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Why does plate tectonics only occur on Earth ?

Physics Education 01/2008; DOI: 10.1088/0031-9120/43/2/002
Source: OAI

ABSTRACT Plate tectonics governs the topography and motions of the surface of Earth,
and the loss of heat from Earth’s interior, but appears to be found uniquely on
Earth in the Solar System. Why does plate tectonics occur only on Earth?
This is one of the major questions in earth and planetary sciences research,
and raises a wide range of related questions: has plate tectonics ever occurred
on other planets in the past? How did plate tectonics start on Earth? Will it
ever end? In the absence of plate tectonics, how do planets lose their heat?
This article provides a brief introduction to the ways in which planets lose
their heat and discusses our current understanding of plate tectonics and the
challenges that lie ahead.

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    ABSTRACT: Plate tectonics is the horizontal motion of Earth’s thermal boundary layer (lithosphere) over the convecting mantle (asthenosphere) and is mostly driven by lithosphere sinking in subduction zones. Plate tectonics is an outstanding example of a self organizing, far from equilibrium complex system (SOFFECS), driven by the negative buoyancy of the thermal boundary layer and controlled by dissipation in the bending lithosphere and viscous mantle. Plate tectonics is an unusual way for a silicate planet to lose heat, as it exists on only one of the large five silicate bodies in the inner solar system. It is not known when this mode of tectonic activity and heat loss began on Earth. All silicate planets probably experienced a short-lived magma ocean stage. After this solidified, stagnant lid behavior is the common mode of planetary heat loss, with interior heat being lost by delamination and “hot spot” volcanism and shallow intrusions. Decompression melting in the hotter early Earth generated a different lithosphere than today, with thicker oceanic crust and thinner mantle lithosphere; such lithosphere would take much longer than at present to become negatively buoyant, suggesting that plate tectonics on the early Earth occurred sporadically if at all. Plate tectonics became sustainable (the modern style) when Earth cooled sufficiently that decompression melting beneath spreading ridges made thin oceanic crust, allowing oceanic lithosphere to become negatively buoyant after a few tens of millions of years. Ultimately the question of when plate tectonics began must be answered by information retrieved from the geologic record. Criteria for the operation of plate tectonics includes ophiolites, blueschist and ultra-high pressure metamorphic belts, eclogites, passive margins, transform faults, paleomagnetic demonstration of different motions of different cratons, and the presence of diagnostic geochemical and isotopic indicators in igneous rocks. This record must be interpreted individually; I interpret the record to indicate a progression of tectonic styles from active Archean tectonics and magmatism to something similar to plate tectonics at ∼1.9 Ga to sustained, modern style plate tectonics with deep subduction—and powerful slab pull—beginning in Neoproterozoic time.
    Chinese Science Bulletin 52(5):578-591. · 1.37 Impact Factor
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