Publication Date:
2020-11-25
Description:
We present crustal deformation results from a geodetic experiment (Retreating-Trench,
Extension, and Accretion Tectonics (RETREAT)) focused on the northern Apennines
orogen in Italy. The experiment centers on 33 benchmarks measured with GPS annually or
more frequently between 2003 and 2007, supplemented by data from an additional older
set of 6 campaign observations from stations in northern Croatia, and 187 continuous GPS
stations within and around northern Italy. In an attempt to achieve the best possible
estimates for rates and their uncertainties, we estimate and filter common mode signals and
noise components using the continuous stations and apply these corrections to the entire
data set, including the more temporally limited campaign time series. The filtered
coordinate time series data are used to estimate site velocity. We also estimate spatially
variable seasonal site motions for stations with sufficient data. The RMS scatter of residual
time series are generally near 1 mm and 4 mm, horizontal and vertical, respectively, for
continuous and most of the new campaign stations, but scatter is slightly higher for some of
the older campaign data. Velocity uncertainties are below 1 mm/yr for all but one of the
stations. Maximum rates of site motion within the orogen exceed 3 mm/yr (directed NE)
relative to stable Eurasia. This motion is accommodated by extension within the
southwestern and central portions of the orogen, and shortening across the foreland thrust
belt to the northeast of the range. The data set is consistent with contemporaneous
extension and shortening at nearly equal rates. The northern Apennines block moves
northeast faster than the Northern Adria microplate. Convergence between the Northern
Apennines block and the Northern Adria microplate is accommodated across a narrow
zone that coincides with the northeastern Apennines range front. Extension occurs directly
above an intact vertically dipping slab inferred by previous authors from seismic
tomography. The observed crustal deformation is consistent with a buried dislocation
model for crustal faulting, but associations between crustal motion and seismically imaged
mantle structure may also provide new insights on mantle dynamics.
Description:
Published
Description:
B04408
Description:
3.2. Tettonica attiva
Description:
JCR Journal
Description:
restricted
Keywords:
GPS, northern Apennines, retreat, Italy
;
04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformations
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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