New duration-based local (ML) and moment (Mw) magnitude scales are obtained the Campi Flegrei area through analysis of a dataset of local volcano-tectonic earthquakes. First, the S-wave quality factor for the investigated area was experimentally calculated, and then the distance-correction curve, logAO(r), to be used in the Richter formula ML = log Amax - log AO(r), was numerically estimated by measuring the attenuation properties and, hence, propagating a synthetic S-wave packet in the earth medium. The local magnitude scale was normalized to fit the Richter formula that was valid for Southern California at a distance of 10 km. ML was estimated by synthesizing Wood-Anderson seismograms and measuring the maximum amplitude. For the same dataset, the moment magnitude was obtained from S-wave distance-corrected and site-corrected displacement spectra. Comparisons between local and moment magnitudes determined, along with the old duration magnitude (MD) routinely used at the Istituto Nazionale di Geofisica e Vulcanologia-Osservatorio Vesuviano, are presented and discussed. Moreover, the relationships between ML and Mw calculated for two reference sites are also derived.
Recalibration of the magnitude scales at Campi Flegrei Italy, on the basis of measured path and site and transfer functions / Petrosino S.; de Siena L.; del Pezzo E.. - In: BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA. - ISSN 0037-1106. - STAMPA. - 98:4(2008), pp. 1964-1974. [10.1785/0120070131]
Recalibration of the magnitude scales at Campi Flegrei Italy, on the basis of measured path and site and transfer functions
de Siena L.;
2008
Abstract
New duration-based local (ML) and moment (Mw) magnitude scales are obtained the Campi Flegrei area through analysis of a dataset of local volcano-tectonic earthquakes. First, the S-wave quality factor for the investigated area was experimentally calculated, and then the distance-correction curve, logAO(r), to be used in the Richter formula ML = log Amax - log AO(r), was numerically estimated by measuring the attenuation properties and, hence, propagating a synthetic S-wave packet in the earth medium. The local magnitude scale was normalized to fit the Richter formula that was valid for Southern California at a distance of 10 km. ML was estimated by synthesizing Wood-Anderson seismograms and measuring the maximum amplitude. For the same dataset, the moment magnitude was obtained from S-wave distance-corrected and site-corrected displacement spectra. Comparisons between local and moment magnitudes determined, along with the old duration magnitude (MD) routinely used at the Istituto Nazionale di Geofisica e Vulcanologia-Osservatorio Vesuviano, are presented and discussed. Moreover, the relationships between ML and Mw calculated for two reference sites are also derived.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
