Crustal deformation in the northern Apennines, Italy, results from the RETREAT GPS network
Abstract
To determine the present day velocity field across the Northern Apennines a GPS geodetic network was installed and measured annually from 2003 to 2007 as part of the RETREAT collaborative project. Each year additional sites were added to the network to improve coverage and in 2004 we started semi continuous observation of a handful of sites, logging data continuously over the summer months. Of these, two sites have now been logging data continuously since 2004 (COLD, RSMN) and one has been logging data since 2005 (SPEL). We analyze the data along with both regional and global CGPS stations from the EUREF, IGS, RING, ASI and other local networks using GAMIT/GLOBk version 10.3. The observed signal is small (only a few mm/yr relative to stable Eurasia) but the velocity field clearly reveals a complex pattern of deformation, related to syn-convergent extension processes. Along the thrust front we observe deformation perpendicular to the front with a few mm/yr of convergence across the Bologna front. We observe a small but significant extension (1-2 mm/yr) across the Apuane region on the Tyrrhenian side of the Apennines range. We see extension across the Alto Tiberina low angle normal fault of 2-3 mm/yr but additional extension seems to be taken up on older faults to the NW of the Alto Tiberina fault. In addition, a larger wavelength signal of few mm/yr NE motion is observed parallel to the coast on the Tyrrhenian side of the Apennines and seems to overprint other signals in the region.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFM.T13D1987H
- Keywords:
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- 1209 Tectonic deformation (6924);
- 8102 Continental contractional orogenic belts and inversion tectonics;
- 8104 Continental margins: convergent;
- 8105 Continental margins: divergent (1212;
- 8124)