Publication Date:
2020-10-26
Description:
This paper presents a velocity model of the Italian (central Mediterranean) lithosphere in unprecedented detail. The model is derived by inverting a set of 166,000 Pg and Pn seismic wave arrival times, restricted to the highest-quality data
available. The tomographic images reveal the geometry of the subduction-collision system
between the European, Adriatic, and Tyrrhenian plates, over a larger volume and with finer resolution than previous studies. We find two arcs of low-Vp anomalies running along the Alps and the Apennines, describing the collision zones of underthrusting continental lithospheres. Our results suggest that in the Apennines, a significant portion of the crust has been subducted below the mountain belt. From the velocity model we can also infer thermal softening of the crustal wedge above the subducting Adriatic plate. In the Tyrrhenian back-arc region, strong and extensive low-Vp anomalies depict upwelling asthenospheric material. The tomographic images also allow us to trace the boundary between the Adriatic and the Tyrrhenian plates at Moho depth, revealing
some tears in the Adriatic-Ionian subducting lithosphere. The complex lithospheric
structure described by this study is the result of a long evolution; the heterogeneities of
continental margins, lithospheric underthrusting, and plate indentation have led to subduction variations, slab tears, and asthenospheric upwelling at the present day.
The high-resolution model provided here greatly improves our understanding of the
central Mediterranean’s structural puzzle. The results of this study can also shed light on the evolution of other regions experiencing both oceanic and continental subduction.
Description:
Published
Description:
B05305
Description:
3.3. Geodinamica e struttura dell'interno della Terra
Description:
JCR Journal
Description:
open
Keywords:
lithosphere
;
crust
;
italy
;
plates
;
subduction
;
europe
;
seismicity
;
adria
;
tyrrhenian
;
boundary
;
04. Solid Earth::04.06. Seismology::04.06.07. Tomography and anisotropy
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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