Seismic Studies of Regional Path Properties of Eurasia. Part I

摘要

The goal of this study has been to improve the basis for predicting regional path properties encountered by surface waves propagating in Eurasia. At regional distances the observed seismograms are severely influenced by seismic structure along the path between the source and the receiver. Accurate earth models therefore play a critical role in the ability both to detect small events and to discriminate between earthquakes and explosions. Once the regional earth properties and the mode of seismic wave propagation are well understood, seismic source characterization will be much more reliable. The successful completion of modeling regional seismic surface waves requires several steps: (1) construct starting models for each geologic province that are based on a review and synthesis of the geologic and seismic literature; (2) review and collect seismic data for paths crossing each geologic province; (3) reduce the seismic data to group and phase velocity dispersion curves; (4) invert the dispersion data to improve the regional models. This report summarizes work completed during the first year of a two-year effort. Although several path averaged models that match the observations have been derived during this contract year, the primary emphasis has been in the first three tasks listed above.