Finite element modelling of stress field perturbations and interseismic crustal deformation in the Val d'Agri region, southern Apennines, Italy

Inversion of inherited thrusts by wastewater injection induced seismicity at the Val d’Agri oilfield (Italy)

“…According to previous studies14151624, thrust faults affecting the allochtonous stack sole on the mélange basal detachment and are not connected with the high angle reverse faults developed within the API, which in turn rarely propagate upwards (Figs 2A and S3, S4). The upper allochtonous units are characterized by well-organized high frequency reflectors defining a syncline filled by Miocene turbiditic terrigenous sequences, which are un-conformably covered by wedge-top deposits (Fig.…”

Reservoir Structure and Wastewater‐Induced Seismicity at the Val d'Agri Oilfield (Italy) Shown by Three‐Dimensional Vp and Vp/Vs Local Earthquake Tomography

“…In Figure we compare the V p depth slice of 2 km to the structural map of the IAP top obtained by integrating the regional structural model of the Apulian Platform (Nicolai & Gambini, ) with published subsurface local data (Dell'Aversana, ; Shiner et al, ; Mazzoli et al, ; Candela et al, ; Buttinelli et al, ; D'Adda et al, ). The agreement between high‐ V p bodies and structural highs of the reservoir is evident.…”

“…High‐ V p regions detected under both ridges positively correlate with areas where the reservoir top is above 2 km. Under the central southern sector of the basin, the broad low‐ V p region ( V p < 5.3 km/s) agrees partly with the IAP that deepens westward down to 3 km depth in the footwall of a major NE dipping back thrust of the VA flower structure (Figures b, b, and ) (Candela et al, ; D'Adda et al, ). Indeed, a 5 km wide pop‐up structure of the IAP reached by several oil wells does not correspond to any clear high‐ V p zone in the depth slice of 2 km (see label a in Figure ), and local V p values (5.0–5.3 km/s) are remarkably lower than those typical of the Apulian carbonates.…”

“…The VA hosts a 500 m deep basin bounded by two WNW trending and oppositely dipping fault systems: the Eastern Agri transtensional Fault System to the northeast (EAFS, Cello et al, ) and the Monti della Maddalena extensional Fault System to the southwest (MMFS, Maschio et al, ) (Figure a). Both systems consist of arrays of separated fault segments typical of immature extensional systems (Maschio et al, ), and the geometry of the surface basin‐bounding faults at depth is uncertain (Candela et al, ). In particular, recent interpretations of seismic profiles and analogue modeling found a decoupling between surface normal faults affecting the shallow structural levels and deep‐seated faults in the IAP caused by the ductile and thick mélange that acts as an effective mechanical decoupling layer (Candela et al, ; D'Adda et al, ).…”

“…Both systems consist of arrays of separated fault segments typical of immature extensional systems (Maschio et al, ), and the geometry of the surface basin‐bounding faults at depth is uncertain (Candela et al, ). In particular, recent interpretations of seismic profiles and analogue modeling found a decoupling between surface normal faults affecting the shallow structural levels and deep‐seated faults in the IAP caused by the ductile and thick mélange that acts as an effective mechanical decoupling layer (Candela et al, ; D'Adda et al, ). The MMFS is quoted as the main seismogenic structure of the region based on field surveys, paleoseismic trenches, near‐surface geophysical prospecting, and GPS data (Ferranti et al, ; Improta et al, , and references therein).…”