Publication Date:
2017-04-03
Description:
We investigate crustal deformation along the Eurasia-Nubia plate boundary in Calabria and Sicily revealed by the GPS velocity field obtained by the combination of
continuous site velocities with previous results from episodic campaigns. We recognize
two distinct crustal domains characterized by different motions and styles of deformation.
Convergence in Sicily is taken up by crustal shortening along the former Tyrrhenian back
arc passive margin, in agreement with seismological data and geological evidence of
recent cessation of deformation along the Plio-Pleistocene subduction front. The analysis
of the GPS data and the consistency between earthquake slip vectors and convergence
direction suggest that Eu-Nu convergence in Sicily does not require intermediate crustal
blocks. Significant Eurasia ( 3 mm/yr to NNE) and Nubia-fixed ( 5 mm/yr to ESE)
residual velocities in Calabria suggest instead the presence of an intermediate crustal block
which can be interpreted as a forearc sliver or as an independent Ionian block. According
to the first hypothesis, subduction is still active in the Ionian wedge, although we find
no evidence for active back arc spreading in the Tyrrhenian Sea. The N115 E oriented
Sicily-Calabria GPS relative motion is consistent with the extension observed during the
1908 Mw 7.1 Messina earthquake. We suggest that up to 3 mm/yr ( 80%) of this
estimated relative motion between Sicily and the Calabrian Arc may be taken up in the
Messina Straits.
Description:
Published
Description:
1-16
Description:
reserved
Keywords:
GPS
;
Calabria, Sicily, Active tectonics
;
04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformations
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Format:
1237090 bytes
Format:
application/pdf
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