Map of Expected Earthquakes (a Modified Medium-Term Earthquake Forecast Method): Retrospective Statistical Characteristics of Prognostic Indicators

This paper continues a series of publications on the modification of the Map of Expected Earthquakes (MEE), a method of medium-term earthquake forecasting. It is devoted to the calculation and analysis of retrospective statistical characteristics of dynamic and quasi-stationary prognostic indicators in the Kamchatka region used at this stage in the modernized MEE method. In our calculations we used the regional catalog of earthquakes in Kamchatka over the period from 1962 to 2020. The object of the forecast were earthquakes with Kforecast ≥ 13.5. The slope of the recurrence frequency graph γ with an efficiency value of Jt = 10.7 and JS = 11.3 appeared as one of the most effective precursors for the Kamchatka region, both in time and area. The next most effective (in terms of time) precursor was the number of earthquakes Neq in quiescence form with Jt = 5.8. In terms of area, the most effective precursor is the released seismic energy E2/3, also in quiescence form with JS = 14.7. The value of unconditional probability P(D1) of the occurrence of a strong earthquake was calculated based on a set of dynamic indicators, which turned out to be equal to 0.09. A map of the stationary conditional probability of a strong earthquake has been constructed that takes into account the stationary prognostic indicator “presence of faults in a cell” with values of 0.01 (in the cells where there are no faults) and 0.13 (in the cells where there are). As part of the next stage of work, it is planned to continue expanding the functionality of the algorithm for the medium-term forecast of the MEE. The ultimate goal of modernization is the development of a digital problem-oriented system for medium-term earthquake forecasting using a set of prognostic indicators.