Abstract
This study provides new seismological information to characterize the seismically active area of the Gioia Tauro basin (southern Calabria, Italy). Seismic activity recorded by a temporary network from 1985 to 1994 was analyzed for focal mechanisms, stress tensor inversion, P-wave seismic attenuation and earthquake source parameters estimation. Fault plane solutions of selected events showed a variety of different mechanisms, even if a prevalence of normal dip-slip solutions with prevalent rupture orientations occurring along ca. NE-SW directions was observed. Stress tensor inversion analysis disclosed a region governed mainly by a NW-SE extensional stress regime with a nearly vertical ?1. These results are consistent with the structure movements affecting the studied area and with geodetic data. Furthermore, evaluation of P-waves seismic attenuation and earthquake source parameters of a subset of events highlighted a strong heterogeneity of the crust and the presence of fault segments and/or weakened zones where great stress accumulation or long-rupture propagation are hindered.
Highlights
The Calabrian arc is the most arcuate southern part of the Mediterranean orogenic belt
For point-like impulsive sources it is expressed by the linear relation: τ = τ 0 + CT / Qp where t 0 is the original pulse width at the source, T is the travel time, QP is the quality factor of P-waves and C is a constant which is equal to 0.5 for a constant Q attenuation operator (Kjartansson, 1979)
Data from a 9-year time span recorded by a temporary network deployed in southern Calabria from 1985 to 1994 were analyzed for earthquake focal mechanisms, stress tensor inversion, P-wave seismic attenuation and earthquake source parameters estimation
Summary
The Calabrian arc (fig. 1) is the most arcuate southern part of the Mediterranean orogenic belt. The arc connects the E-W and the NW-SE trending branches of the belt, which are represented by the Maghrebian and the southern Apennines chains, respectively. The most impressive tectonic feature of the arc is a prominent normal fault belt that extends, more or less continuously, for a total length of about 180 km along the inner side of the arc (Tortorici et al, 1995). With a 1 to 3 m high frontal scarp that, in some places, has a free face (Wallace, 1977). It is composed of a dozen en echelon strands, 1-3 km long which strike N40°E, with the exception of two N25°E relay ramps. Almost all the strands show a right step with respect to the northern ones (Galli and Bosi, 2002)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
