Accession Number : ADA321752

Title :   Research on Seismic Monitoring at Regional Distances.

Descriptive Note : Scientific rept. no. 1,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE EARTH RESOURCES LAB

Personal Author(s) : Dong, Wenjie ; Gibson, Richard L., Jr. ; Imhof, Matthias G. ; Toksoez, M. N.

PDF Url : ADA321752

Report Date : 15 OCT 1996

Pagination or Media Count : 87

Abstract : We report two studies related to numerical modeling of seismic wave generation and propagation. In the first, numerical calculations of seismic wave scattering using the multiple multipole technique are compared to laboratory data that we collected in an ultrasonic experiment. The results demonstrate the validity of the multiple multipole approach for seismic wave propagation modeling. The second study investigates seismic radiation from explosively loaded cavities in isotropic and transversely isotropic media. Theoretical calculations of source radiation patterns show that small, decoupled explosions in cylindrical cavities will generate shear waves with amplitude depending on cavity shape (ratio of length to width). The calculations also show the interesting result that locating such a cavity in transversely isotropic media can, in special cases, actually produce less shear wave energy than in an isotropic medium.

Descriptors :   *MONITORS, *SEISMIC DISCRIMINATION, MATHEMATICAL MODELS, SCATTERING, ISOTROPISM, DECOUPLING, SEISMIC WAVES, NUCLEAR EXPLOSION DETECTION, MULTIPOLARITY, RADIATION PATTERNS.

Subject Categories : Seismic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE