Time Domain Moment Tensor (TDMT)

The Time Domain Moment Tensors (TDMT) are routinely computed for events with ML >= 3.5 occurring in Italy and in the neighbouring countries. The solutions are automatically obtained through the technique developed at U.C. Berkeley (see http://seismo.berkeley.edu/~dreger/mtindex.html) within 6-9 minutes after the location of an earthquake. The algorithm inverts local to regional three-component broadband velocity waveforms to estimate a point-source solution. Analysts review the automatic solutions and post the results on this web-site. Synthetic seismograms used in the moment tensors computation are calculated by using 1D regionally calibrated, laterally homogeneous layered velocity structures. The Beachball representation is plotted with Lambert projection by using the MoPaD software tool (Krieger L. and Heimann S., Seismol. Res. Lett., 83(3):589-595, 2012). The solution quality is based on the variance reduction, that measures the goodness of fit between data and synthetic , on the percentage of double couple and the number of inverted stations.