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| Titel |
Crustal Thickness in the Ibero-Maghrebian region I: Northern Morocco |
| VerfasserIn |
F. Mancilla, D. Stich, J. Morales, J. Julià, J. Díaz, A. Pazos, D. Córdoba, J. A. Pulgar, P. Ibarra, M. Harnafi, F. Gonzalez-Lodeiro |
| 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 |
250062707
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| Zusammenfassung |
| During the TopoIberia experiment, a total of 26 seismic broadband stations were recording in
northern Morocco, providing for the first time extended regional coverage for investigating
structure and seismotectonics of the southern branch of the Betic-Rif arc, its foreland and the
Atlas domain. Here, we analyze P-to-S converted waves in teleseismic receiver functions to
infer gross crustal properties as thickness and Vp/Vs ratio. Strong lateral variations of the
crustal thickness are observed throughout the region. Crustal thicknesses vary between 22 km
and 44 km and display a simple geographic pattern that divides the study area into
three domains: entire northwestern Morocco underlain by a thickened crust with
crustal thicknesses between 35 km and 44 km; northeastern Morocco affected by
significant crustal thinning, with crustal thicknesses ranging from 22 km to 30 km, with
the shallowest Moho along the Mediterranean coast; and an extended domain of
27-34 km thick crust, further south which includes the Atlas domain and its foreland
regions. Vp/Vs ratios show normal values of ~ 1.75 for most stations except for
the Atlas domain, where several stations give low Vp/Vs ratios around 1.71. The
very sharp transition from thick crust in northwestern Morocco to thin crust in
northeastern Morocco is attributed to regional geodynamics possibly the realm of
present-day subcrustal dynamics in the final stage of western Mediterranean subduction.
Crustal thicknesses just slightly above 30km in the southern domain are intriguing,
showing that high topography in this region is not isostatically compensated at crustal
level. |
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