Highlights

A Local Magnitude Scale for Southern Italy

Bullettin of  of Seismological Society of America,Vol. 99, No.4, 2461–2470, 2009 doi: 10.1785/0120080364

Bobbio A., Vassallo M., Festa G.

Abstract

A local magnitude scale has been defined for southern Italy, in the area monitored by the recently installed Irpinia Seismic Network. Waveforms recorded from more than 100 events of small magnitude are processed to extract synthetic Wood–Anderson traces. Assuming a general description of peak-displacement scaling with the distance, by means of linear and logarithmic contributions, a global exploration of the parameter space is performed by a grid-search method with the aim of investigating the correlation between the two decay contributions and seeking for a physical solution of the problem. Assuming an L2 norm, we found M =log A +1.79 log R - 0.58; yielding an error on the single estimation smaller than 0.2, at least when the hypocenter location is accurate. Station corrections are  investigated through the station residuals, referring to the average value of the magnitude. Using a z test, we found that some stations exhibit a correction term significantly different from 0. The use of the peak acceleration and peak velocity as indicators of the magnitude is also investigated.

 {mosimage} download pdf

*Notice: This is an electronic version of an article published in Bulletin of the Seismological Society of America: complete citation information for the final version of the paper, as published in the print edition of Bulletin of the Seismological Society of America, is available on the  Seismological Society of America (SSA) online delivery service, accessible via the journal's website at ttp://www.seismosoc.org/publications/bssa.html