ShakeMap implementation in Italy
Italy is a seismically active country and has been the site of several large and extremely damaging earthquakes since historical times. Tragic examples of these earthquakes in the past century include the M 6.8 1905 Calabria, the M 7.0 1908 Messina-Reggio Calabria, the M 7.0 1915 Marsica, the M 6.7 1930 Irpinia, the M 6.5 1968 Belice, the M 6.5 1976 Friuli, and the M 6.9 1980 Irpinia (Boschi et al. 2000). All these earthquakes caused extensive damage and hundreds to tens of thousands of casualties.

In recent years, the Dipartimento per la Protezione Civile (Italian Civil Protection Department [DPC], which answers directly to the prime minister) has supported several projects in the field of seismology aimed toward a better understanding of the occurrence of earthquakes on Italian territory and their associated ground shaking. In this context, project DPC-S4 2004–2006 was directed specifically at the quick assessment of ground-motion shaking in Italy (see http://www.ingv.it/progettiSV/Progetti/Sismologici/sismologici\_con\_frame.htm, in Italian). The DPC in Italy, and civil defense agencies in general, are indeed in great need of rapid and accurate information on where earthquake damage is located, so they can properly direct rescue teams and organize an emergency response. For these reasons, the Istituto Nazionale di Geofisica e Vulcanologia (INGV) has implemented the software package ShakeMap, developed by the U.S. Geological Survey (USGS) Earthquake Hazards Program (Wald et al. 2006) and specifically designed to generate maps of the peak ground-motion (PGM) parameters and the instrumentally derived intensities.

ShakeMap is capable of generating maps of ground shaking of various PGM including peak ground acceleration (PGA), ground velocity (PGV), and spectral acceleration response (PSA) at 0.3, 1.0 and 3.0 s, and instrumentally derived intensities. At its core, ShakeMap is a seismologically based interpolation algorithm that exploits the available data of the observed ground motions and the …