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| Titel |
How large are present-day heat flow variations across Mars' surface? |
| VerfasserIn |
Ana-Catalina Plesa, Nicola Tosi, Matthias Grott, 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 |
250101237
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| Publikation (Nr.) |
 EGU/EGU2015-343.pdf |
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| Zusammenfassung |
| The upcoming InSight (Interior exploration using Seismic Investigations, Geodesy
and Heat Transport) mission, to be launched in 2016, will carry the first in-situ
Martian heat flow measurement and provide an important baseline to constrain
the present-day heat budget of the planet and, in turn, the thermal and chemical
evolution of its interior. Currently, the Earth and the Moon are the only bodies on which
in-situ surface heat flow measurements have been performed. Here, strong spatial
variations of the surface heat flow are primarily caused by plate tectonics and the
heterogeneous distribution of heat producing elements over the surface (e.g., the
so-called Procellarum KREEP Terrane PKT on the lunar nearside). In the absence
of plate-tectonics and large-scale geochemical anomalies, on Mars, surface heat
flow is expected to vary less with geological location, being mainly influenced by
variations in the thickness and HPE content of the crust [1], and by mantle plumes
[2].
We have tested this assumption by running thermal evolution models for Mars in 3D
spherical geometry, using the mantle convection code Gaia [3]. In our calculations, we
employ a crust of fixed thickness with a north-south dichotomy in crustal thickness, a low
conductivity compared to the mantle and enriched in radiogenic heat producing elements.
Our results show that including compressibility effects, phase transitions and different core
sizes, surface heat flow variations are mainly dominated by the crust contribution, unless the
mantle viscosity increases more than three orders of magnitude with depth. In the latter case,
heat flow variations due to mantle upwellings are ~ 8 mW/m2 relative to surface average and
remain confined to limited surface regions. Both surface heat flow variations on
Mars obtained from numerical models and the heat flow measurement planned
for the InSight mission will permit to address the question of a possible plume
underneath Elysium and also to test the feasibility of present-day volcanism on
Mars.
[1] B.ÂC. Hahn et al., GRL, 2011.
[2] W.ÂS. Kiefer and Q. Li, GRL, 2009.
[3] C. Hüttig and K. Stemmer, PEPI, 2008. |
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