Subduction Interface Earthquake Rise-Time Scaling Relations

The slip duration in a fault plane, also known as the rise time (Tr), is determined in finite -fault rupture models (FFRMs) through the analysis of seismic source inversions using strong ground -motion (SGM) records and teleseismic data. For subduction interface earthquakes (megathrust), models exist that provide estimates for Tr values. The finite -source rupture model database and National Earthquake Information Center databases include FFRMs that allow for the extension of source -scaling relations. Currently, Tr versus seismic moment (M0) scaling relations specifically derived for large megathrust earthquakes in the near -source region are scarce. The relationship between stress drop and M0 is not straightforward; therefore, the logarithmic distribution of stress drop among earthquakes of different magnitudes (Mw) appears to be constant or self -similar. This self -similarity refers to a symmetry of the time -dependent fields, which remain unchanged under certain scale transformations in space and time characterized by similarity exponents and a function of the scaled variable, called the scaling function. In this study, Tr scaling has been conducted using 45 FFRMs derived from large megathrust earthquakes (Mw >= 7:3) obtained from the previously mentioned databases. The scaling relation derived from the FFRMs based on SGM records closely approximates log (Tr) = const + 1=3 log (M0), which agrees with the self -similarity assumption for earthquake ruptures. On the other hand, the scaling relation obtained from the teleseismic dataset exhibits a smaller slope, indicating that the teleseismic data may overestimate source time characteristics compared with SGM data from seismic stations located close to the source.