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Forearc extension and slow rollback of the Calabrian Arc from GPS measurements
Author(s) -
D'Agostino Nicola,
D'Anastasio Elisabetta,
Gervasi Anna,
Guerra Ignazio,
Nedimović Mladem R.,
Seeber Leonardo,
Steckler Michael
Publication year - 2011
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2011gl048270
Subject(s) - geology , subduction , forearc , seismology , reference frame , geodesy , foreland basin , trench , arc (geometry) , wedge (geometry) , global positioning system , tectonics , geometry , frame (networking) , chemistry , organic chemistry , layer (electronics) , telecommunications , mathematics , computer science
Here we describe the horizontal velocities of continuous GPS stations in the Calabrian Arc (CA) and surrounding regions. The appropriate reference frame to evaluate the crustal motion of the CA is considered by assessing the internal deformation and the relative motion of the crustal blocks in the foreland of the Apennines‐Ionian‐Maghrebides subduction system. We propose that the motion of CA relative to the subducting Ionian lower plate is most properly assessed by minimizing the GPS velocities in Apulia. In this reference frame the significant ≈2 mm/yr southeastward motion of the stations on the Ionian flank of the CA shows that the arc is still moving towards the trench in agreement with the observations of active shortening in the Ioanian wedge. This southeastward migration is associated to 1.4 ± 0.3 mm/yr E‐W extension of the forearc in northern Calabria, comparable with the seismic strain averaged in the last 500 years. The limited subaerial exposure decreases the resolution on locking of the subduction interface but the distribution and direction of crustal extension along the CA impose important constraints on geodynamic interpretations of the area.