Accession Number : ADA193562


Title :   Body and Surface Wave Modeling of Observed Seismic Events Part 3.


Descriptive Note : Final rept. 14 Jul 86-13 Jan 87,


Corporate Author : CALIFORNIA INST OF TECH PASADENA SEISMOLOGICAL LAB


Personal Author(s) : Clayton, Robert W ; Harkrider, David G ; Helmberger, Donald V


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA193562


Report Date : 13 May 1987


Pagination or Media Count : 142


Abstract : The research can be divided into two main topics; coupling line source calculations in 2-D lateral variations of near source structure to analytic teleseismic body wave codes, and the effects of ocean continent transition zones on L sub g waves. A new method is presented for interfacing numerical and integral techniques which allows greater flexibility in seismic modeling. Specifically, numerical calculations in laterally varying structure are interfaced with analytic methods that enable propagation to great distances. Such modeling is important in studying situations containing localized complex regions not easily handled by analytic means. The effects of the length of the intermediate path between the continent ocean and ocean continent transition regions is investigated. First the results of two FE calculations with different intermediate path lengths are presented and compared. These examples are contrasted with the path length used in the previous report. Then the RT integration method is discussed and explained. First analytic expressions for the stress components of double couple and line sources are derived, then the expressions for displacement and stress line source Green's functions are determined. These expressions are used to illustrate the validity and determine the accuracy of the RT coupling method.


Descriptors :   *SEISMOLOGY , *SEISMIC WAVES , *UNDERGROUND EXPLOSIONS , ACCURACY , ANALYTIC FUNCTIONS , COMPUTATIONS , COUPLING(INTERACTION) , INTEGRATION , LENGTH , MODELS , NUMERICAL METHODS AND PROCEDURES , OCEANS , PATHS , PROPAGATION , REGIONS , SOURCES , STRESSES , SURFACE WAVES , TRANSITIONS , MATHEMATICAL MODELS , GREENS FUNCTIONS , FINITE DIFFERENCE THEORY


Subject Categories : Seismic Detection and Detectors
      Seismology
      Explosions


Distribution Statement : APPROVED FOR PUBLIC RELEASE