Source Depths Utilizing Broad Band Data
Abstract
The report covers the effort of a two year research project to improve our ability to discriminate between nuclear explosions and earthquakes based on the depth of an event determined from local and regional phases. The approach taken has been to provide phase identification and picking abilities for depth phases pp and sp through adaptive filtering to reduce effects of mode conversion and scattering. Three-component polarization methods are applied to broad-band digital data from a set of earthquakes located in the northeastern United States and from the short period records of the Ocean Sub-bottom Seismometer (OSS) for events in the Kuril/Kamchatka area. Data from the northeast U.S. are compared with suites of synthetic seismograms for different depths and focal mechanisms obtained using two velocity/attenuation models appropriate for northeastern United States and Canada. This comparison provides a basis for identification of the depth phases and discrimination of other reflected/refracted arrivals in the P wavetrain. Polarization state filtering (following procedures proposed by Samson) is used to emphasize those frequencies exhibiting the desired particle motion within a time that slides through the P wavetrain.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 19, 1987
- Accession Number
- ADA182030
Entities
People
- George H. Sutton
- Jerry A. Carter
- Noel Barstow