Statistical analysis of the nowcasting approach for calculating assessments of the current state along the Iran-Iraq border

In this study, we examined concepts and applications deriving from the use of natural time to understand earthquake dynamics. In particular, the nowcasting concept is used to assess the current state of the fault system and its current level of progress through the earthquake cycle for Kermanshah city (as a centre of the Kermanshah province), in a radius circle of 500 km, as well as a seismic-prone region such as Sarpol-e Zahab and the surrounding area in radius circles of 100, 150, and 200 km. Of note, the nowcasting approach identifies a large seismically active geographic zone within which a local region of interest is embedded. Because statistical measurement of observed seismicity is critical for understanding earthquake dynamics and future risk, we computed the earthquake potential score (EPS) as the cumulative number of small earthquakes since the last large event in the studied region. The EPS values for occurrences with M≥6.0 within radius circles of 100, 150, and 200 km surrounding Sarpol-e Zahab city are 87, 93, and 96%, respectively.