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| Titel |
SKS splitting beneath the Pyrenees domain: an insight on the upper mantle deformation from central Iberia to French Massif Central |
| VerfasserIn |
Mickael Bonnin, Sébastien Chevrot, Ianis Gaudot, Méric Haugmard |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250128240
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| Publikation (Nr.) |
 EGU/EGU2016-8211.pdf |
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| Zusammenfassung |
| We performed shear-wave splitting analysis for 270 permanent (French RLPB, CEA and
Catalan) and temporary (PyrOPE and IberArray) broadband stations around the
Pyrenees range. These measurements considerably enhance the spatial resolution and
regional extent of seismic anisotropy pattern in that region. In particular, we determine
the small-scale variations of splitting parameters φ and δt along three dense
(5 km inter-station spacing) transects crossing the western, central and eastern
Pyrenees.
The anisotropy pattern in the Pyrenees is in good agreement with those in previous
studies, with relatively constant N100∘ E directions of polarization of the fast waves and
delay times around 1 s. However, the new stations from the PyrOPE experiment installed in
the Aquitaine basin indicate a sharp transition both in directions (from N100∘ E to ∼
N60∘ E) and delay times (from 1 s to ∼ 0.5 s) just north of the North Pyrenean Fault.
This could indicate the presence of the Iberian lithospheric "slab" beneath the North Pyrenean
Zone. This transition also suggests that the main contribution to anisotropy is located inside
the lithosphere.
Further East, the analysis of the French permanent broadband stations complete the
anisotropy map beneath western Alps. These new observations, especially in Savoie, confirm
the overall N-80∘ E to N40∘ E smooth rotation of the directions of polarization following
the curvature of the belt. |
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