Accession Number:

ADA169554

Title:

A Computational Study of Thin Layer Effects in Shallow Seismic Refraction Surveys.

Descriptive Note:

Final rept. 1 Feb 83-1 Dec 84,

Corporate Author:

AIR FORCE WEAPONS LAB KIRTLAND AFB NM

Personal Author(s):

Report Date:

1986-05-01

Pagination or Media Count:

46.0

Abstract:

Seismic refraction surveys are a valuable tool for shallow engineering site characterization purposes. Standard refraction analysis uses first arrival time data to interpret subsurface layer velocities and thicknesses. In spite of their usefulness, refraction surveys suffer from several shortcomings. In this study, the practical influence of one of these shortcomings, the thin layer effect, was examined. Synthetic seismograms were computed, using the reflectivity method, for several thin layer models. These synthetic record sections were then treated as field data and the standard interpretation processes were performed. Significant discrepancies were observed in many cases between the true geologic model originally input to the code and the model interpreted from the synthetic record sections. Keywords Primary wavesseismic waves, Seismic refraction, Wavelength, Synthetic seismograms, Geologic models, Thin layers.

Subject Categories:

  • Seismology
  • Numerical Mathematics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE