Abstract
Abstract. Improving the knowledge of seismogenic faults requires the integration of geological, seismological, and geophysical information. Among several analyses, the definition of earthquake focal mechanisms plays an essential role in providing information about the geometry of individual faults and the stress regime acting in a region. Fault plane solutions can be retrieved by several techniques operating in specific magnitude ranges, both in the time and frequency domain and using different data. For earthquakes of low magnitude, the limited number of available data and their uncertainties can compromise the stability of fault plane solutions. In this work, we propose a useful methodology to evaluate how well a seismic network, used to monitor natural and/or induced micro-seismicity, estimates focal mechanisms as a function of magnitude, location, and kinematics of seismic source and consequently their reliability in defining seismotectonic models. To study the consistency of focal mechanism solutions, we use a Bayesian approach that jointly inverts the P/S long-period spectral-level ratios and the P polarities to infer the fault plane solutions. We applied this methodology, by computing synthetic data, to the local seismic network operating in the Campania–Lucania Apennines (southern Italy) aimed to monitor the complex normal fault system activated during the Ms 6.9, 1980 earthquake. We demonstrate that the method we propose is effective and can be adapted for other case studies with a double purpose. It can be a valid tool to design or to test the performance of local seismic networks, and more generally it can be used to assign an absolute uncertainty to focal mechanism solutions fundamental for seismotectonic studies.
Highlights
Fault plane solutions represent primary information to describe earthquakes
The definition of earthquake focal mechanisms plays an essential role in providing information about the geometry of individual faults and the stress regime acting in a region
By computing synthetic data, to the local seismic network operating in the Campania– Lucania Apennines aimed to monitor the complex normal fault system activated during the Ms 6.9, 1980 earthquake
Summary
Fault plane solutions represent primary information to describe earthquakes. The assessment of earthquake location, magnitude, and focal mechanism are the fundamental operations to characterize the earthquake source using a point source approximation. The focal mechanism describes the basic geometry and kinematics of a point source in terms of strike, dip, and rake of the fault plane along which the earthquake occurred. The focal mechanism is the most important marker of the geometry of the seismogenic faults and their style of faulting. Seismicity and focal mechanisms of events are often used to constrain seismotectonic models, individual seismogenic sources, the regional strain, and stress fields, for small magnitudes. An evaluation of their effective reliability becomes a fundamental issue in seismotectonic studies
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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.
