6:15 PM - 7:30 PM
[SSS30-P04] Consideration of the Method to Estimate the Radiated Seismic Energy from Regional Seismic Waveforms
Keywords:Seismic radiated energy, Moderate earthquake
For the purpose of investigating these questions, we need to estimate and compare the radiated seismic energies correctly from several different phases. As an example, we focus on a moderate earthquake (June 14, 2008 at 12:27, Mw 4.9 from F-net) that occurred just after 2008 Iwate-Miyagi Nairiku earthquake. In this study we estimate the radiated seismic energy from regional P waves, S waves, and S wave coda using an empirical Green's function (EGF) method. The regional waveform data are recorded at stations of Hi-net. Firstly, using cross correlation, we select an EGF event that is highly correlated with the target event. Secondly, we deconvolve the seismograms in frequency domain with a multitaper method (Prieto et al., 2009), and check the waveform in time domain. Thirdly, we fit the obtained spectrum to an omega square model (Brune, 1970, 1971) to estimate the corner frequency. In addition, we try to vary the value of the power for the high-frequency fall-off. Finally, we calculate the radiated seismic energy using these spectra.
The regional waveform data of Hi-net and focal mechanisms of F-net were provided by NIED.