Setting up an earthquake forecast experiment in Italy

We describe here the setting up of the first earthquake forecasting experiment for Italy within the Collaboratory for the Study of Earthquake Predictability (CSEP). The CSEP conducts rigorous and actual prospective forecast experiments for different tectonic environments in several forecast-testing centers around the globe. These forecasts are issued for future periods, and are tested only against future observations, to avoid any possible bias. As such, the experiments need to be completely defined. This includes exact definitions of the testing area, of the learning data for the forecast models, and of the observation data against which the forecasts will be tested to evaluate their performance. We present the rules that were taken from the Regional Earthquake Likelihood Models experiments and extended and modified for the Italian experiment. We also present the characterizations of the learning and observational catalogs that describe the completeness of these catalogs, and reveal inhomogeneities in the magnitudes between these catalogs. A particular focus lies on the stability of the earthquake recordings of the observational network. These catalog investigations provide guidance for CSEP modelers for the development of earthquakes forecasts for submission to the forecast experiments in Italy.