HR: 08:15h
AN: T51E-02    [Abstracts]
TI: Crustal motion along the Eurasia-Nubia plate boundary in the Calabrian Arc and Sicily and active extension in the Messina Straits from GPS measurements
AU: * D'Agostino, N
EM: dagostino@ingv.it
AF: Istituto Nazionale Geofisica Vulcanologia, Via Vigna Murata 605, Rome, 00143 Italy
AU: Selvaggi, G
AF: Istituto Nazionale Geofisica Vulcanologia, Via Vigna Murata 605, Rome, 00143 Italy
AB: 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 sites 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. 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 and Nubia-fixed residual velocities in Calabria suggest instead the presence of an intermediate crustal block which can be interpreted as a forearc sliver or as an indipendent 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 N115řE 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.
DE: 8107 Continental neotectonics
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting