Accession Number : ADA292188

Title :   Regional Seismic Event Identification and Improved Locations With Small Arrays,

Corporate Author : SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA

Personal Author(s) : Vernon, Frank L. ; Minster, J. B. ; Orcutt, John A.

PDF Url : ADA292188

Report Date : 06 JUL 1994

Pagination or Media Count : 32

Abstract : As part of our work in receiver site characterization we have written Kirchoff migration software that can be used to process small-aperture 3-component array recordings of regional earthquakes and explosions to develop images of sub- and free-surface scatterers. Essentially, the software back-projects coda energy from the recording stations into the crust from which it propagated after suppressing the primary energy. If the crustal volume contains scatterers that were excited by the primary events and these scattered phases were detected by the sensor array, this energy is collapsed in space by the migration onto the scattering loci. Although most sensor array's offer limited aperture, and thus limited spatial resolution, by considering a broadly distributed event array we can take advantage of the synthetic aperture and increase spatial resolution. We have applied this type of processing to synthetics to gauge imaging resolution. We have examined local events recorded by the Pinon Flat Broadband Array (PFBA) and used 3-Component backprojection to image a deeply buried scatterer in the vicinity of the San Andreas Fault at Moho depth. We are currently assessing the feasibility of using this software to refine regional shallow-source depth estimates.

Descriptors :   *SEISMIC DISCRIMINATION, *SEISMIC ARRAYS, COMPUTER PROGRAMS, SPATIAL DISTRIBUTION, SCATTERING, SITES, ENERGY, RESOLUTION, EXPLOSIONS, PHASE, BROADBAND, EARTH CRUST, MIGRATION, RECORDING SYSTEMS, EARTHQUAKES, GAGES.

Subject Categories : Seismic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE