Relatore: dr. Francesco Grigoli, Università di Potsdam, Germania (seminario ore 12.00, aula 1G09 del Dipartimento Scienze Fisiche, Complesso Universitario di Monte S.Angelo - Via Cinthia, Napoli).
Abstract
Automated seismic event location is a very important task in microseismic monitoring operations.
In such applications we generally deal with a large number of seismic events and locating them manually is time consuming or, in some case, impossible. Standard automated location routines are based on the automatic picking and identification of the main seismic phases (generally P and S first onsets). In the last 20 years a large number of picking algorithms have been developed in order to locate seismic events automatically. While P onsets can now be accurately picked using automated routines, the automatic picking of later seismic phases (including S onset) is still problematic , thus limiting the location performance. Furthermore, microseismic data are often charaterized by a low signal-to-noise ratio and phase identification might be very difficult. In this work we present a picking free location method based on the use of the Short-Term-Average/Long-Term-Average (STA/LTA) traces at different stations as observed data. We will show application to microseismic event location in mines and geothermal fields. Furthermore we will show results concerning the automated locatiosn of a small magnitude earthquake occurred in southern Italy.