Changes

===Solar system analogues===

===Solar system analogues===

All the rocky planets in the solar system except Earth are generally believed to be in the stagnant lid geodynamic regime.<ref name=Reese_etal_1998 /><ref name=Moresi_solomatov_1998 /> [[Geodynamics of Mars|Mars]] and particularly [[Geodynamics of Venus|Venus]] have evidence of prior resurfacing events, but appear to be tectonically quiescent today. Geodynamic inferences about solar system planets have been extrapolated to exoplanets in order to constrain what kind of geodynamic regimes can be expected given a set of physical criterion such as planetary radius, presence of surface water, and insolation. In particular, the planet Venus has been intensely studied due to its general physical similarities to Earth yet completely different geodynamic regime. Proposed explanations include a lack of surface water,<ref name=Moresi_solomatov_1998 /> the lack of a magnetic geodynamo,<ref name=VanSummeren_etal_2013>{{cite journal|last1=Van Summeren|first1=J.|last2=Gaidos|first2=E.|last3=Conrad|first3=C.P.|title=Magnetodynamo lifetimes for rocky, Earth-mass exoplanets with contrasting mantle convection regimes|journal=Journal of Geophysical Research: Planets|date=16 May 2013|volume=118|pages=938–951|doi=10.1002/jgre.20077|url=http://onlinelibrary.wiley.com/doi/10.1002/jgre.20077/abstract?deniedAccessCustomisedMessage=&userIsAuthenticated=false|accessdate=10 October 2014}}</ref> or large-scale evacuation of interior heat shortly after planetary coalescence.<ref name=Reese_etal_1998 />

All the rocky planets in the solar system except Earth are generally believed to be in the stagnant lid geodynamic regime.<ref name=Reese_etal_1998 /><ref name=Moresi_solomatov_1998 /> [[Geodynamics of Mars|Mars]] and particularly [[Geodynamics of Venus|Venus]] have evidence of prior resurfacing events, but appear to be tectonically quiescent today. Geodynamic inferences about solar system planets have been extrapolated to exoplanets in order to constrain what kind of geodynamic regimes can be expected given a set of physical criterion such as planetary radius, presence of surface water, and insolation. In particular, the planet Venus has been intensely studied due to its general physical similarities to Earth yet completely different geodynamic regime. Proposed explanations include a lack of surface water,<ref name=Moresi_solomatov_1998 /> the lack of a magnetic geodynamo,<ref name=VanSummeren_etal_2013>Van Summeren, J.; Gaidos, E.; Conrad, C.P. (16 May 2013). "Magnetodynamo lifetimes for rocky, Earth-mass exoplanets with contrasting mantle convection regimes". Journal of Geophysical Research: Planets 118: 938–951. doi:10.1002/jgre.20077. Retrieved 10 October 2014.</ref> or large-scale evacuation of interior heat shortly after planetary coalescence.<ref name=Reese_etal_1998 />

Another source of insight within our solar system is the history of the planet Earth, which may have had several episodes of stagnant lid geodynamics during its history.<ref name=Stern_2008>{{cite journal|last1=Stern|first1=R.J.|title=Modern-style plate tectonics began in neoproterozoic time: an alternative interpretation of Earth's tectonic history|journal=Geological Society of America Special Paper|date=14 August 2007|volume=440|pages=1–16| doi=10.1130/2008.2440(13)|url=http://specialpapers.gsapubs.org/content/440/265.abstract|accessdate=10 October 2014}}</ref> These stagnant-lid periods were not necessarily planet-wide; when supercontinents such as Gondwanaland existed, their presence may have shut off plate motion over large expanses of the Earth’s surface until mantle heat buildup underneath the superplate was sufficient to break them apart.<ref name=Ernst_2009>{{cite journal|last1=Ernst|first1=W.G.|title=Archean plate tectonics, rise of Proterozoic supercontinentality and onset of regional, episodic stagnant-lid behavior|journal=Gondwana Research|date=13 July 2008|volume=15|pages=243–253|doi=10.1016/j.gr.2008.06.010|url=http://www.sciencedirect.com/science/article/pii/S1342937X0800107X|accessdate=10 October 2014}}</ref>

Another source of insight within our solar system is the history of the planet Earth, which may have had several episodes of stagnant lid geodynamics during its history.<ref name=Stern_2008>{{cite journal|last1=Stern|first1=R.J.|title=Modern-style plate tectonics began in neoproterozoic time: an alternative interpretation of Earth's tectonic history|journal=Geological Society of America Special Paper|date=14 August 2007|volume=440|pages=1–16| doi=10.1130/2008.2440(13)|url=http://specialpapers.gsapubs.org/content/440/265.abstract|accessdate=10 October 2014}}</ref> These stagnant-lid periods were not necessarily planet-wide; when supercontinents such as Gondwanaland existed, their presence may have shut off plate motion over large expanses of the Earth’s surface until mantle heat buildup underneath the superplate was sufficient to break them apart.<ref name=Ernst_2009>{{cite journal|last1=Ernst|first1=W.G.|title=Archean plate tectonics, rise of Proterozoic supercontinentality and onset of regional, episodic stagnant-lid behavior|journal=Gondwana Research|date=13 July 2008|volume=15|pages=243–253|doi=10.1016/j.gr.2008.06.010|url=http://www.sciencedirect.com/science/article/pii/S1342937X0800107X|accessdate=10 October 2014}}</ref>