Publication Date:
2017-04-04
Description:
In the Apennines subduction (Italy), earthquakes mainly occur within overriding
plate, along the chain axis. The events concentrate in the upper 15 km of the crust above the
mantle wedge and focal solutions indicate normal faulting. In the foreland, the seismogenic
volume affects the upper 35 km of the crust. Focal solutions indicate prevailing reverse faulting
in the northern foreland and strike-slip faulting in the southern one. The deepening of the
seismogenic volume from the chain axis to the foreland follows the deepening of the Moho and
isotherms. The seismicity above the mantle wedge is associated with uplift of the chain axial
zone, volcanism, high CO2 flux, and extension. The upward pushing of the asthenospheric mantle
and the mantle-derived, CO2-rich fluids trapped within the crust below the chain axis causes this
seismicity. All these features indicate that the axial zone of Apennines is affected by early rifting
processes. In northern Italy, the widespread and deeper seismicity in the foreland reflects active
accretion processes. In the southern foreland, the observed dextral strike-slip faulting and the lack
of reverse focal solutions suggest that accretion processes are not active at present. In our
interpretation of the Apennines subduction, the shallower seismicity of the overriding plate is due
to the dynamics (uprising and eastward migration) of the asthenospheric wedge.
Description:
Submitted
Description:
open
Keywords:
Apennines
;
crustal seismicity
;
rifting
;
subduction
;
fluids
;
geodynamics
;
04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
;
04. Solid Earth::04.07. Tectonophysics::04.07.04. Plate boundaries, motion, and tectonics
;
04. Solid Earth::04.07. Tectonophysics::04.07.06. Subduction related processes
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
manuscript
Format:
2459547 bytes
Format:
application/pdf
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