Publication Date:
2017-04-04
Description:
We present the velocity field in Italy derived from over 300 continuous GPS stations operated in the 1998–
2009 time span. The GPS network maps the whole country with a mean inter-site distance of about 50 km
and provides a valuable source of data to study the ongoing deformation processes in the central Mediterranean.
The estimated horizontal and vertical velocity fields show major significant features and also less known
second-order kinematic features. A general uplift characterizes the whole Apennines and Alpine belts
that follow the topographic ridge, whereas the Po Plain shows a gradually increasing subsidence from
west to east. The Apennines belt displays a distinctive extension (50–80 10−9 yr−1)while compressive tectonic regimes characterize northern Sicily, eastern Alps and the northeast front of the northern Apennines
(25–50 10−9 yr−1). Second-order deformation patterns, on large scale wavelength (~100 km) have been
detected on the accretionary prism of central and southern Apennines that are highly correlated with
other geophysical data (Vp anomalies, seismic anisotropy, etc.) and related to deep rooted sections (70–
100 km), marked by different subduction regimes. Apparently at this scale-length the observed deformations
are governed by the lithosphere as a whole. We interpret these deformations as a result of different subduction
mechanisms, such as variations of the subduction rollback velocity affecting different segments of the subduction
zone and/or to mantle flows in proximity of the slab edges. Further south, in central-southern Sicily, we detect a
contraction of (−1.1±0.2) mm/yr that probably accommodates part of the Africa–Eurasia convergence on the
outer thrust front of the Apennines–Maghrebides belt. This hypothesis agrees with an independent analysis of
the seismicity associated to the Sicilian Basal Thrust, thought to be still active. The ITRF2005 estimates of the
new GPS velocity field are available also in SINEX format as supplementary file S1.
Description:
Published
Description:
230-241
Description:
1.9. Rete GPS nazionale
Description:
3.3. Geodinamica e struttura dell'interno della Terra
Description:
JCR Journal
Description:
restricted
Keywords:
GPS velocity field
;
Apennines
;
Alps
;
Adria
;
Plate kinematics
;
Subduction zone
;
04. Solid Earth::04.03. Geodesy::04.03.99. General or miscellaneous
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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