Comparison of Methods for Path Averaged Attenuated Travel Time Estimation using The Grid Search, Metropolis Algorithm, and Combined Method

Abstract Attenuated travel time ( t *) is one of the key parameters to estimate the seismic attenuation structure. The t * parameter quantifies the amplitude decay of seismic waves and is used as an input for the seismic attenuation tomography method. The Attenuation parameters could be estimated using a spectral fitting procedure from the amplitude spectra equation to obtain the corner frequency (f c ), long-period spectral level (Ω 0 ), and t * values for each pair of stations and events. We compared the grid search, metropolis, and combined algorithm for estimating the attenuation parameters with 15 predefined parameters synthetic data. The result showed that the combined method approach could estimate parameters better than the conventional hyperparameter inversion method (i.e., grid search, random search).