|
|
||||||||
LAMONT GEOLOGICAL OBSERVATORY, COLUMBIA UNIVERSITY,, PALISADES, NEW YORK
Abstract
Surface waves in the 1/2-second to 12-second period range, recorded at several stations in eastern North America from the eastern Tennessee shock of June 23, 1957, are the bases for several deductions concerning the effect of sedimentary layers on continental surface wave propagation. These are: (1) The velocities of surface waves of the fundamental Love and Rayleigh modes having periods less than about 10 seconds may be strongly affected by sedimentary layers of average thickness. The decrease in velocity accounts, at least in part, for the prolongation of surface-wave trains in this period range when sedimentary layers of appreciable thickness have been traversed. (2) Higher-mode propagation for both types of surface waves is a possible explanation for the velocities, frequencies, and amplitudes of the phase Sg at moderate epicentral distances, and of its long-distance counterpart the high-frequency component of Lg. The lower-frequency components of Lg have been explained previously by other aspects of normal-mode propagation in the crust. (3) Study of dispersion of short-period surface waves can result in fairly detailed knowledge of velocity-depth relation within the sedimentary column and may also reveal information on anisotropy. (4) The results of this study must bear heavily on studies of microseism propagation. As an example, the increase of microseismic activity along the entire east coast of the United States when a storm moves onto the continental shelf may be attributed to channeling of the waves in the deep sedimentary trough beneath the shelf.
This article has been cited by other articles:
![]() |
P. C. YAO and J. DORMAN Short-period surface-wave dispersion and shallow crustal structure of central and eastern Tennessee Bulletin of the Seismological Society of America, April 1, 1992; 82(2): 962 - 979. [Abstract] [PDF] |
||||
![]() |
D. A. CARTS and G. A. BOLLINGER A regional crustal velocity model for the southeastern United States Bulletin of the Seismological Society of America, December 1, 1981; 71(6): 1829 - 1847. [Abstract] [PDF] |
||||
![]() |
G. A. BOLLINGER Attenuation of the Lg phase and the determination of mb in the southeastern United States Bulletin of the Seismological Society of America, February 1, 1979; 69(1): 45 - 63. [Abstract] [PDF] |
||||
![]() |
E. S. SODBINOW and G. A. BOLLINGER Seismic studies in central and eastern Tennessee Bulletin of the Seismological Society of America, August 1, 1978; 68(4): 1081 - 1094. [Abstract] [PDF] |
||||
![]() |
C. STEPHENS and B. L. ISACKS Toward an understanding of Sn: Normal modes of love waves in an oceanic structure Bulletin of the Seismological Society of America, February 1, 1977; 67(1): 69 - 78. [Abstract] [PDF] |
||||
![]() |
W. P. CHEN and P. MOLNAR Short-period Rayleigh-wave dispersion across the Tibetan Plateau Bulletin of the Seismological Society of America, October 1, 1975; 65(5): 1051 - 1057. [Abstract] [PDF] |
||||
![]() |
F. SCHWAB and L. KNOPOFF Surface waves on multilayered anelastic media Bulletin of the Seismological Society of America, August 1, 1971; 61(4): 893 - 912. [Abstract] [PDF] |
||||
![]() |
F. GUMPER and P. W. POMEROY Seismic wave velocities and earth structure on the African continent Bulletin of the Seismological Society of America, April 1, 1970; 60(2): 651 - 668. [Abstract] [PDF] |
||||
![]() |
G. H. SUTTON, W. MITRONOVAS, and P. W. POMEROY Short-period seismic energy radiation patterns from underground nuclear explosions and small-magnitude earthquakes Bulletin of the Seismological Society of America, April 1, 1967; 57(2): 249 - 267. [Abstract] [PDF] |
||||
![]() |
L. R. SYKES and J. OLIVER The propagation of short-period seismic surface waves across oceanic areas Part II--Analysis of seismograms Bulletin of the Seismological Society of America, October 1, 1964; 54(5A): 1373 - 1415. [Abstract] [PDF] |
||||
![]() |
W. STAUDER and G. BOLLINGER Pn velocity and other seismic studies from the data of recent southeast Missouri earthquakes Bulletin of the Seismological Society of America, April 1, 1963; 53(3): 661 - 679. [Abstract] [PDF] |
||||
![]() |
J. OLIVER A summary of observed seismic surface wave dispersion Bulletin of the Seismological Society of America, January 1, 1962; 52(1): 81 - 86. [Abstract] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |