“…Many methods have been proposed for Q estimation from seismic data, such as the spectral ratio method (McDonal et al, 1958;Hauge, 1981;Blias, 2012;Reine et al, 2012;Nakata et al, 2020), the matching method (White, 1980), the amplitude decay method (Tonn, 1991), the analytical signal method (Engelhard, 1996), the frequency shift method (Quan and Harris, 1997;Zhang and Ulrych, 2002;Gao and Yang, 2007;Hu et al, 2013;Matsushima et al, 2016;Li et al, 2020;Yang et al, 2020), the Q-tomography method (Brzostowski and McMechan, 1992;Dutta and Schuster, 2016) and the Q-analysis method (Wang, 2004;2014). Among the above-mentioned methods, the spectral ratio method and the frequency shift method are widely used in practice, which estimate Q values by comparing the frequency content of two individual waveforms at different depths or time levels.…”