New reversible relationships between ground motion parameters and macroseismic intensity for Italy and their application in ShakeMap

SUMMARY We derived new, reversible relationships between macroseismic intensity (I), expressed in either the European Macroseismic (EMS-98) or Mercalli–Cancani–Sieberg (MCS) scales and peak ground acceleration (PGA), velocity (PGV) spectral (SA) at 0.3, 1.0 3.0 s [SA(0.3), SA(1.0) SA(3.0)] for Italy. adopted orthogonal distance regression technique to fit a quadratic function. This research aims improve motion estimates earthquake hazard applications, calculation of shakemaps To this end, recently published INGe data set was used (https://doi.org/10.13127/inge.2). The new relations are: $$\begin{equation*} I = 3.01 \pm 0.12 + 0.86 0.04 \log ^2 \mathrm{ PGA},~\sigma 0.30,~~\sigma _{\mathrm{ PGA}} 0.25,~~\sigma _{I} 0.16 \end{equation*}$$$$\begin{equation*} 4.31 0.15 1.99 0.18 PGV} 0.58 PGV},~\sigma 0.34,~~\sigma PGV}} \\ 0.31,~~\sigma 2.77 0.68 0.03 SA}(0.3),~\sigma SA}(0.3)} 0.28,~~\sigma 0.14 3.00 0.28 0.91 0.55 SA}(1.0) 0.51 0.20 SA}(1.0),~\sigma 0.40,~~\sigma SA}(1.0)} 0.38,~~\sigma 4.04 1.63 0.19 SA}(3.0) 0.66 SA}(3.0),~\sigma SA}(3.0)} 0.35,~~\sigma \end{equation*}$$where PGA SAs are cm s−2 PGV is s−1. Tests performed assess robustness accuracy results demonstrate that adoption problem suitable choice within range values available set. Comparison with similar regressions Italy evidences proposed provide statistically significant improved fits data. also tested by inserting them ShakeMap system Italian configuration evidencing improvement when compared those implemented.