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Shapira, Avi
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- PublicationOpen AccessAn Operational Earthquake Forecasting Experiment for Israel: Preliminary Results(2021-09)
; ; ; ; ; ; ; ; ; ; ; ; ; Operational Earthquake Forecasting (OEF) aims to deliver timely and reliable forecasts that may help to mitigate seismic risk during earthquake sequences. In this paper, we build the first OEF system for the State of Israel, and we evaluate its reliability. This first version of the OEF system is composed of one forecasting model, which is based on a stochastic clustering Epidemic Type Earthquake Sequence (ETES) model. For every day of the forecasting time period, January 1, 2016 - November 15, 2020, the OEF-Israel system produces a weekly forecast for target earthquakes with local magnitudes greater than 4.0 and 5.5 in the entire State of Israel. Specifically, it provides space-time-dependent seismic maps of the weekly probabilities, obtained by using a fixed set of the model’s parameters, which are estimated through the maximumlikelihood technique based on a learning period of about 32 years (1983–2015). According to the guidance proposed by the Collaboratory for the Study of Earthquake Predictability (CSEP), we also perform the N- and S-statistical tests to verify the reliability of the forecasts. Results show that the OEF system forecasts a number of events comparable to the observed one, and also captures quite well the spatial distribution of the real catalog with the exception of two target events that occurred in low seismicity regions.149 10 - PublicationOpen AccessElectrotelluric noise minimization for seismoelectric effect detection(1997-03)
; ; ;Shirman, B.; Seismology Division, Institute for Petroleum Research and Geophysics, Holon, Israel ;Shapira, A.; Research Department, Survey of Israel, Tel-Aviv, Israel; Three electrotelluric stations were installed in Israel in order to examine electric field changes associated with earthquake occurrence at the Bar-Giora observatory, at the Ein Gedi field school and on Mt. Tur'an. During the observation period 1994-1995, no earthquake was shown to cause any changes in the electric field at the measurement sites. This study focused on signal processing of electric field continuous measurements. The main purpose was to identify, and consequently filter out, signals caused by local and extra-terrestrial sources. New procedures for data processing were developed mainly using data from the Bar-Giora station, which has been instrumental in the experiments.113 306