INVESTIGATION OF SHORT-PERIOD SEISMIC NOISE IN MAJOR PHYSIOGRAPHIC ENVIRONMENTS OF CONTINENTAL UNITED STATES

Abstract

Measurements of spectral density levels of shortperiod seismic noise are obtained for points distributed throughout the continental United States and for a few non-North American locations. Noise amplitudes and gradients in the far field correlate on a regional basis with major physiographic provinces, as revealed by iso-particle-velocity contouring. The ensemble of space and time samples of noise is examined to illustrate the average spectrum and dispersion for three orthogonal components of ground-particle velocity in the range 0.25 to 100 cps. Probability distributions of noise amplitudes based on a collection of space averages and time averages are presented for several frequencies. The ratio of horizontal to vertical noise amplitude (H/Z) exceeds the theoretical value for simple Rayleigh waves and shows a frequency-dependent variation with regional geologic environment.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1965
Accession Number
AD0617122

Entities

People

  • G. E. Frantti

Organizations

  • University of Michigan

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Amplitude
  • Data Analysis
  • Environment
  • Field Equipment
  • Frequency
  • Geography
  • Lake Superior
  • Measurement
  • Particles
  • Probability
  • Probability Distributions
  • Rayleigh Waves
  • Spectra
  • Surface Waves
  • United States
  • Waves

Readers

  • Control Systems Engineering.
  • Seismology
  • Statistical inference.

Technology Areas

  • Space
  • Space - Space Objects