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| Titel |
Numerical Modeling of Mantle Convection with Heat-pipe Melt Transport |
| VerfasserIn |
Sebastian Prinz, Ana-Catalina Plesa, Nicola Tosi, Doris Breuer |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250113803
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| Publikation (Nr.) |
 EGU/EGU2015-14927.pdf |
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| Zusammenfassung |
| During the early evolution of terrestrial bodies, a large amount of mantle melting is
expected to affect significantly the energy budget of the interior through heat transport
by volcanism. Partial melt, generated when the mantle temperature exceeds the
solidus, can propagate to the surface through dikes, thereby advecting upwards a large
amount of heat. This so-called heat-pipe mechanism is an effective way to transport
thermal energy from the meltregion to the planetary surface. Indeed, recent studies
suggest that this mechanism may have shaped the Earth’s earliest evolution by
controlling interior heat loss until the onset of plate tectonics [1]. Furthermore,
heat-piping is likely the primary mechanism through which Jupiter’s moon Io loses its
tidally generated heat, leading to massive volcanism able to cause a present-day
heat-flux about 40 times higher than the Earth’s average heat-flux [2]. However,
despite its obvious importance, heat-piping is often neglected in mantle convection
models of terrestrial planets because of its additional complexity and vaguely defined
parameterization.
In this study, adopting the approach of [1] we model mantle convection in a generic
stagnant lid planet and study heat-piping effects in a systematic way. Assuming that melt is
instantaneously extracted to the surface and melting regions are refilled by downward
advection of cold mantle material in order to ensure mass conservation, we investigate the
influence of heat-pipes on the mantle temperature and stagnant lid thickness using the
numerical code Gaia [3]. To this end, we run a large set of simulations in 2D Cartesian
geometry spanning a wide parameter space. Our results are consistent with [1] and show that
in systems with strongly temperature-dependent viscosity the heat-pipe mechanism sets in at
a Rayleigh number Ra ~ 2 x 107. Upon increasing Ra up to ~ 6 x 107, we observe a
systematic decrease of the average mantle temperature accompanied by an increase of
the lid thickness compared to cases where heat-piping effects are neglected. By
increasing further the Rayleigh number, the effect levels off, eventually leading to
an average mantle temperature ~ 10% smaller and a stagnant lid almost twice as
thick.
References
[1] Moore, W. B., and A. G. Webb, Nature, 2013;
[2] O’Reilly, T. C., and G. F. Davies, Geophys. Res. Lett., 1981;
[3] Hüttig C. et al., PEPI, 2013. |
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