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| Titel |
Establishing a relationship between S-wave velocity, thermal gradient and thermal conductivity for the Iberian Peninsula and surrounding areas |
| VerfasserIn |
Juvenal Andrés, Ignacio Marzán, Puy Ayarza, David Martí, Imma Palomeras, Ramon Carbonell |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250141217
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| Publikation (Nr.) |
 EGU/EGU2017-4699.pdf |
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| Zusammenfassung |
| Thermal conductivity determine the rate of heat transport by conduction from the lithosphere
to the surface. Heat flow in the surface is related to the thermal gradient and thermal
conductivity by the Fourier Law,
(q = − kdT∕dy),
where k denotes thermal conductivity and dT/dy denotes thermal gradient. When modelling
thermal data, k is usually given as a fixed value in the range of (2.5 to 5 W m−1 K−1), where
2.5 W m−1 K−1 and 3.2 W m−1 K−1 are the typical values assigned to the crust and mantle
respectively. Measurements of k are restricted to shallow layers of the crust, are discrete, and
often do not illustrate correctly its depth distribution. Here we present a new methodology
to estimate a bulk average k from 3D S-wave velocity models (Vs) and thermal
gradient maps. We found linear relationships between Vs and thermal gradient
that are used along with known mean heat flux values to depict k values, as Vs are
strongly influenced by temperature. The methodology is capable of discriminate
between different tectonic settings and is sensitive to inclusion of upper mantle in
calculations. Furthermore, it is clearly sensitive to areas where thermal stability
has not been achieved. From the estimated k values and the geothermal gradient
map we have derived a full regional heat flow map for the Iberian Peninsula and
surrounding offshore areas. Our results provide a new tool to calculate k and heat flow at
regional scales, and open a new window for more accurate lithospheric thermal
modelling.
(Research supports: CGL2014-56548-P, 2009-SGR-1595, CGL2013-47412-C2-1-P) |
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