Earthquake Potential Assessment of Hualien City, Taiwan Using Natural Time and Earthquake Nowcasting Method

Knowing the present seismicity potential of a region with regard to the large earthquake cycles is of great importancefor preparedness and planning measures. This study investigates the concept of nowcasting, which addresses theuncertainties involved in assessing earthquake risks, focusing on the M ۷.۴ earthquake that occurred on April ۲, ۲۰۲۴,in Hualien City, Taiwan. We utilized the natural time framework, rather than traditional clock time, to examine thestatistical distribution of interevent counts for minor seismic occurrences between major earthquakes. The earthquakepotential score (EPS) was determined by assessing the cumulative count of minor seismic events that occurredsubsequent to the last significant earthquake within the specified region. We assessed EPS values for events ofmagnitude ۴.۹ and above within three distinct radii (۲۰۰, ۲۵۰, and ۳۰۰ km) from the epicenter of the earthquake. TheEPS values for Hualien City at a ۱۰۰ km radius, corresponding to ۶۶ minor events of magnitude ۴.۹ and above, wasranged from ۰.۷۲ to ۰.۸۲. At a ۲۰۰ km radius, these values increased to between ۰.۸۹ and ۰.۹۳, based on ۴۷ minorevents. while at a ۳۰۰ km radius, considering ۲۴ minor events, the EPS was calculated to be ۰.۹۶.

کلیدواژه ها:

NOWCASTING ، NATURAL TIME ، EARTHQUAKE POTENTIAL SCORE ، EARTHQUAKE HAZARD