Publication Date:
2017-04-04
Description:
Adria is a small region surrounded by three mountain belts: the Alps, the Apennines,
and the Dinarides, built up by long evolution of subduction and collisional systems. We
present 253 shear wave splitting measurements obtained by studying more than 100
teleseismic events for 12 stations. SKS splitting measurements show 3-D complexity and
quite strong upper mantle deformation. We carefully analyzed results in terms of back
azimuthal coverage and interpret measurements as related to Adria rotation and to
subductions evolution. In the northern part of Adria, the anisotropy pattern follows the
arcuate shape of the Alps; the same pattern, parallel to the mountains, occurs along the
Apennines, but fast directions show a sudden change in the Adria foreland. This lateral
variation has been analyzed to isolate a distinct Adria mantle anisotropic pattern, which is identified as NE-SW fast direction along the western microplate boundary and as N-S fast direction at Trieste. This pattern might be induced by drag effect of the counterclockwise rotation of Adria lithosphere that behaves as an independent microplate as identified by GPS data. Our measurements suggest that the geodynamic process that generated the Alps is more efficient deforming a larger volume of mantle than its Apennine counterpart. Moreover, the mantle circulation we hypothesize looking at the regional-scale patterns of anisotropy requires the existence of an escape route beneath the Alps-Apennines transition, through which the mantle flows and feed circulation in the Tyrrhenian mantle system as suggested by previous geodynamic models and as seen by some tomographic studies.
Description:
Published
Description:
5814–5826
Description:
3.3. Geodinamica e struttura dell'interno della Terra
Description:
JCR Journal
Description:
restricted
Keywords:
Seismic Anisotropy
;
Adriatic region
;
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
;
05. General::05.02. Data dissemination::05.02.02. Seismological data
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Permalink
