oceanic crust is "consumed" in the trenches (like Holmes and others, he thought this was done by thickening of the continental lithosphere, not, as later understood, by underthrusting at a larger scale of the oceanic crust itself into the mantle), new magma rises and erupts along the spreading ridges to form new crust. In effect, the ocean basins are perpetually being "recycled", with the forming of new crust and the destruction of old oceanic lithosphere occurring simultaneously. Thus, the new mobilistic concepts neatly explained why Earth does not get bigger with sea floor spreading, why there is so little sediment accumulation on the ocean floor, and why oceanic rocks are much younger than continental rocks.

=== Magnetic striping ===
[[File:Oceanic.Stripe.Magnetic.Anomalies.Scheme.svg|thumb|Seafloor magnetic striping]]
[[File:Polarityshift.gif|thumb|A demonstration of magnetic striping. The darker the color is, the closer it is to normal polarity.]]
{{Further|Vine–Matthews–Morley hypothesis}}

Beginning in the 1950s, scientists like [[Victor Vacquier]], using magnetic instruments ([[magnetometer]]s) adapted from airborne devices developed during [[World War II]] to detect [[submarine]]s, began recognizing odd magnetic variations across the ocean floor. This finding, though unexpected, was not entirely surprising because it was known that [[basalt]]—the iron-rich, volcanic rock making up the ocean floor—contains a strongly magnetic mineral ([[magnetite]]) and can locally distort compass readings. This distortion was recognized by Icelandic mariners as early as the late 18th century. More importantly, because the presence of magnetite gives the basalt measurable magnetic properties, these newly discovered magnetic variations provided another means to study the deep ocean floor. When newly formed rock cools, such magnetic materials recorded [[Earth's magnetic field]] at the time.

As more and more of the seafloor was mapped during the 1950s, the magnetic variations turned out not to be random or isolated occurrences, but instead revealed recognizable patterns. When these magnetic patterns were mapped over a wide region, the ocean floor showed a [[zebra]]-like pattern: one stripe with normal polarity and the adjoining stripe with reversed polarity. The overall pattern, defined by these alternating bands of normally and reversely polarized rock, became known as magnetic striping, and was published by [[Ron G. Mason]] and co-workers in 1961, who did not find, though, an explanation for these data in terms of sea floor spreading, like Vine, Matthews and Morley a few years later.<ref>{{Harvnb|Mason|Raff|1961}}, {{Harvnb|Raff|Mason|1961}}.</ref>

The discovery of magnetic striping called for an explanation. In the early 1960s scientists such as Heezen, Hess and Dietz had begun to theorise that mid-ocean ridges mark structurally weak zones where the ocean floor was being ripped in two lengthwise along the ridge crest (see the previous paragraph). New [[magma]] from deep within Earth rises easily through these weak zones and eventually erupts along the crest of the ridges to create new oceanic crust. This process, at first denominated the "conveyer belt hypothesis" and later called seafloor spreading, operating over many millions of years continues to form new ocean floor all across the 50,000&nbsp;km-long system of mid-ocean ridges.

Only four years after the maps with the "zebra pattern" of magnetic stripes were published, the link between sea floor spreading and these patterns was recognized independently by [[Lawrence Morley]], and by [[Fred Vine]] and [[Drummond Matthews]], in 1963,{{sfn|Vine|Matthews|1963}} (the [[Vine–Matthews–Morley hypothesis]]). This hypothesis linked these patterns to geomagnetic reversals and was supported by several lines of evidence:<ref>See summary in {{Harvnb|Heirtzler|Le Pichon|Baron|1966}}</ref>
# the stripes are symmetrical around the crests of the mid-ocean ridges; at or near the crest of the ridge, the rocks are very young, and they become progressively older away from the ridge crest;
# the youngest rocks at the ridge crest always have modern (normal) polarity;
# stripes of rock parallel to the ridge crest alternate in magnetic polarity (normal-reversed-normal, etc.), suggesting that they were formed during different epochs documenting the (already known from independent studies) normal and reversal episodes of Earth's magnetic field.

By explaining both the zebra-like magnetic striping and the construction of the mid-ocean ridge system, the seafloor spreading hypothesis (SFS) quickly gained converts and represented another major advance in the development of the plate-tectonics theory. Furthermore, the oceanic crust came to be appreciated as a natural "tape recording" of the history of the geomagnetic field reversals (GMFR) of Earth's magnetic field. Extensive studies were dedicated to the calibration of the normal-reversal patterns in the oceanic crust on one hand and known timescales derived from the dating of basalt layers in sedimentary sequences ([[magnetostratigraphy]]) on the other, to arrive at estimates of past spreading rates and plate reconstructions.

=== Definition and refining of the theory ===
After all these considerations, plate tectonics (or, as it was initially called "New Global Tectonics") became quickly accepted and numerous papers followed that defined the concepts:

* In 1965, [[Tuzo Wilson]] who had been a promoter of the sea floor spreading hypothesis and continental drift from the very beginning{{sfn|Wilson|1963}} added the concept of [[transform fault]]s to the model, completing the classes of fault types necessary to make the mobility of the plates on the globe work out.{{sfn|Wilson|1965}}
* A symposium on continental drift was held at the Royal Society of London in 1965 which must be regarded as the official start of the acceptance of plate tectonics by the scientific community, and which abstracts are issued as {{Harvtxt|Blackett|Bullard|Runcorn|1965}}. In this symposium, [[Edward Bullard]] and co-workers showed with a computer calculation how the continents along both sides of the Atlantic would best fit to close the ocean, which became known as the famous "Bullard's Fit".
* In 1966 Wilson published the paper that referred to previous plate tectonic reconstructions, introducing the concept of what became known as the "[[Wilson Cycle]]".{{sfn|Wilson|1966}}
* In 1967, at the [[American Geophysical Union]]'s meeting, [[W. Jason Morgan]] proposed that Earth's surface consists of 12 rigid plates that move relative to each other.{{sfn|Morgan|1968}}
* Two months later, [[Xavier Le Pichon]] published a complete model based on six major plates with their relative motions, which marked the final acceptance by the scientific community of plate tectonics.{{sfn|Le Pichon|1968}}
* In the same year, [[Dan McKenzie (geophysicist)|McKenzie]] and [[Robert Ladislav Parker|Parker]] independently presented a model similar to Morgan's using translations and rotations on a sphere to define the plate motions.{{sfn|McKenzie|Parker|1967}}
* From that moment onwards, discussions have been focusing on the relative role of the forces driving plate tectonics, in order to evolve from a kinematic concept into a dynamic theory.<ref>Tharp M (1982) Mapping the ocean floor—1947 to 1977. In: The ocean floor: Bruce Heezen commemorative volume, pp. 19–31. New York: Wiley.</ref> Initially these concepts were focused on mantle convection, in the footsteps of A. Holmes, and also introduced the importance of the gravitational pull of subducted slabs through the works of Elsasser, Solomon, Sleep, Uyeda and Turcotte. Other authors evoked external driving forces due to the tidal drag of the Moon and other celestial bodies, and, especially since 2000, with the emergence of computational models reproducing Earth's mantle behaviour to first order,<ref>{{Cite journal |last1=Coltice |first1=Nicolas |last2=Gérault |first2=Mélanie |last3=Ulvrová |first3=Martina |date=2017 |title=A mantle convection perspective on global tectonics |journal=Earth-Science Reviews |volume=165 |pages=120–150 |bibcode=2017ESRv..165..120C |doi=10.1016/j.earscirev.2016.11.006}}</ref><ref>{{Cite journal |last=Bercovici |first=David |date=2003 |title=The generation of plate tectonics from mantle convection |journal=Earth and Planetary Science Letters |volume=205 |issue=3–4 |pages=107–121 |bibcode=2003E&PSL.205..107B |doi=10.1016/S0012-821X(02)01009-9}}</ref> following upon the older unifying concepts of van Bemmelen, authors re-evaluated the important role of mantle dynamics.<ref>{{Cite journal |last1=Crameri |first1=Fabio |last2=Conrad |first2=Clinton P. |last3=Montési |first3=Laurent |last4=Lithgow-Bertelloni |first4=Carolina R. |date=2019 |title=The dynamic life of an oceanic plate |journal=Tectonophysics |volume=760 |pages=107–135 |bibcode=2019Tectp.760..107C |doi=10.1016/j.tecto.2018.03.016|hdl=10852/72186 |hdl-access=free }}</ref>

== Implications for life ==
According to a hypothesis proposed by Robert Stern and Taras Gerya, plate tectonics are a necessary criterion for a planet to be able to sustain complex life because of the role plate tectonics plays in regulating the carbon cycle.<ref>{{Cite journal |last1=Stern |first1=Robert J. |last2=Gerya |first2=Taras V. |date=12 April 2024 |title=The importance of continents, oceans and plate tectonics for the evolution of complex life: implications for finding extraterrestrial civilizations |journal=[[Scientific Reports]] |language=en |volume=14 |issue=1 |page=8552 |doi=10.1038/s41598-024-54700-x |pmid=38609425 |issn=2045-2322 |pmc=11015018 |bibcode=2024NatSR..14.8552S }}</ref>

Continental drift theory helps biogeographers to explain the disjunct [[biogeographic]] distribution of present-day life found on different continents but having [[Common descent|similar ancestors]].{{sfn|Moss|Wilson|1998}}

== Plate reconstruction ==
{{Main|Plate reconstruction}}
Reconstruction is used to establish past (and future) plate configurations, helping determine the shape and make-up of ancient supercontinents and providing a basis for paleogeography.

=== Defining plate boundaries ===
Active plate boundaries are defined by their seismicity.{{sfn|Condie|1997}} Past plate boundaries within existing plates are identified from a variety of evidence, such as the presence of [[ophiolites]] that are indicative of vanished oceans.{{sfn|Lliboutry|2000}}

=== Emergence of plate tectonics and past plate motions ===
The timing of the emergence of plate tectonics on Earth has been the subject of considerable controversy, with the estimated time varying wildly between researchers, spanning 85% of Earth's history.<ref name=":0">{{Cite journal |last=Marshall |first=Michael |date=2024-08-14 |title=Geology's biggest mystery: when did plate tectonics start to reshape Earth? |journal=Nature |language=en |volume=632 |issue=8025 |pages=490–492 |doi=10.1038/d41586-024-02602-3|pmid=39143339 |bibcode=2024Natur.632..490M |doi-access=free }}</ref> Some authors have suggested that during at least part of the [[Archean]] period (~4-2.5 billion years ago) the mantle was between 100 and 250&nbsp;°C warmer than at present, which is thought to be incompatible with modern-style plate tectonics, and that Earth may have had a [[stagnant lid]] or other kinds of regimes. The increasingly [[felsic]] nature of preserved rocks between 3 and 2.5 billion years ago implies that subduction zones had emerged by this time, with preserved zircons suggesting that subduction may have begun as early as 3.8 billion years ago. Early subduction zones appear to have been temporary and localized, though to what degree is controversial. Modern plate tectonics are suggested to have emerged by at least 2.2 billion years ago with the formation of the first recognised supercontinent Columbia, though some authors have suggested that modern-style plate tectonics did not appear until 800 million years ago based on the late appearance of rock types like [[blueschist]] which require cold subducted material.<ref name=":0" /> Other authors have suggested that plate tectonics were already functional in the [[Hadean]], over 4 billion years ago.<ref>{{Cite journal |last=Korenaga |first=Jun |date=July 2021 |title=Hadean geodynamics and the nature of early continental crust |url=https://linkinghub.elsevier.com/retrieve/pii/S0301926821001066 |journal=Precambrian Research |language=en |volume=359 |article-number=106178 |doi=10.1016/j.precamres.2021.106178|bibcode=2021PreR..35906178K |url-access=subscription }}</ref>
[[File:Tectonic plate model 1Ga.webm|thumb|upright=1.6|right|Animation of a full-plate tectonic model extended one billion years into the past <br />
{{legend-line|#ac1f25 solid 3px|{{0}}Convergent boundary}}
{{legend-line|#a08eda solid 3px|{{0}}Divergent boundary}}
{{legend-line|#000000 solid 3px|{{0}}Transform boundary}}
{{Legend striped|#ac1f25|#ffffff00|border=none|{{0}}{{0}}Arrows point to the upthrown side}}
{{legend|#b5b71f|{{0}} [[Continental crust]] (older crust)}}
{{legend|#6f8ebf|{{0}} Continental crust (younger crust)}}
{{legend|#ffffff|{{0}} [[Oceanic crust]]}} ]]

Various types of quantitative and semi-quantitative information are available to constrain past plate motions. The geometric fit between continents, such as between west Africa and South America is still an important part of plate reconstruction. Magnetic stripe patterns provide a reliable guide to relative plate motions going back into the [[Jurassic]] period.<ref>{{Cite web |last=Torsvik |first=Trond Helge |title=Reconstruction Methods |url=http://www.geodynamics.no/GMAP/Methods/Introduction_to_Methods.htm |url-status=live |archive-url=https://web.archive.org/web/20110723121811/http://www.geodynamics.no/GMAP/Methods/Introduction_to_Methods.htm |archive-date=23 July 2011 |access-date=18 June 2010}}</ref> The tracks of hotspots give absolute reconstructions, but these are only available back to the [[Cretaceous]].{{sfn|Torsvik|Steinberger|2008}} Older reconstructions rely mainly on [[paleomagnetic pole]] data, although these only constrain the latitude and rotation, but not the longitude. Combining poles of different ages in a particular plate to produce apparent polar wander paths provides a method for comparing the motions of different plates through time.{{sfn|Butler|1992}} Additional evidence comes from the distribution of certain [[sedimentary rock]] types,<ref>{{Cite web |last=Scotese |first=C.R. |date=2002-04-20 |title=Climate History |url=http://www.scotese.com/climate.htm |url-status=live |archive-url=https://web.archive.org/web/20100615150530/http://www.scotese.com/climate.htm |archive-date=15 June 2010 |access-date=18 June 2010 |website=Paleomap Project}}</ref> faunal provinces shown by particular fossil groups, and the position of [[orogeny|orogenic belts]].{{sfn|Torsvik|Steinberger|2008}}

==== Formation and break-up of continents ====
The movement of plates has caused the formation and break-up of continents over time, including occasional formation of a [[supercontinent]] that contains most or all of the continents. The supercontinent [[Columbia (supercontinent)|Columbia]] or Nuna formed during a period of {{Ma|2000|1800}} and broke up about {{Ma|1500|1300}}.{{sfn|Zhao|Cawood|Wilde|Sun|2002}}{{sfn|Zhao|Sun|Wilde|Li|2004}} The supercontinent [[Rodinia]] is thought to have formed about 1{{nbsp}}billion years ago and to have embodied most or all of Earth's continents, and broken up into eight continents around {{Ma|600}}. The eight continents later re-assembled into another supercontinent called [[Pangaea]]; Pangaea broke up into [[Laurasia]] (which became North America and Eurasia) and [[Gondwana]] (which became the remaining continents).

The [[Himalayas]], the world's tallest mountain range, are assumed to have been formed by the collision of two major plates. Before uplift, the area where they stand was covered by the [[Tethys Ocean]].

== Modern plates ==
{{Main|List of tectonic plates}}
[[File:Plate tectonics map.gif|frameless|upright=2|right|Plate tectonics map]]

Depending on how they are defined, there are usually seven or eight "major" plates: [[African plate|African]], [[Antarctic plate|Antarctic]], [[Eurasian plate|Eurasian]], [[North American plate|North American]], [[South American plate|South American]], [[Pacific plate|Pacific]], and [[Indo-Australian plate|Indo-Australian]]. The latter is sometimes subdivided into the [[Indian plate|Indian]] and [[Australian plate|Australian]] plates.

There are dozens of smaller plates, the eight largest of which are the [[Arabian plate|Arabian]], [[Caribbean plate|Caribbean]], [[Juan de Fuca plate|Juan de Fuca]], [[Cocos plate|Cocos]], [[Nazca plate|Nazca]], [[Philippine Sea plate|Philippine Sea]], [[Scotia plate|Scotia]] and [[Somali plate|Somali]].

During the 2020s, new proposals have come forward that divide Earth's crust into many smaller plates, called terranes, which reflects the fact that Plate reconstructions show that the larger plates have been internally deformed and oceanic and continental plates have been fragmented over time. This has resulted in the definition of roughly 1200 terranes inside the oceanic plates, continental blocks and the mobile zones (mountainous belts) that separate them.<ref name="Hasterok-etal_2022">{{Cite journal |last1=Hasterok |first1=Derrick |last2=Halpin |first2=Jacqueline A. |last3=Collins |first3=Alan S. |last4=Hand |first4=Martin |last5=Kreemer |first5=Corné |last6=Gard |first6=Matthew G. |last7=Glorie |first7=Stijn |date=2022 |title=New Maps of Global Geological Provinces and Tectonic Plates |journal=Earth-Science Reviews |volume=231 |bibcode=2022ESRv..23104069H |doi=10.1016/j.earscirev.2022.104069}}</ref><ref name="van Dijk_2023">{{Cite journal |last=Van Dijk |first=Janpieter |date=2023 |title=The new global tectonic map—Analyses and implications |journal=Terra Nova |volume=35 |issue=5 |pages=343–369 |bibcode=2023TeNov..35..343V |doi=10.1111/TER.12662}}</ref>

The motion of the tectonic plates is determined by remote sensing satellite data sets, calibrated with ground station measurements.

== Other celestial bodies ==
The appearance of plate tectonics on [[terrestrial planet]]s is related to planetary mass, with [[super-Earth|more massive planets than Earth]] expected to exhibit plate tectonics. Earth may be a borderline case, owing its tectonic activity to abundant water (silica and water form a deep [[eutectic]]).{{sfn|Valencia|O'Connell|Sasselov|2007}}

=== Venus ===
{{See also|Geology of Venus}}
Venus shows no evidence of active plate tectonics. There is debatable evidence of active tectonics in the planet's distant past; however, events taking place since then (such as the plausible and generally accepted hypothesis that the Venusian [[lithosphere]] has thickened greatly over the course of several hundred million years) has made constraining the course of its geologic record difficult. However, the numerous well-preserved [[impact crater]]s have been used as a [[dating methods|dating method]] to approximately date the Venusian surface (since there are thus far no known samples of Venusian rock to be dated by more reliable methods). Dates derived are dominantly in the range {{Ma|500|750}}, although ages of up to {{Ma|1200}} have been calculated. This research has led to the fairly well accepted hypothesis that Venus has undergone an essentially complete volcanic resurfacing at least once in its distant past, with the last event taking place approximately within the range of estimated surface ages. While the mechanism of such an impressive thermal event remains a debated issue in Venusian geosciences, some scientists are advocates of processes involving plate motion to some extent.

One explanation for Venus's lack of plate tectonics is that on Venus temperatures are too high for significant water to be present.{{sfn|Kasting|1988}}<ref>{{Cite web |last=Bortman |first=Henry |date=2004-08-26 |title=Was Venus alive? 'The Signs are Probably There' |url=http://www.space.com/scienceastronomy/venus_life_040826.html |url-status=live |archive-url=https://web.archive.org/web/20101224055407/http://www.space.com/scienceastronomy/venus_life_040826.html |archive-date=2010-12-24 |access-date=2008-01-08 |website=Space.com}}</ref> Earth's crust is soaked with water, and water plays an important role in the development of [[shear zone]]s. Plate tectonics requires weak surfaces in the crust along which crustal slices can move, and it may well be that such weakening never took place on Venus because of the absence of water. However, some researchers<ref>{{cite journal|author1=Weller, M.B.|author2= Evans, A.J.|author3= Ibarra, D.E.|title= Venus's atmospheric nitrogen explained by ancient plate tectonics|journal= Nat Astron|volume= 7|pages=1436–1444|year=2023|issue= 12|doi= 10.1038/s41550-023-02102-w|bibcode= 2023NatAs...7.1436W}}</ref> remain convinced that plate tectonics is or was once active on this planet.

=== Mars ===
{{See also|Geology of Mars}}
Mars is considerably smaller than Earth and Venus, and there is evidence for ice on its surface and in its crust.

In the 1990s, it was proposed that [[Martian dichotomy|Martian Crustal Dichotomy]] was created by plate tectonic processes.{{sfn|Sleep|1994}} Scientists have since determined that it was created either by upwelling within the Martian [[mantle (geology)|mantle]] that thickened the crust of the Southern Highlands and formed [[Tharsis]]{{sfn|Zhong|Zuber|2001}} or by a giant impact that excavated the [[Vastitas Borealis|Northern Lowlands]].{{sfn|Andrews-Hanna|Zuber|Banerdt|2008}}

[[Valles Marineris]] may be a tectonic boundary.<ref name="tectonic">{{Cite web |last=Wolpert, Stuart |date=August 9, 2012 |title=UCLA scientist discovers plate tectonics on Mars |url=http://newsroom.ucla.edu/portal/ucla/ucla-scientist-discovers-plate-237303.aspx?link_page_rss=237303 |archive-url=https://web.archive.org/web/20120814232327/http://newsroom.ucla.edu/portal/ucla/ucla-scientist-discovers-plate-237303.aspx?link_page_rss=237303 |archive-date=August 14, 2012 |access-date=August 13, 2012 |website=Yin, An |publisher=[[UCLA]]}}</ref>

Observations made of the magnetic field of Mars by the ''[[Mars Global Surveyor]]'' spacecraft in 1999 showed patterns of magnetic striping discovered on this planet. Some scientists interpreted these as requiring plate tectonic processes, such as seafloor spreading.<ref>{{Harvnb|Connerney|Acuña|Wasilewski|Ness|1999}}, {{Harvnb|Connerney|Acuña|Ness|Kletetschka|2005}}</ref> However, their data failed a "magnetic reversal test", which is used to see if they were formed by flipping polarities of a global magnetic field.{{sfn|Harrison|2000}}

=== Icy moons ===
{{excerpt|Tectonics on icy moons|Plate tectonics}}

=== Exoplanets ===
On Earth-sized planets, plate tectonics is more likely if there are oceans of water. However, in 2007, two independent teams of researchers came to opposing conclusions about the likelihood of plate tectonics on larger [[super-Earth]]s<ref>{{Cite journal |last1=Valencia |first1=Diana |last2=O'Connell |first2=Richard J. |year=2009 |title=Convection scaling and subduction on Earth and super-Earths |journal=[[Earth and Planetary Science Letters]] |volume=286 |issue=3–4 |pages=492–502 |bibcode=2009E&PSL.286..492V |doi=10.1016/j.epsl.2009.07.015}}</ref><ref>{{Cite journal |last1=van Heck |first1=H.J. |last2=Tackley |first2=P.J. |year=2011 |title=Plate tectonics on super-Earths: Equally or more likely than on Earth |journal=[[Earth and Planetary Science Letters]] |volume=310 |issue=3–4 |pages=252–61 |bibcode=2011E&PSL.310..252V |doi=10.1016/j.epsl.2011.07.029}}</ref> with one team saying that plate tectonics would be episodic or stagnant<ref>{{Cite journal |last1=O'Neill |first1=C. |last2=Lenardic |first2=A. |year=2007 |title=Geological consequences of super-sized Earths |journal=[[Geophysical Research Letters]] |volume=34 |issue=19 |page=L19204 |bibcode=2007GeoRL..3419204O |doi=10.1029/2007GL030598 |doi-access=free}}</ref> and the other team saying that plate tectonics is very likely on super-earths even if the planet is dry.{{sfn|Valencia|O'Connell|Sasselov|2007}}

Consideration of plate tectonics is a part of the [[search for extraterrestrial intelligence]] and [[extraterrestrial life]].<ref>{{Cite journal |last=Stern |first=Robert J. |date=July 2016 |title=Is plate tectonics needed to evolve technological species on exoplanets? |journal=[[Geoscience Frontiers]] |volume=7 |issue=4 |pages=573–580 |bibcode=2016GeoFr...7..573S |doi=10.1016/j.gsf.2015.12.002 |doi-access=free}}</ref>

== See also ==
{{Div col |colwidth=27em}}
* {{annotated link|Atmospheric circulation}}
* {{annotated link|Angular momentum#Conservation of angular momentum|Conservation of angular momentum}}
* {{annotated link|Geological history of Earth}}
* {{annotated link|Geosyncline}}
* {{annotated link|GPlates}}
* {{annotated link|List of submarine topographical features}}
* {{annotated link|Outline of plate tectonics}}
* {{annotated link|Supercontinent cycle}}
* {{annotated link|Tectonics}}
{{Div col end}}

== References ==
=== Citations ===
{{reflist}}

=== Sources ===
==== Books ====
{{refbegin|33em}}
* {{Cite book |last=Butler |first=Robert F. |title=Paleomagnetism: Magnetic domains to geologic terranes |publisher=[[Wiley-Blackwell|Blackwell]] |year=1992 |isbn=978-0-86542-070-0 |chapter=Applications to paleogeography |access-date=18 June 2010 |chapter-url=http://www.geo.arizona.edu/Paleomag/book/chap10.pdf |archive-url=https://web.archive.org/web/20100817084001/http://www.geo.arizona.edu/Paleomag/book/chap10.pdf |archive-date=17 August 2010 }}
* {{Cite book |last=Carey |first=S.W. |title=Continental Drift – A symposium, held in March 1956 |publisher=[[University of Tasmania]] |year=1958 |editor-last=Carey |editor-first=S.W. |location=Hobart, Tasmania |pages=177–363 |chapter=The tectonic approach to continental drift}} Expanding Earth from pp.&nbsp;311–49.
* {{Cite book |last=Condie |first=K.C. |url=https://books.google.com/books?id=QfhGuFwi0DgC&pg=PA6 |title=Plate tectonics and crustal evolution |publisher=Butterworth-Heinemann |year=1997 |isbn=978-0-7506-3386-4 |edition=4th |page=282 |access-date=2010-06-18}}
* {{Cite book |last=Foulger |first=Gillian R. |title=Plates vs Plumes: A Geological Controversy |publisher=[[Wiley-Blackwell]] |year=2010 |isbn=978-1-4051-6148-0}}
* {{Cite book |last=Frankel |first=H. |title=Scientific Controversies: Case Studies in the Resolution and Closure of Disputes in Science and Technology |publisher=[[Cambridge University Press]] |year=1987 |isbn=978-0-521-27560-6 |editor-last=H.T. Engelhardt Jr |chapter=The Continental Drift Debate |editor-last2=A.L. Caplan |chapter-url=https://books.google.com/books?id=lp_n-Ng-hhoC&pg=PA203}}
* {{Cite book |last1=Hancock |first1=Paul L. |url=https://archive.org/details/oxfordcompaniont00hanc |title=The Oxford Companion to The Earth |last2=Skinner |first2=Brian J. |last3=Dineley |first3=David L. |publisher=[[Oxford University Press]] |year=2000 |isbn=978-0-19-854039-7}}
* {{Cite book |last=Hess |first=H.H. |title=Petrologic studies: a volume to honor of A.F. Buddington |date=November 1962 |publisher=[[Geological Society of America]] |editor-last=A.E.J. Engel |location=Boulder, CO |pages=599–620 |chapter=History of Ocean Basins |editor-last2=Harold L. James |editor-last3=B.F. Leonard |chapter-url=http://www.mantleplumes.org/WebDocuments/Hess1962.pdf}}
* {{Cite book |last=Holmes |first=Arthur |author-link=Arthur Holmes |title=Principles of Physical Geology |publisher=[[Wiley (publisher)|Wiley]] |year=1978 |isbn=978-0-471-07251-5 |edition=3rd |pages=640–41}}
* {{Cite book |last=Joly |first=John |author-link=John Joly |url=https://books.google.com/books?id=GihJAAAAIAAJ&pg=PA36 |title=Radioactivity and Geology: An Account of the Influence of Radioactive Energy on Terrestrial History |publisher=Archibald Constable & Company | year=2004 |orig-date=1909 |isbn=978-1-4021-3577-4 |location=London |page=36}} ({{Cite journal |last=Joly |first=J. |year=1910 |title=Review of ''Radioactivity and Geology'' |journal=[[Journal of Geology]] |volume=18 |issue=6 |pages=568–570 |bibcode=1910JG.....18..568J |doi=10.1086/621777}})
* {{Cite book |last1=Kious |first1=W. Jacquelyne |url=https://pubs.usgs.gov/gip/dynamic/dynamic.html |title=This Dynamic Earth: the Story of Plate Tectonics |last2=Tilling |first2=Robert I. |date=February 1996 |publisher=United States Geological Survey |isbn=978-0-16-048220-5 |edition=Online |chapter=Historical perspective |quote=[[Abraham Ortelius]] in his work Thesaurus Geographicus... suggested that the Americas were 'torn away from Europe and Africa... by earthquakes and floods... The vestiges of the rupture reveal themselves, if someone brings forward a map of the world and considers carefully the coasts of the three [continents].' |access-date=2008-01-29 |chapter-url=https://pubs.usgs.gov/gip/dynamic/historical.html}}
* {{Cite book |last=Lippsett |first=Laurence |title=Living Legacies at Columbia |publisher=[[Columbia University Press]] |year=2006 |isbn=978-0-231-13884-0 |editor-last=William Theodore De Bary |pages=277–97 |chapter=Maurice Ewing and the Lamont–Doherty Earth Observatory |access-date=2010-06-22 |editor-last2=Jerry Kisslinger |editor-last3=Tom Mathewson |chapter-url=https://books.google.com/books?id=l1os3mwQkxYC&pg=PR9}}
* {{Cite book |last1=Little |first1=W. |url=https://archive.org/details/shorteroxfordeng00litt |title=The Shorter Oxford English Dictionary: on historical principles |last2=Fowler |first2=H.W. |last3=Coulson |first3=J. |publisher=[[Clarendon Press]] |year=1990 |isbn=978-0-19-861126-4 |editor-last=Onions C.T. |edition=3rd |volume=II}}
* {{Cite book |last=Lliboutry |first=L. |year=2000 |title=Quantitative Geophysics and Geology |publisher=Springer |url=https://books.google.com/books?id=C7rny3qA6RMC&pg=PA133 |isbn=978-1-85233-115-3 |access-date=2010-06-18}}
* {{Cite book |last=McKnight |first=Tom |title=Geographica: The complete illustrated Atlas of the world |publisher=[[Barnes and Noble Books]] |year=2004 |isbn=978-0-7607-5974-5 |location=New York, NY}}
* {{Cite book |last=Meissner |first=Rolf |title=The Little Book of Planet Earth |publisher=[[Springer Verlag|Copernicus Books]] |year=2002 |isbn=978-0-387-95258-1 |location=[[New York City|New York]], NY |page=202}}
* {{Cite book |last1=Meyerhoff |first1=Arthur Augustus |url=https://books.google.com/books?id=IVIBPWyT7BkC |title=Surge tectonics: a new hypothesis of global geodynamics |last2=Taner |first2=I. |last3=Morris |first3=A.E.L. |last4=Agocs |first4=W.B. |last5=Kamen-Kaye |first5=M. |last6=Bhat |first6=Mohammad I. |last7=Smoot |first7=N. Christian |last8=Choi |first8=Dong R. |publisher=Springer Netherlands |year=1996 |isbn=978-0-7923-4156-7 |editor-last=Donna Meyerhoff Hull |series=Solid Earth Sciences Library |volume=9 |page=348}}
* {{Cite book |last1=Moss |first1=S.J. |title=Biogeography and Geological Evolution of SE Asia |last2=Wilson |first2=M.E.J. |publisher=Backhuys |year=1998 |isbn=978-90-73348-97-4 |editor-last=Hall |editor-first=R. |location=Leiden, The Netherlands |pages=133–63 |chapter=Biogeographic implications from the Tertiary palaeogeographic evolution of Sulawesi and Borneo |access-date=2008-01-29 |editor-last2=Holloway |editor-first2=J.D. |chapter-url=http://www.gl.rhul.ac.uk/searg/publications/books/biogeography/biogeog_pdfs/Moss_Wilson.pdf |archive-url=https://web.archive.org/web/20080216095932/http://www.gl.rhul.ac.uk/searg/publications/books/biogeography/biogeog_pdfs/Moss_Wilson.pdf |archive-date=2008-02-16 }}
* {{Cite book |title=Plate Tectonics: An Insider's History of the Modern Theory of the Earth |publisher=Westview |year=2003 |isbn=978-0-8133-4132-3 |editor-last=Oreskes |editor-first=Naomi |editor-link=Naomi Oreskes}}
* {{Cite book |last1=Read |first1=Herbert Harold |url=https://archive.org/details/introductiontoge0000read/page/13 |title=Introduction to Geology |last2=Watson |first2=Janet |publisher=Halsted |year=1975 |isbn=978-0-470-71165-1 |location=New York, NY |pages=[https://archive.org/details/introductiontoge0000read/page/13 13–15] |oclc=317775677}}
* {{Cite book |last1=Schmidt |first1=Victor A. |url=http://geoinfo.amu.edu.pl/wpk/pe/a/harbbook/other/contents.html |title=Planet Earth and the New Geosciences |last2=Harbert |first2=William |publisher=Kendall/Hunt Publishing Company |year=1998 |isbn=978-0-7872-4296-1 |edition=3rd |page=442 |chapter=The Living Machine: Plate Tectonics |access-date=2008-01-28 |archive-url=https://web.archive.org/web/20100124060304/http://geoinfo.amu.edu.pl/wpk/pe/a/harbbook/other/contents.html |archive-date=2010-01-24 }} {{Cite web |title=Unit 3: The Living Machine: Plate Tectonics |url=http://geoinfo.amu.edu.pl/wpk/pe/a/harbbook/c_iii/chap03.html |archive-url=https://web.archive.org/web/20100328212854/http://geoinfo.amu.edu.pl/wpk/pe/a/harbbook/c_iii/chap03.html |archive-date=2010-03-28}}
* {{Cite book |last1=Schubert |first1=Gerald |title=Mantle Convection in the Earth and Planets |last2=Turcotte |first2=Donald L. |last3=Olson |first3=Peter |publisher=[[Cambridge University Press]] |year=2001 |isbn=978-0-521-35367-0 |location=Cambridge, England}}
* {{Cite book |last=Stanley |first=Steven M. |title=Earth System History |publisher=[[W.H. Freeman]] |year=1999 |isbn=978-0-7167-2882-5 |pages=211–28}}
* {{Cite book |last1=Stein |first1=Seth |title=An Introduction to Seismology, Earthquakes, and Earth Structure |last2=Wysession |first2=Michael |publisher=John Wiley & Sons |year=2009 |isbn=978-1-4443-1131-0 |location=Chichester}}
* {{Cite book |last1=Sverdrup |first1=H.U. |title=The Oceans: Their physics, chemistry and general biology |last2=Johnson |first2=M.W. |last3=Fleming |first3=R.H. |publisher=[[Prentice-Hall]] |year=1942 |location=Englewood Cliffs |page=1087}}
* {{Cite book |last1=Thompson |first1=Graham R. |url=https://archive.org/details/modernphysicalge0000thom |title=Modern Physical Geology |last2=Turk |first2=Jonathan |publisher=[[Saunders College Publishing]] |year=1991 |isbn=978-0-03-025398-0 |name-list-style=amp}}
* {{Cite journal |last1=Torsvik |first1=Trond Helge |last2=Steinberger |first2=Bernhard |date=December 2006 |title=Fra kontinentaldrift til manteldynamikk |trans-title=From Continental Drift to Mantle Dynamics |url=http://www.geodynamics.no/indexOld.htm |journal=Geo |language=no |volume=8 |pages=20–30 |archive-url=https://web.archive.org/web/20110723122146/http://www.geodynamics.no/indexOld.htm |archive-date=23 July 2011 |access-date=22 June 2010}},<br />translation: {{Cite book |last1=Torsvik |first1=Trond Helge |title=Geology for Society for 150 years – The Legacy after Kjerulf |last2=Steinberger |first2=Bernhard |publisher=[[Norges Geologiske Undersokelse]] |year=2008 |editor-last=Trond Slagstad |volume=12 |location=Trondheim |pages=24–38 |chapter=From Continental Drift to Mantle Dynamics |editor-last2=Rolv Dahl Gråsteinen |chapter-url=http://www.geodynamics.no/guest/Torsvik_SteinbergerGraasteinen12.pdf |archive-url=https://web.archive.org/web/20110723121839/http://www.geodynamics.no/guest/Torsvik_SteinbergerGraasteinen12.pdf |archive-date=23 July 2011}} [Norwegian Geological Survey, Popular Science].
* {{Cite book |last1=Turcotte |first1=D.L. |url=https://archive.org/details/geodynamics00dltu |title=Geodynamics |last2=Schubert |first2=G. |publisher=[[Cambridge University Press]] |year=2002 |isbn=978-0-521-66186-7 |edition=2nd |pages=[https://archive.org/details/geodynamics00dltu/page/n15 1]–21 |chapter=Plate Tectonics |url-access=limited}}
* {{Cite book |last=Wegener |first=Alfred |title=Die Entstehung der Kontinente und Ozeane |title-link=:s:de:Die Entstehung der Kontinente und Ozeane |publisher=Friedrich Vieweg & Sohn Akt. Ges |orig-date=1929 | year=2005|isbn=978-3-443-01056-0 |edition=4th |location=Braunschweig}}
* {{Cite book |last=Wegener |first=Alfred |title=The origin of continents and oceans |publisher=Courier Dover |year=1966 |isbn=978-0-486-61708-4 |page=246 |translator-last=Biram John}}
* {{Cite book |last=Winchester |first=Simon |author-link=Simon Winchester |title=Krakatoa: The Day the World Exploded: August 27, 1883 |title-link=Krakatoa: The Day the World Exploded: August 27, 1883 |publisher=[[HarperCollins]] |year=2003 |isbn=978-0-06-621285-2}}
* {{Cite book |url=https://books.google.com/books?id=-BnTZbh6FJMC |title=Superplumes: Beyond Plate Tectonics |publisher=[[Springer Nature|Springer]] |year=2007 |isbn=978-1-4020-5749-6 |editor-last=Yuen |editor-first=David A. |location=[[Dordrecht]], [[South Holland]] |editor-last2=Maruyama |editor-first2=Shigenori |editor-last3=Karato |editor-first3=Shun-Ichiro |editor-last4=Windley |editor-first4=Brian F.}}
{{refend}}

==== Articles ====
{{refbegin|33em}}
* {{Cite journal |last1=Andrews-Hanna |first1=Jeffrey C. |last2=Zuber |first2=Maria T. |last3=Banerdt |first3=W. Bruce |year=2008 |title=The Borealis basin and the origin of the martian crustal dichotomy |journal=[[Nature (journal)|Nature]] |volume=453 |issue=7199 |pages=1212–15 |bibcode=2008Natur.453.1212A |doi=10.1038/nature07011 |pmid=18580944 |s2cid=1981671}}
* {{Cite book |title=A Symposium on Continental Drift, held in 28 October 1965 |publisher=The Royal Society of London |year=1965 |editor-last=Blackett |editor-first=P.M.S. |series=[[Philosophical Transactions of the Royal Society A]] |volume=258 |page=323 |editor-last2=Bullard |editor-first2=E. |editor-last3=Runcorn |editor-first3=S.K. |issue=1088}}
* {{Cite journal |last=Bostrom |first=R.C. |date=31 December 1971 |title=Westward displacement of the lithosphere |journal=Nature |volume=234 |issue=5331 |pages=536–38 |bibcode=1971Natur.234..536B |doi=10.1038/234536a0 |s2cid=4198436}}
* {{Cite journal |last1=Connerney |first1=J.E.P. |last2=Acuña |first2=M.H. |last3=Wasilewski |first3=P.J. |last4=Ness |first4=N.F. |last5=Rème H. |last6=Mazelle C. |last7=Vignes D. |last8=Lin R.P. |last9=Mitchell D.L. |last10=Cloutier P.A. |year=1999 |title=Magnetic Lineations in the Ancient Crust of Mars |url=https://zenodo.org/record/1231159 |journal=[[Science (journal)|Science]] |volume=284 |issue=5415 |pages=794–98 |bibcode=1999Sci...284..794C |doi=10.1126/science.284.5415.794 |pmid=10221909 }}
* {{Cite journal |last1=Connerney |first1=J.E.P. |last2=Acuña |first2=M.H. |last3=Ness |first3=N.F. |last4=Kletetschka |first4=G. |last5=Mitchell |first5=D.L. |last6=Lin |first6=R.P. |last7=Rème |first7=H. |year=2005 |title=Tectonic implications of Mars crustal magnetism |journal=[[Proceedings of the National Academy of Sciences]] |volume=102 |issue=42 |pages=14970–175 |bibcode=2005PNAS..10214970C |doi=10.1073/pnas.0507469102 |pmc=1250232 |pmid=16217034 |doi-access=free}}
* {{Cite journal |last1=Conrad |first1=Clinton P. |last2=Lithgow-Bertelloni |first2=Carolina |author-link2=Carolina Lithgow-Bertelloni |year=2002 |title=How Mantle Slabs Drive Plate Tectonics |url=http://www.soest.hawaii.edu/GG/FACULTY/conrad/resproj/forces/forces.html |journal=[[Science (journal)|Science]] |volume=298 |issue=5591 |pages=207–09 |bibcode=2002Sci...298..207C |doi=10.1126/science.1074161 |pmid=12364804 |s2cid=36766442 |archive-url=https://web.archive.org/web/20090920140431/http://www.soest.hawaii.edu/GG/FACULTY/conrad/resproj/forces/forces.html |archive-date=September 20, 2009 }}
* {{Cite journal |last=Dietz |first=Robert S. |date=June 1961 |title=Continent and Ocean Basin Evolution by Spreading of the Sea Floor |journal=[[Nature (journal)|Nature]] |volume=190 |issue=4779 |pages=854–57 |bibcode=1961Natur.190..854D |doi=10.1038/190854a0 |s2cid=4288496}}
* {{Cite journal |last1=van Dijk |first1=Janpieter |last2=Okkes |first2=F.W. Mark |year=1990 |title=The analysis of shear zones in Calabria; implications for the geodynamics of the Central Mediterranean |journal=[[Rivista Italiana di Paleontologia e Stratigrafia]] |volume=96 |issue=2–3 |pages=241–70}}
* {{Cite journal |last1=van Dijk |first1=J.P. |last2=Okkes |first2=F.W.M. |year=1991 |title=Neogene tectonostratigraphy and kinematics of Calabrian Basins: implications for the geodynamics of the Central Mediterranean |journal=[[Tectonophysics (journal)|Tectonophysics]] |volume=196 |issue=1 |pages=23–60 |bibcode=1991Tectp.196...23V |doi=10.1016/0040-1951(91)90288-4}}
* {{Cite journal |last=van Dijk |first=Janpieter |year=1992 |title=Late Neogene fore-arc basin evolution in the Calabrian Arc (Central Mediterranean). Tectonic sequence stratigraphy and dynamic geohistory. With special reference to the geology of Central Calabria |url=http://igitur-archive.library.uu.nl/geo/2012-0411-200448/UUindex.html |journal=[[Geologica Ultraiectina]] |volume=92 |page=288 |archive-url=https://web.archive.org/web/20130420210655/http://igitur-archive.library.uu.nl/geo/2012-0411-200448/UUindex.html |archive-date=2013-04-20 }}
* {{Cite journal |last=Frankel |first=Henry |date=July 1978 |title=Arthur Holmes and continental drift |journal=[[The British Journal for the History of Science]] |volume=11 |issue=2 |pages=130–50 |doi=10.1017/S0007087400016551 |jstor=4025726 |s2cid=145405854}}
* {{Cite journal |last=Harrison |first=C.G.A. |year=2000 |title=Questions About Magnetic Lineations in the Ancient Crust of Mars |journal=[[Science (journal)|Science]] |volume=287 |issue=5453 |page=547a |doi=10.1126/science.287.5453.547a |doi-access=free}}
* {{Cite journal |last=Heezen |first=B. |year=1960 |title=The rift in the ocean floor |journal=[[Scientific American]] |volume=203 |issue=4 |pages=98–110 |bibcode=1960SciAm.203d..98H |doi=10.1038/scientificamerican1060-98}}
* {{Cite journal |last1=Heirtzler |first1=James R. |last2=Le Pichon |first2=Xavier |last3=Baron |first3=J. Gregory |year=1966 |title=Magnetic anomalies over the Reykjanes Ridge |journal=[[Deep-Sea Research]] |volume=13 |issue=3 |pages=427–32 |bibcode=1966DSRA...13..427H |doi=10.1016/0011-7471(66)91078-3}}
* {{Cite journal |last=Holmes |first=Arthur |year=1928 |title=Radioactivity and Earth movements |journal=[[Transactions of the Geological Society of Glasgow]] |volume=18 |issue=3 |pages=559–606 |doi=10.1144/transglas.18.3.559 |s2cid=122872384}}
* {{Cite journal |last=Kasting |first=James F. |year=1988 |title=Runaway and moist greenhouse atmospheres and the evolution of Earth and Venus |url=https://zenodo.org/record/1253896 |journal=Icarus |volume=74 |issue=3 |pages=472–94 |bibcode=1988Icar...74..472K |doi=10.1016/0019-1035(88)90116-9 |pmid=11538226 }}
* {{Cite journal |last=Korgen |first=Ben J. |year=1995 |title=A voice from the past: John Lyman and the plate tectonics story |journal=Oceanography |volume=8 |issue=1 |pages=19–20 |doi=10.5670/oceanog.1995.29 |doi-access=free|bibcode=1995Ocgpy...8a..19K }}
* {{Cite journal |last=Lippsett |first=Laurence |year=2001 |title=Maurice Ewing and the Lamont–Doherty Earth Observatory |url=http://www.columbia.edu/cu/alumni/Magazine/Winter2001/ewing.html |journal=Living Legacies |access-date=2008-03-04 }}
* {{Cite journal |last=Lovett |first=Richard A. |date=24 January 2006 |title=Moon Is Dragging Continents West, Scientist Says |url=http://news.nationalgeographic.com/news/2006/01/0124_060124_moon.html |journal=[[National Geographic News]] |archive-url=https://web.archive.org/web/20060207172518/http://news.nationalgeographic.com/news/2006/01/0124_060124_moon.html |archive-date=7 February 2006 }}
* {{Cite journal |last1=Lyman |first1=J. |last2=Fleming |first2=R.H. |year=1940 |title=Composition of Seawater |journal=[[Journal of Marine Research]] |volume=3 |pages=134–46}}
* {{Cite journal |last1=Mallard |first1=Claire |last2=Coltice |first2=Nicolas |last3=Seton |first3=Maria |last4=Müller |first4=R. Dietmar |last5=Tackley |first5=Paul J. |year=2016 |title=Subduction controls the distribution and fragmentation of Earth's tectonic plates |url=https://hal.archives-ouvertes.fr/hal-01355818/document |url-status=live |journal=[[Nature (journal)|Nature]] |volume=535 |issue=7610 |pages=140–43 |bibcode=2016Natur.535..140M |doi=10.1038/nature17992 |issn=0028-0836 |pmid=27309815 |s2cid=4407214 |archive-url=https://web.archive.org/web/20160924200657/https://hal.archives-ouvertes.fr/hal-01355818/document |archive-date=2016-09-24 |access-date=2016-09-15 }}
* {{Cite journal |last=Maruyama |first=Shigenori |year=1994 |title=Plume tectonics |journal=[[Journal of the Geological Society of Japan]] |volume=100 |pages=24–49 |doi=10.5575/geosoc.100.24 |doi-access=free}}
* {{Cite journal |last1=Mason |first1=Ronald G. |last2=Raff |first2=Arthur D. |year=1961 |title=Magnetic survey off the west coast of the United States between 32°N latitude and 42°N latitude |journal=[[Bulletin of the Geological Society of America]] |volume=72 |issue=8 |pages=1259–66 |bibcode=1961GSAB...72.1259M |doi=10.1130/0016-7606(1961)72[1259:MSOTWC]2.0.CO;2 |issn=0016-7606}}
* {{Cite journal |last1=McKenzie |first1=D. |last2=Parker |first2=R.L. |year=1967 |title=The North Pacific: an example of tectonics on a sphere |journal=[[Nature (journal)|Nature]] |volume=216 |issue=5122 |pages=1276–1280 |bibcode=1967Natur.216.1276M |doi=10.1038/2161276a0 |s2cid=4193218}}
* {{Cite journal |last=Moore |first=George W. |year=1973 |title=Westward Tidal Lag as the Driving Force of Plate Tectonics |journal=[[Geology (journal)|Geology]] |volume=1 |issue=3 |pages=99–100 |bibcode=1973Geo.....1...99M |doi=10.1130/0091-7613(1973)1<99:WTLATD>2.0.CO;2 |issn=0091-7613}}
* {{Cite journal |last=Morgan |first=W. Jason |year=1968 |title=Rises, Trenches, Great Faults, and Crustal Blocks |url=http://www.mantleplumes.org/WebDocuments/Morgan1968.pdf |journal=[[Journal of Geophysical Research]] |volume=73 |issue=6 |pages=1959–182 |bibcode=1968JGR....73.1959M |doi=10.1029/JB073i006p01959 }}
* {{Cite journal |last=Le Pichon |first=Xavier |date=15 June 1968 |title=Sea-floor spreading and continental drift |journal=[[Journal of Geophysical Research]] |volume=73 |issue=12 |pages=3661–97 |bibcode=1968JGR....73.3661L |doi=10.1029/JB073i012p03661}}
* {{Cite web |last1=Quilty |first1=Patrick G. |last2=Banks |first2=Maxwell R. |year=2003 |title=Samuel Warren Carey, 1911–2002 |url=http://www.science.org.au/fellows/memoirs/carey.html |archive-url=https://web.archive.org/web/20101221023449/http://science.org.au/fellows/memoirs/carey.html |archive-date=2010-12-21 |access-date=2010-06-19 |website=Biographical memoirs |publisher=[[Australian Academy of Science]] |quote=This memoir was originally published in ''Historical Records of Australian Science'' (2003) '''14''' (3). }}
* {{Cite journal |last1=Raff |first1=Arthur D. |last2=Mason |first2=Roland G. |year=1961 |title=Magnetic survey off the west coast of the United States between 40°N latitude and 52°N latitude |journal=[[Bulletin of the Geological Society of America]] |volume=72 |issue=8 |pages=1267–70 |bibcode=1961GSAB...72.1267R |doi=10.1130/0016-7606(1961)72[1267:MSOTWC]2.0.CO;2 |issn=0016-7606}}
* {{Cite journal |last=Runcorn |first=S.K. |author-link=Keith Runcorn |year=1956 |title=Paleomagnetic comparisons between Europe and North America |journal=[[Proceedings, Geological Association of Canada]] |volume=8 |issue=1088 |page=7785 |bibcode=1965RSPTA.258....1R |doi=10.1098/rsta.1965.0016 |s2cid=122416040}}
* {{Cite journal |last1=Scalera |first1=G. |last2=Lavecchia |first2=G. |name-list-style=amp |year=2006 |title=Frontiers in earth sciences: new ideas and interpretation |journal=[[Annals of Geophysics]] |volume=49 |issue=1 |doi=10.4401/ag-4406 |doi-access=free}}
* {{Cite journal |last1=Scoppola |first1=B. |last2=Boccaletti |first2=D. |last3=Bevis |first3=M. |last4=Carminati |first4=E. |last5=Doglioni |first5=C. |year=2006 |title=The westward drift of the lithosphere: A rotational drag? |journal=[[Geological Society of America Bulletin]] |volume=118 |issue=1–2 |pages=199–209 |bibcode=2006GSAB..118..199S |doi=10.1130/B25734.1}}
* {{Cite journal |last=Segev |first=A |year=2002 |title=Flood basalts, continental breakup and the dispersal of Gondwana: evidence for periodic migration of upwelling mantle flows (plumes) |journal=EGU Stephan Mueller Special Publication Series |volume=2 |pages=171–91 |bibcode=2002SMSPS...2..171S |doi=10.5194/smsps-2-171-2002 |doi-access=free}}
* {{Cite journal |last=Sleep |first=Norman H. |author-link=Norman Sleep |year=1994 |title=Martian plate tectonics |url=http://www.es.ucsc.edu/~rcoe/eart290C/Additional%20Papers/Sleep_MartianPlateTectonics_JGR94.pdf |journal=[[Journal of Geophysical Research]] |volume=99 |issue=E3 |page=5639 |bibcode=1994JGR....99.5639S |citeseerx=10.1.1.452.2751 |doi=10.1029/94JE00216 }}{{Dead link|date=October 2022 |bot=InternetArchiveBot |fix-attempted=yes }}
* {{Cite journal |last1=Soderblom |first1=Laurence A. |last2=Tomasko |first2=Martin G. |last3=Archinal |first3=Brent A. |last4=Becker |first4=Tammy L. |last5=Bushroe, Michael W. |last6=Cook, Debbie A. |last7=Doose, Lyn R. |last8=Galuszka, Donna M. |last9=Hare, Trent M. |last10=Howington-Kraus, Elpitha |last11=Karkoschka, Erich |last12=Kirk, Randolph L. |last13=Lunine, Jonathan I. |last14=McFarlane, Elisabeth A. |last15=Redding, Bonnie L. |year=2007 |title=Topography and geomorphology of the Huygens landing site on Titan |url=https://zenodo.org/record/1259323 |journal=[[Planetary and Space Science]] |volume=55 |issue=13 |pages=2015–24 |bibcode=2007P&SS...55.2015S |doi=10.1016/j.pss.2007.04.015 |author16=Rizk, Bashar |author17=Rosiek, Mark R. |author18=See, Charles |author19=Smith, Peter H. }}
* {{Cite journal |last=Spence |first=William |year=1987 |title=Slab pull and the seismotectonics of subducting lithosphere |url=http://szseminar.asu.edu/readings/Rev_Geophys_Spence_1987.pdf |journal=[[Reviews of Geophysics]] |volume=25 |issue=1 |pages=55–69 |bibcode=1987RvGeo..25...55S |doi=10.1029/RG025i001p00055 |archive-date=2016-03-03  |access-date=2010-11-22  |archive-url=https://web.archive.org/web/20160303212057/http://szseminar.asu.edu/readings/Rev_Geophys_Spence_1987.pdf }}
* {{Cite journal |last1=Spiess |first1=Fred |last2=Kuperman |first2=William |year=2003 |title=The Marine Physical Laboratory at Scripps |journal=Oceanography |volume=16 |issue=3 |pages=45–54 |doi=10.5670/oceanog.2003.30 |doi-access=free|bibcode=2003Ocgpy..16c..45S }}
* {{Cite journal |last1=Tanimoto |first1=Toshiro |last2=Lay |first2=Thorne |date=7 November 2000 |title=Mantle dynamics and seismic tomography |journal=[[Proceedings of the National Academy of Sciences]] |volume=97 |issue=23 |pages=12409–110 |bibcode=2000PNAS...9712409T |doi=10.1073/pnas.210382197 |pmc=34063 |pmid=11035784 |doi-access=free}}
* {{Cite journal |last=Thomson |first=W. |year=1863 |title=On the secular cooling of the earth |journal=Philosophical Magazine |volume=4 |issue=25 |pages=1–14 |doi=10.1080/14786446308643410}}
* {{Cite journal |last1=Torsvik |first1=Trond H. |last2=Steinberger |first2=Bernhard |last3=Gurnis |first3=Michael |last4=Gaina |first4=Carmen |year=2010 |title=Plate tectonics and net lithosphere rotation over the past 150 My |url=http://www.gps.caltech.edu/~gurnis/Papers/2010_Torsvik_etal_EPSL.pdf |journal=[[Earth and Planetary Science Letters]] |volume=291 |issue=1–4 |pages=106–12 |bibcode=2010E&PSL.291..106T |doi=10.1016/j.epsl.2009.12.055 |archive-url=https://web.archive.org/web/20110516165855/http://www.gps.caltech.edu/~gurnis/Papers/2010_Torsvik_etal_EPSL.pdf |archive-date=16 May 2011 |access-date=18 June 2010 |hdl=10852/62004 }}
* {{Cite journal |last1=Valencia |first1=Diana |last2=O'Connell |first2=Richard J. |last3=Sasselov |first3=Dimitar D |date=November 2007 |title=Inevitability of Plate Tectonics on Super-Earths |journal=[[Astrophysical Journal Letters]] |volume=670 |issue=1 |pages=L45–L48 |arxiv=0710.0699 |bibcode=2007ApJ...670L..45V |doi=10.1086/524012 |s2cid=9432267}}
* {{Cite journal |last=Van Bemmelen |first=R.W. |year=1976 |title=Plate Tectonics and the Undation Model: a comparison |journal=[[Tectonophysics (journal)|Tectonophysics]] |volume=32 |issue=3 |pages=145–182 |bibcode=1976Tectp..32..145V |doi=10.1016/0040-1951(76)90061-5}}
* {{Citation |last=Van Bemmelen |first=R.W. |title=Geodynamic Models, an evaluation and a synthesis |work=Developments in Geotectonics |volume=2 |year=1972 |place=Amsterdam |publisher=Elsevies Publ. Comp.}}
* {{Cite journal |last1=Vine |first1=F.J. |last2=Matthews |first2=D.H. |year=1963 |title=Magnetic anomalies over oceanic ridges |journal=[[Nature (journal)|Nature]] |volume=199 |issue=4897 |pages=947–949 |bibcode=1963Natur.199..947V |doi=10.1038/199947a0 |s2cid=4296143}}
* {{Cite journal |last=Wegener |first=Alfred |date=6 January 1912 |title=Die Herausbildung der Grossformen der Erdrinde (Kontinente und Ozeane), auf geophysikalischer Grundlage |url=http://epic.awi.de/Publications/Polarforsch2005_1_3.pdf |journal=Petermanns Geographische Mitteilungen |volume=63 |pages=185–95, 253–56, 305–09 |archive-url=https://web.archive.org/web/20100705081509/http://epic.awi.de/Publications/Polarforsch2005_1_3.pdf |archive-date=5 July 2010 }}
* {{Cite journal |last=Wezel |first=F.-C. |year=1988 |title=The origin and evolution of arcs |journal=[[Tectonophysics (journal)|Tectonophysics]] |volume=146 |issue=1–4 |doi=10.1016/0040-1951(88)90079-0}}
* {{Cite journal |last1=White |first1=R. |last2=McKenzie |first2=D. |year=1989 |title=Magmatism at rift zones: The generation of volcanic continental margins and flood basalts |journal=[[Journal of Geophysical Research]] |volume=94 |pages=7685–729 |bibcode=1989JGR....94.7685W |doi=10.1029/JB094iB06p07685}}
* {{Cite journal |last=Wilson |first=J.T. |date=8 June 1963 |title=Hypothesis on the Earth's behaviour |journal=[[Nature (journal)|Nature]] |volume=198 |issue=4884 |pages=849–65 |bibcode=1963Natur.198..925T |doi=10.1038/198925a0 |s2cid=28014204}}
* {{Cite journal |last=Wilson |first=J. Tuzo |date=July 1965 |title=A new class of faults and their bearing on continental drift |url=http://www.rpi.edu/~mccafr/plates/reading/wilson_1965.pdf |journal=[[Nature (journal)|Nature]] |volume=207 |issue=4995 |pages=343–47 |bibcode=1965Natur.207..343W |doi=10.1038/207343a0 |s2cid=4294401 |archive-url=https://web.archive.org/web/20100806140625/http://www.rpi.edu/~mccafr/plates/reading/wilson_1965.pdf |archive-date=August 6, 2010 }}
* {{Cite journal |last=Wilson |first=J. Tuzo |date=13 August 1966 |title=Did the Atlantic close and then re-open? |journal=[[Nature (journal)|Nature]] |volume=211 |issue=5050 |pages=676–81 |bibcode=1966Natur.211..676W |doi=10.1038/211676a0 |s2cid=4226266 |doi-access=free}}
* {{Cite web |last=Zhen Shao |first=Huang |year=1997 |title=Speed of the Continental Plates |url=http://hypertextbook.com/facts/ZhenHuang.shtml |archive-url=https://web.archive.org/web/20120211080200/http://hypertextbook.com/facts/ZhenHuang.shtml |archive-date=2012-02-11 |website=The Physics Factbook }}
* {{Cite journal |last1=Zhao |first1=Guochun |last2=Cawood |first2=Peter A. |last3=Wilde |first3=Simon A. |last4=Sun |first4=M. |year=2002 |title=Review of global 2.1–1.8 Ga orogens: implications for a pre-Rodinia supercontinent |journal=[[Earth-Science Reviews]] |volume=59 |issue=1 |pages=125–62 |bibcode=2002ESRv...59..125Z |doi=10.1016/S0012-8252(02)00073-9}}
* {{Cite journal |last1=Zhao |first1=Guochun |last2=Sun |first2=M. |last3=Wilde |first3=Simon A. |last4=Li |first4=S.Z. |year=2004 |title=A Paleo-Mesoproterozoic supercontinent: assembly, growth and breakup |url=http://www.gt-crust.ru/jour/article/view/518 |journal=Earth-Science Reviews |type=Submitted manuscript |volume=67 |issue=1 |pages=91–123 |bibcode=2004ESRv...67...91Z |doi=10.1016/j.earscirev.2004.02.003 }}
* {{Cite journal |last1=Zhong |first1=Shijie |last2=Zuber |first2=Maria T. |year=2001 |title=Degree-1 mantle convection and the crustal dichotomy on Mars |url=http://www-geodyn.mit.edu/mars.deg1.pdf |journal=[[Earth and Planetary Science Letters]] |volume=189 |issue=1–2 |pages=75–84 |bibcode=2001E&PSL.189...75Z |citeseerx=10.1.1.535.8224 |doi=10.1016/S0012-821X(01)00345-4 }}{{Dead link|date=June 2025 |bot=InternetArchiveBot |fix-attempted=yes }}
* {{Cite book |last1=Hofmeister |first1=Anne M. |title=In the Footsteps of Warren B. Ahmilton: New Ideas in Earth Science |last2=Criss |first2=Robert E. |last3=Criss |first3=Everett M. |year=2022 |editor-last=Foulger |editor-first=Gillian R. |chapter=Links of planetary energetics to moon size, orbit, and planet spin: A new mechanism for plate tectonics |pages=213–222 |doi=10.1130/2021.2553(18) |isbn=978-0-8137-2553-6 |editor-last2=Hamilton |editor-first2=Lawrence C. |editor-last3=Jurdy |editor-first3=Donna M. |editor-last4=Stein |editor-first4=Carol A. |editor-last5=Howard |editor-first5=Keith A. |editor-last6=Stein |editor-first6=Seth}}
* {{Cite journal |last=Doglioni |first=C. |year=1990 |title=The global tectonic pattern. |journal=J. Geodyn. |volume=12 |issue=1 |pages=21–38 |bibcode=1990JGeo...12...21D |doi=10.1016/0264-3707(90)90022-M}}
* {{Cite book |last=Coates |first=Robert R. |title=The Crust of the Pacific Basin |orig-date=1962 | year=2013 |isbn=978-1-118-66931-0 |series=Geophysical Monograph Series |volume=6 |pages=92–109 |chapter=Magma type and crustal structure in the Aleutian arc |bibcode=1962GMS.....6...92C |doi=10.1029/GM006p0092}}
{{refend}}

== External links ==
{{Wikibooks|Historical Geology|Plate tectonics: overview}}
{{Commons category|Plate tectonics}}
* [https://pubs.usgs.gov/gip/dynamic/dynamic.html This Dynamic Earth: The Story of Plate Tectonics]. [[USGS]].
* [https://pubs.usgs.gov/publications/text/understanding.html Understanding Plate Tectonics] {{Webarchive|url=https://web.archive.org/web/20060207093949/http://pubs.usgs.gov/publications/text/understanding.html |date=2006-02-07  }}. [[USGS]].
* [http://www.tectonic-forces.org/ An explanation of tectonic forces] {{Webarchive|url=https://web.archive.org/web/20170912092633/http://www.tectonic-forces.org/ |date=2017-09-12  }}. Example of calculations to show that Earth Rotation could be a driving force.
* [http://peterbird.name/publications/2003_PB2002/2003_PB2002.htm Bird, P. (2003); An updated digital model of plate boundaries].
* [http://snobear.colorado.edu/Markw/Mountains/03/week3.html Map of tectonic plates] {{Webarchive|url=https://web.archive.org/web/20170112143308/http://snobear.colorado.edu/Markw/Mountains/03/week3.html |date=2017-01-12  }}.
* [http://www.geology.wisc.edu/~chuck/MORVEL/ MORVEL plate velocity estimates and information]. C. DeMets, D. Argus, & R. Gordon.
* [https://ocre-geoscience.com/ocre-geomap/ Plate Model of Bird 2003 in Google Maps]
* {{In Our Time|Plate Tectonics|b008q0sp}}

'''Videos'''
* [[Khan Academy]] [https://www.youtube.com/watch?v=6EdsBabSZ4g Explanation of evidence]
* [http://www.ucmp.berkeley.edu/geology/tectonics.html 750{{nbsp}}million years of global tectonic activity]. Movie.
* [http://qz.com/577842/scientists-have-used-groundbreaking-technology-to-figure-out-how-the-earth-looked-a-billion-years-ago/ Multiple videos of plate tectonic movements] [[Quartz (publication)|Quartz]] December 31, 2015

{{Tectonic plates}}
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{{Geologic Principles}}
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[[Category:Plate tectonics| ]]
[[Category:Geodynamics]]
[[Category:Geology theories]]
[[Category:Seismology]]
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