Publication Date:
2017-04-04
Description:
We document quantitatively observations of quasi-Love waves obtained at permanent (Italian National Seismic Network) and temporary seismic stations deployed in Italy between 2003 and 2006 (Retreat, CAT/SCAN projects). We analyzed large earthquakes with source parameters that favor quasi-Love wave generation within this time-span, including the Sumatra–Andaman earthquake of 12/26/04. The presence or the absence of the quasi-Love phase is compared to the smoothed anisotropic pattern defined by the numerous SKS splitting measurements obtained in peninsular Italy, and to the Italian upper mantle structure as defined by seismic tomography. The large-scale anisotropic features, responsible for shear-wave splitting and documented also by Pn and surface-wave anisotropy, generally display the correct geometry to explain the scattered quasi-Love waves. Quasi-Love observations do not demand a tilted-axis anisotropic geometry. We argue instead for anisotropy with laterally-variable horizontal symmetry axis in the upper mantle below the Italian peninsula.
Description:
Published
Description:
26-38
Description:
1T. Geodinamica e interno della Terra
Description:
JCR Journal
Description:
restricted
Keywords:
Seismic anisotropy
;
Quasi-Love
;
Italy
;
04. Solid Earth::04.01. Earth Interior::04.01.02. Geological and geophysical evidences of deep processes
;
04. Solid Earth::04.06. Seismology::04.06.07. Tomography and anisotropy
;
04. Solid Earth::04.07. Tectonophysics::04.07.06. Subduction related processes
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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