A double-branching model applied to long-term forecasting of italian seismicity (mL ≥ 5.0) within the CSEP project

The purpose of this study was to apply a double-branching model to forecasting of moderate-to-large Italian seismicity within the Collaboratory Study for Earthquake Predictability project. This project is designed for statistical evaluations and comparisons of various forecasting models, on both the global and regional scales. This proposed doublebranching model is time-dependent, as it assumes that each earthquake can generate, or is correlated with, other earthquakes through physical mechanisms that act on different spatio-temporal scales. Specifically, it consists of an application of two branching processes, in which any earthquake can trigger a family of later events on different space-time scales. In our recent study [Lombardi and Marzocchi 2009], we applied this model to a declustered historical database that included the strong Italian seismicity from over the last few centuries. This catalog only allowed us to describe the long-term time evolution of moderate-to-strong seismicity. Here, we have applied this double-branching model to a new database that has allowed us to describe both short-term clustering and long-term features at the same time. As the model can produce forecasting calculations of future seismicity, we provide some probability maps of occurrence of predicted events over different temporal windows. © 2010 by the Istituto Nazionale di Geofisica e Vulcanologia.