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| Titel |
Towards understanding how surface life can affect interior geological processes: a non-equilibrium thermodynamics approach |
| VerfasserIn |
J. G. Dyke, F. Gans, A. Kleidon |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
2190-4979
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| Digitales Dokument |
URL |
| Erschienen |
In: Earth System Dynamics ; 2, no. 1 ; Nr. 2, no. 1 (2011-06-28), S.139-160 |
| Datensatznummer |
250000465
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| Publikation (Nr.) |
 copernicus.org/esd-2-139-2011.pdf |
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| Zusammenfassung |
| Life has significantly altered the Earth's atmosphere, oceans and crust. To
what extent has it also affected interior geological processes? To address
this question, three models of geological processes are formulated: mantle
convection, continental crust uplift and erosion and oceanic crust recycling.
These processes are characterised as non-equilibrium thermodynamic systems.
Their states of disequilibrium are maintained by the power generated from the
dissipation of energy from the interior of the Earth. Altering the thickness
of continental crust via weathering and erosion affects the upper mantle
temperature which leads to changes in rates of oceanic crust recycling and
consequently rates of outgassing of carbon dioxide into the atmosphere.
Estimates for the power generated by various elements in the Earth system are
shown. This includes, inter alia, surface life generation of 264 TW of
power, much greater than those of geological processes such as mantle
convection at 12 TW. This high power results from life's ability to harvest
energy directly from the sun. Life need only utilise a small fraction of the
generated free chemical energy for geochemical transformations at the
surface, such as affecting rates of weathering and erosion of continental
rocks, in order to affect interior, geological processes. Consequently when
assessing the effects of life on Earth, and potentially any planet with a
significant biosphere, dynamical models may be required that better capture
the coupled nature of biologically-mediated surface and interior processes. |
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