Changes

===Plate tectonics===

===Plate tectonics===

The mantle of a planet with plate tectonics has driving forces that exceed the [[yield strength]] of the brittle lithosphere, causing the lithosphere to fracture into plates that move relative to each other.<ref name="O'Neill_Lenardic" /><ref name=Valencia_etal /> A critical element of the plate tectonic system is these lithospheric plates become negatively buoyant at some point in their evolution, sinking into the mantle. The surface mass deficit is balanced by new plate being formed elsewhere through upwelling [[mantle plumes]]. Plate tectonics is an efficient method of heat transfer from the interior of the planet to the surface. Earth is the only planet plate tectonics is known to occur on,<ref name=Korenaga_2010 /> although evidence has been presented for [[Jupiter (planet)|Jupiter's]] moon [[Europa (moon)|Europa]] undergoing a form of plate tectonics analogous to Earth's.<ref name=Katterhorn_Prockter>{{cite journal|last1=Katterhorn|first1=Simon|last2=Prockter|first2=Louise|title=Evidence for subduction in the ice shell of Europa|journal=Nature Geoscience|date=September 7, 2014|volume=7|pages=762–767|doi=10.1038/ngeo2245|url=http://www.nature.com/ngeo/journal/v7/n10/full/ngeo2245.html|accessdate=13 November 2014}}</ref>

The mantle of a planet with plate tectonics has driving forces that exceed the [[yield strength]] of the brittle lithosphere, causing the lithosphere to fracture into plates that move relative to each other.<ref name="O'Neill_Lenardic" /><ref name=Valencia_etal /> A critical element of the plate tectonic system is these lithospheric plates become negatively buoyant at some point in their evolution, sinking into the mantle. The surface mass deficit is balanced by new plate being formed elsewhere through upwelling [[mantle plumes]]. Plate tectonics is an efficient method of heat transfer from the interior of the planet to the surface. Earth is the only planet plate tectonics is known to occur on,<ref name=Korenaga_2010 /> although evidence has been presented for [[Jupiter (planet)|Jupiter's]] moon [[Europa (moon)|Europa]] undergoing a form of plate tectonics analogous to Earth's.<ref name=Katterhorn_Prockter>Katterhorn, Simon; Prockter, Louise (September 7, 2014). "Evidence for subduction in the ice shell of Europa". Nature Geoscience 7: 762–767. doi:10.1038/ngeo2245. Retrieved 13 November 2014.</ref>

===Stagnant lid===

===Stagnant lid===