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| Titel |
Mantle structure beneath the Alboran Sea from shear wave splitting |
| VerfasserIn |
L. Alpert, T. W. Becker, M. Miller, A. Allam |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250060545
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| Zusammenfassung |
| We evaluate global circulation models in the context of seismic anistropy as inferred
from SKS/SKKS splitting observations for the Alboran Sea. Using instantaneous
velocity fields from 3-D flow models with additional mantle density, we calculate the
predicted anisotropy, fast polarization direction (FPD), and SKS delay times in order to
explain the complex tectonic and geologic history of the Alboran Sea region. Slab
rollback, delamination, and convective removal processes have been invoked to explain
the synorogenic extension and recently published splitting measurements show
north-east trending FPD across the Iberian margin with a rotation to the southeast that
follows the curve of the Gibraltar arc, suggested as supporting west-directed slab
rollback. Our new measurements from 39 stations in southern Spain and Morocco
substantiate published estimates in southern Spain, but we find a rotation in azimuth
and reduced delay times across the High Atlas Mountains. Our preliminary results
show that density models which include a ENE trending structure which curves
southward around the Gibraltar arc, plus a stiff continental keel beneath Africa,
produce splitting orientations and delay times that best match the observations. |
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