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| Titel |
Three-dimensional thermal structure of subduction zones: effects of obliquity and curvature |
| VerfasserIn |
A. K. Bengtson, P. E. Keken |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1869-9510
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| Digitales Dokument |
URL |
| Erschienen |
In: Solid Earth ; 3, no. 2 ; Nr. 3, no. 2 (2012-11-22), S.365-373 |
| Datensatznummer |
250000994
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| Publikation (Nr.) |
 copernicus.org/se-3-365-2012.pdf |
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| Zusammenfassung |
| Quantifying the precise thermal structure of subduction zones is essential
for understanding the nature of metamorphic dehydration reactions, arc
volcanism, and intermediate depth seismicity. High resolution
two-dimensional (2-D) models have shown that the rheology of the mantle wedge
plays a critical role and establishes strong temperature gradients in the
slab. The influence of three-dimensional (3-D) subduction zone geometry on
thermal structure is however not yet well characterized. A common assumption
for 2-D models is that the cross-section is taken normal to the strike of the
trench with a corresponding velocity reduction in the case of oblique
subduction, rather than taken parallel to velocity. A comparison between a
full 3-D Cartesian model with oblique subduction and selected 2-D
cross-sections demonstrates that the trench-normal cross-section provides a
better reproduction of the slab thermal structure than the velocity-parallel
cross-section. An exception is found in the case of a strongly curved
trench, such as in the Marianas, where strong 3-D flow in the mantle wedge is
generated. In this case it is shown that the full 3-D model should be
evaluated for an accurate prediction of the slab thermal structure. The
models demonstrate that the use of a dynamic slab and wedge, separated by a
kinematic boundary, yields good results for describing slab velocities in 3-D. |
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