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| Titel |
Lithosphere and Asthenosphere Structure of the Western Mediterranean and Northwest Africa from Rayleigh Wave tomography and Ps Receiver Functions |
| VerfasserIn |
Imma Palomeras, Sally Thurner, Alan Levander, Maximiliano Bezada, Antonio Villaseñor, Eugene Humphreys, Ramon Carbonell, Josep Gallart |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250083257
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| Zusammenfassung |
| Since Cenozoic times the Western Mediterranean has been affected by complex
subduction and slab rollback, during African-European convergence. The deformed
region occupies a wide area from the Atlas mountains in northwest Africa to the
southern Iberian Massif in Spain. Evolutionary models of the Western Mediterranean
invoke extensive slab rollback and compression, as well as likely upper mantle
delamination/convective drip scenarios during formation of the Alboran domain, the
Betics, Rif, and Atlas Mountains. We report on a multidisciplinary, international
investigation of the Alboran System and surrounding areas. In this study we have
analyzed teleseismic data from the roughly 240 temporary and permanent broadband
seismographs operated in this region by more than a dozen different cooperating research
groups.
Here we present combined results from Rayleigh wave tomography and Ps
receiver functions. Receiver functions were made in 3 frequency bands (2 Hz, 1 Hz,
0.5 Hz) using iterative time-domain and water-level frequency-domain methods.
We measured Rayleigh phase velocities using the two-plane-wave method and
finite-frequency kernels to remove complications due to multi-pathing and to improve lateral
resolution, respectively. The resulting 3D shear velocity model was used to create 3D
image volumes of the Ps receiver functions. The RF and tomography images are
consistent with one another and withteleseismic body wave tomography (Bezada et al.,
submitted)
Our results show high velocities from ~70 km to 230 km depth in an elliptical area just
west of the Gibraltar straits which is interpreted as a near vertical slab beneath the Alboran
Domain and the adjacent Spanish continental margin. The surface wave results map out the
top of a 600+ km deep nearly vertical slab seen in the P body wave tomography. The RF
images suggest that the top of this slab is still attached to the Alboran domain Moho beneath
Gibraltar, a complex region where lower crustal velocities ( |
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