Seismic Wave Propagation Through Random Media

Haruo Sato is Professor Emeritus at Tohoku University, Japan. He is an expert in observation and theoretical physics in seismology and solid Earth geophysics. He was awarded with the 2018 Beno-Gutenberg Medal by the European Geosciences Union (EGU) for outstanding contributions to seismology and the development of new insights into stochastic properties of Earth structure through theoretical and observational studies of scattered seismic waves. He was also made a Japan Science Union fellow in 2018 and was elected to be an honorary member of the Seismological Society of Japan in 2019.

The solid Earth's medium is heterogeneous over a wide range of scales. Seismological observations, including envelope broadening with increasing distance from an earthquake source and the excitation of long-lasting coda waves, provide a means of investigating velocity inhomogeneities in the crust. These phenomena have been studied primarily using radiative transfer theory with random medium modelling. This book presents the mathematical foundations of scalar- and vector-wave scattering in random media, using the Born or Eikonal approximation, which are useful for understanding random inhomogeneity spectra and the scattering characteristics of the solid Earth. A step-by-step Monte Carlo simulation procedure is presented for synthesizing the propagation of energy density for impulsive radiation from a source in random media. Simulation results are then verified by comparison with analytical solutions and finite-difference simulations. Presenting the latest seismological observations and analysis techniques, this is a useful reference for graduate students and researchers in geophysics and physics.

Preface; 1. Introduction; 2. RTT for the isotropic scattering model; 3. Scattering of scalar waves in random media; 4. RTT for scalar wavelet propagation through random media; 5. FD simulation of scalar wavelet propagation through random media; 6. RTT for vector wavelet propagation through random elastic media; 7. Hybrid MC simulation using the spectrum division; 8. Epilogue; References; Index