Accession Number : ADP204479

Title :   Incorporating 'Sinuous Connectivity' into Stochastic Models of Crustal Heterogeneity: Examples from the Lewisian Gneiss Complex, Scotland, the Francsican Formation, California, and the Hafafit Gneiss Complex, Egypt,

Corporate Author : TEXAS UNIV AT AUSTIN INST FOR GEOPHYSICS

Personal Author(s) : Goff, John A. ; Levander, Alan

PDF Url : ADP204479

Report Date : 14 AUG 1995

Pagination or Media Count : 10

Abstract : Stochastic models are valuable and sometimes essential tools for investigating the behavior of complex phenomena. In seismology, stochastic models can be used to describe velocity heterogeneities that are too small or too numerous to be described deterministically. Where analytic approaches are often infeasible, synthetic realizations of such models can be used in conjunction with finite difference algorithms to systematically investigate the response of the seismic wavefield to complex heterogeneity. This paper represents a continuing effort at formulating a complete and robust stochastic model of lithologic heterogeneity within the crust, and the means of generating synthetic realizations; 'complete' implies that the model is flexible enough to describe all types of random heterogeneity within the crust, while 'robust' implies sufficiently constrained parameterization that an inversion problem may be well-posed. We use as a basis for investigation geologic maps of crustal exposures and petrophysically inferred velocities. Earlier efforts at stochastic modeling have focused on characterization of the univariate probability density function, which is typically modal (i.e., binary, ternary, etc.), and the covariance function, which is typically fit with a von Karman function. Here we provide a means of characterizing the property of 'sinuous connectivity' and for generating realizations that possess this property. Sinuous connectivity is the tendency for individual lithologic units to be continuous over long and highly contorted paths; there is no means in the earlier modeling of either characterizing or synthesizing this property.

Descriptors :   *SEISMIC DETECTION, *EARTH CRUST, *SEISMIC WAVES, *ARMS CONTROL, *NUCLEAR EXPLOSION DETECTION, *LITHOLOGY, SYMPOSIA, STOCHASTIC PROCESSES, EGYPT, MONITORING, UNDERGROUND EXPLOSIONS, PROBABILITY DENSITY FUNCTIONS, NUCLEAR EXPLOSION TESTING, FINITE DIFFERENCE THEORY, HETEROGENEITY, CALIFORNIA, SEISMIC DISCRIMINATION, SEISMIC VELOCITY, DIGITAL MAPS, ASPECT RATIO, PRIMARY WAVES(SEISMIC WAVES), VOLCANOES, LITHOSPHERE, SCOTLAND.

Subject Categories : Government and Political Science
      Geology, Geochemistry and Mineralogy
      Seismology
      Seismic Detection and Detectors
      Nuclear Weapons

Distribution Statement : APPROVED FOR PUBLIC RELEASE