Estimating Local and Near-Regional Velocity and Attenuation Structure from Seismic Noise

Abstract

This paper investigates the utility of computing Time-Domain Green's Functions (TDGF) to be used for estimating velocity and attenuations structure for the purposes of nuclear explosion monitoring over local and near-regional distances. Our objective is to extend and apply the methodology of deriving TDGF for propagation between two receivers by cross correlation of seismic noise and/or coda of earthquakes observed at the receivers and concentrates on the following four tasks: (1) The specific noise spectrum of the ocean microseism needs to be accounted for and compensated for in order to be able to measure group velocities across a wider bandwidth. (2) We are investigating methods to obtain spatial variations in attenuation using ambient noise. (3) Mean-phase velocity-dispersion curves are calculated for the TUCAN seismic array in Costa Rica and Nicaragua from ambient seismic noise using two independent methods: noise cross correlation and beamforming. (4) From a data set recorded by a small-scale array (~4 km aperture).

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 2008
Accession Number
ADA487650

Entities

People

  • Jian Zhang
  • Karim G. Sabra
  • Michael C. Fehler
  • Nick Harmon
  • Peter Gerstoft
  • Steven R. Taylor
  • William A. Kuperman

Organizations

  • University of California, San Diego

Tags

Communities of Interest

  • Sensors

DTIC Thesaurus Topics

  • Broadband
  • Cross Correlation
  • Data Sets
  • Doppler Effect
  • Explosions
  • Frequency
  • Frequency Bands
  • Group Velocity
  • Measurement
  • Microseisms
  • Nuclear Explosions
  • Phase Velocity
  • Seismic Waves
  • Surface Waves
  • Time Domain
  • Two Dimensional
  • Waves

Readers

  • Acoustics.
  • Life Cycle Cost Analysis
  • Seismology