DATA USABLE BANDWIDTH FOR EARTHQUAKESRECORDED ON SSA۲ ACCELEROGRAMS OF IRANSTRONG MOTION NETWORK (ISMN)

Seismic data processing in engineering seismology often involves bandpass filtering, a critical stepin analyzing strong motion data. This study focuses on selecting the usable data bandwidth usingaccelerograms from the Iran Strong Motion Network (ISMN) recorded by SSA۲ devices. Criteria forestablishing the lowest usable frequency included signal-to-noise ratios, Fourier Amplitude Spectra(FAS) shape analysis, and visual inspection of filtered time series. An iterative process was employedto adjust filter corner frequencies, resulting in different frequency band limits for each recordingcomponent. The upper-frequency limit is heavily influenced by the limitations of recording equipment.For ۹۰% of the current dataset, the usable bandwidth ranges from ۰.۳۵ Hz to ۸ Hz. The methodologyoutlined in this study provides insights into selecting appropriate frequency ranges for subsequentseismological analyses.

Keywords:

Earthquakes , Data Processing , Iran Strong Motion N etwork , SSA۲ Accelerographs