Seismic Cycle and Implications : Case Examples in Taranto Gulf (Southern Apennine Deformation Front)
Deffontaines, Benoit1; Fortunato, Gerardo2; Magalhaes, Samuel3
1Université Paris Est Marne-La-Vallée, FRANCE; 2alphageomega, ITALY; 3alphageomega, FRANCE
Detailed tectonic analyses and geological mapping in muddy fold-belt front is a hard task. Using SAR interferometry (Dinsar and PSI), fieldwork and GIS software associated to new soil datations (and their difficulties) of the different marine terrace levels of the Taranto Gulf (Southern Italy), we re-interprete from an active tectonic point of view the location and cahracterization of the deformation front of the southern Appennines. By combining our data with the known eustatic curve of the mediteranean sea along the southern italian shore, we were able to better understand the landscape evolution of that deformation front and we are now able to differenciate the signal of both active tectonic and eustatic processes and their related geomorphic features on the Taranto Gulf marine terrasses. Therefore the observed seismic cycle of the Southern Apennine deformation front is revealed and appear to be coherent with both a regular intersismic linear creep period (time =251 ka/uplift=71m) and a rapid cosismic uplift (time :10Ka/uplift = 42m). Comparing these data and knowing the geometry of the frontal thrust westarly 3° dipping (agip offshore seismic lines), we calculate the shortening of each return earthquake period which is more than 2,1km for 261ka. This give us new major inputs to better understand the deformation front of Southern Italy.