Combining seismic reflection with multifold wide‐aperture profiling: An effective strategy for high‐resolution shallow imaging of active faults

Abstract

[1] Shallow imaging of fault zones is a challenging task. We investigate if this issue can be successfully addressed by combining reflection seismics with non-standard multifold wide-aperture profiling, a strategy pertaining to crustal scale exploration so far. Near-offset reflection and multifold wide-aperture data are simultaneously recorded along two profiles in a small basin crossed by an active fault in Southern Italy. Imaging consists of multiscale seismic tomography complemented by CDP processing of nearoffset reflections and of data spanning a large offset range. By combining smooth Vp and reflectivity images we pinpoint the fault location and yield a valuable picture of the basin. Performance of each exploration technique strongly varies in the two surveys depending on the local geology. Thus, the combined exploration strategy not only yields complementary images for enhanced interpretation, but also allows extending the range of applicability of shallow seismics for fault detection, reducing the risk of unsuccessful investigations. Citation: Improta, L., and P. P. Bruno (2007), Combining seismic reflection with multifold wideaperture profiling: An effective strategy for high-resolution shallow imaging of active faults, Geophys. Res. Lett., 34, L20310,

Active faults and induced seismicity in the Val d’Agri area (Southern Apennines, Italy)

“…11), the main southern strand of the MMFS (Maschio et al 2005). Our result supports the contention that this fault is active, extending and corroborating field data and shallow seismic prospecting, indicating coseismic faulting in LatePleistocene Holocene deposits (Maschio et al 2005;D'Addezio et al 2006;Improta & Bruno 2007).…”

Stress aligned cracks in the upper crust of the Val d'Agri region as revealed by shear wave splitting

“…Conversely, Maschio et al (2005) present an alternative model, in which the basin evolution of the basin has been controlled because Upper Pleistocene by a NE-dipping normal-fault system recognized to the west of the basin, along the Maddalena ridge (here on after, Monti Maddalena Fault System; MMFS in Figs 2 and 3a). This structure, whose recent faulting activity is also inferred by high-resolution seismics prospecting (Improta & Bruno 2007) and paleoseismic trenches (D'Addezio et al 2006), is quoted as the main fault of the area (Maschio et al 2005). Passive seismic data corroborate this hypothesis, highlighting the presence of micro-seismicity aligned on a NW-trending, NE-dipping fault between 1 and 6 km depth that can be related to southern splays of the MMFS (Valoroso et al 2009).…”

Processing and preliminary interpretation of noisy high-resolution seismic reflection/refraction data across the active Ostler Fault zone, South Island, New Zealand

“…Seismic imaging of active fault zones and shallow glacial deposits are separately demanding tasks (Büker et al, 1998;Pratt et al, 1998;Long et al, 2003;Spitzer et al, 2003;Improta and Bruno, 2007). The combination of these two settings in the Mackenzie Basin results in an extremely complex structural environment, requiring the careful application of innovative processing strategies to ensure the extraction of maximum information from the seismic data while avoiding the creation of artefacts (Steeples et al, 1997).…”