Discrimination, Detection, Depth, Location, and Wave Propagation Studies Using Intermediate Period Surface Waves in the Middles East, Central Asia, and the Far East

摘要

The objective of this research was to construct surface wave group velocity maps at intermediate periods for the Near East, Central Asia and the Far East and to estimate the possibility of using these maps to extract weak surface wave signals and measure their amplitude spectra. To reach these goals we acquired broadband digital records of more than 1600 events that occurred in and around Eurasia during the period 1976-1998 and recorded by about 170 stations of global and regional networks, and PASSCAL deployments. All data were processed by seismic analysts using the frequency-time analysis package developed at the Univ. of Colorado. Altogether more than 23,000 dispersion curves of Rayleigh waves and 18,500 dispersion curves of Love waves were obtained. We developed a new method for tomographic inversion of these measurements. We studied effects of source group time delays and off-path propagation on tomographic images.