Attenuation of Regional Phases in Fennoscandia and Estimates of Arrival Time and Azimuth Uncertainty Using Data Recorded by Regional Arrays.

摘要

The primary objective of this project is to simulate the detection and location capability of seismic networks that include regional stations and arrays in and around the Soviet Union. This report summarizes several studies of important issues for normalizing these simulations. Initial application is to data recorded by the NORESS and ARCESS arrays in Norway because of the size and quality of the data set and the fact the independence networks provide accurate locations of regional events. Azimuth and arrival time uncertainty are estimated for data recorded by these arrays to normalize simulations and location capability. The normalized simulation method is used to predict the detection and location capability of NORESS and ARCESS. These simulations are compared to the capability actually achieved by these arrays to validate the normalization. This method is shown to give accurate results for NORESS and ARCESS, so it can determine the sensitivity to network parameters (e.g., number stations, number of arrays versus single stations, noise levels, etc). The next step is to extrapolate the NORESS/ARCESS results to predict the capability of hypothetical networks in the Soviet Union. However, it is important to include lateral variations in propagation characteristics to simulate capability for such a large area. Therefore, a tectonic map of Eurasia is used to develop a 5 X 5 deg propagation grid. Source coupling is also important for accurate simulations, so a map of the surface geology of Eurasia is used as a guide to identify potential sites for cavity decoupling (e.g., regions of bedded or domed salt).