|
|
||||||||
DEPARTMENT OF PHYSICS AHMADU BELLO UNIVERSITY, ZARIA, Nigeria
Abstract
Microseisms in the band 1 to 15 Hz propagate principally as multi-mode Rayleigh waves. Comparison of some previously published spectra from sites over unconsolidated sediments, with theoretical Rayleigh-wave dispersion curves shows a high correlation between observed broad spectral maxima and theoretical group-velocity minima. This gives practical support to a recent prediction of this relationship. Comparison of three-component spectra with theoretical Rayleigh-wave dispersion curves and particle motion figures shows that fine structure in the observed spectra can be correlated with changes in the particle motion figures for different Rayleigh modes. Thus both broad and fine spectral features are affected by local geology and can give useful control when inverting microseism data to obtain a seismic model. The Rayleigh wave nature of microseisms implies that direct interpretation of spectra in terms of body-wave seismic resonances of the earth is incorrect. However, since an approximate correspondence exists between theoretical group velocity minima and body-wave resonant frequencies, some spectral maxima do occur near such frequencies.
This article has been cited by other articles:
![]() |
C. B. Park and R. D. Miller Roadside Passive Multichannel Analysis of Surface Waves (MASW) Journal of Environmental & Engineering Geophysics, March 1, 2008; 13(1): 1 - 11. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. J. Chavez-Garcia, M. Rodriguez, and W. R. Stephenson An Alternative Approach to the SPAC Analysis of Microtremors: Exploiting Stationarity of Noise Bulletin of the Seismological Society of America, February 1, 2005; 95(1): 277 - 293. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. BUNGUM, S. MYKKELTVEIT, and T. Kvaerna Seismic noise in Fennoscandia, with emphasis on high frequencies Bulletin of the Seismological Society of America, December 1, 1985; 75(6): 1489 - 1513. [Abstract] [PDF] |
||||
![]() |
R. E. REINKE On the spectral correlation of Rayleigh and P-wave microseisms Bulletin of the Seismological Society of America, October 1, 1983; 73(5): 1469 - 1473. [PDF] |
||||
![]() |
R. SZELWIS Inversion of microseismic array cross spectra Bulletin of the Seismological Society of America, February 1, 1980; 70(1): 127 - 148. [Abstract] [PDF] |
||||
![]() |
M. W. ASTEN Comments on "Microtremor site analysis study at Beatty, Nevada" by L. J. Katz and R. J. Bellon Bulletin of the Seismological Society of America, October 1, 1979; 69(5): 1633 - 1635. [PDF] |
||||
![]() |
L. J. KATZ A reply Bulletin of the Seismological Society of America, October 1, 1979; 69(5): 1637 - 1639. [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |