Bulletin of the Seismological Society of America
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Bulletin of the Seismological Society of America; June 1969; v. 59; no. 3; p. 1307-1334
© 1969 Seismological Society of America
This Article
Right arrow Full Text (PDF)
Right arrow References
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by MCGARR, A.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation

Amplitude variations of Rayleigh waves—horizontal refraction

ARTHUR MCGARR

LAMONT GEOLOGICAL OBSERVATORY OF COLUMBIA UNIVERSITY, PALISADES, NEW YORK 10964

Abstract

Amplitudes of the vertical component of ground motion caused by Rayleigh waves with periods of about 20 sec were measured over an array consisting of the 25 stations of the WWSSN in the United States; the Rayleigh waves were produced by shocks in selected regions of the Pacific and one area along the Mid-Atlantic Ridge. Amplitudes were plotted as a function of azimuth from epicenter to station and on outline maps centered on the epicenters. Patterns of amplitude measured by the array are highly sensitive to epicentral location; a pattern appears to change continuously with change in epicenter. The amplitudes generally show variations of a factor of 10 or more within the array. These striking fluctuations of amplitude appear to be caused by focusing due to lateral variations in phase velocity; they cannot be explained by other factors such as an asymmetrical radiation pattern at the source. Analysis based on a simple model of a horizontal variation in phase velocity yields theoretical amplitude patterns that explain the size and character of the most prominent variations in amplitude. The most marked fluctuations in amplitude here presented can be explained as the effect of regions of horizontally varying phase velocity that coincide with obvious features in the Pacific, notably, the island of Hawaii.

Amplitudes of long-period P waves appear to vary about one-fourth as much as those of Rayleigh waves in the array.




This article has been cited by other articles:


Home page
 Bulletin of the Seismological Society of AmericaHome page
R. E. Abercrombie
Regional bias in estimates of earthquake MS due to surface-wave path effects
Bulletin of the Seismological Society of America, April 1, 1994; 84(2): 377 - 382.
[Abstract] [PDF]

Home page
 Bulletin of the Seismological Society of AmericaHome page
R. J. WETMILLER, J. ADAMS, F. M. ANGLIN, H. S. HASEGAWA, and A. E. STEVENS
Aftershock sequences of the 1982 Miramichi, New Brunswick, earthquakes
Bulletin of the Seismological Society of America, April 1, 1984; 74(2): 621 - 653.
[Abstract] [PDF]

Home page
 Bulletin of the Seismological Society of AmericaHome page
P. A. SOBEL and D. H. VON SEGGERN
Applications of surface-wave ray tracing
Bulletin of the Seismological Society of America, October 1, 1978; 68(5): 1359 - 1379.
[Abstract] [PDF]

Home page
 Bulletin of the Seismological Society of AmericaHome page
S. GREGERSEN and L. E. ALSOP
Mode conversion of Love waves at a continental margin
Bulletin of the Seismological Society of America, December 1, 1976; 66(6): 1855 - 1872.
[Abstract] [PDF]

Home page
 Bulletin of the Seismological Society of AmericaHome page
B. J. MITCHELL, L. W. B. LEITE, Y. K. YU, and R. B. HERRMANN
Attenuation of Love and Rayleigh waves across the Pacific at periods between 15 and 110 seconds
Bulletin of the Seismological Society of America, August 1, 1976; 66(4): 1189 - 1202.
[Abstract] [PDF]

Home page
 Bulletin of the Seismological Society of AmericaHome page
S. GREGERSEN and L. E. ALSOP
Amplitudes of horizontally refracted Love waves
Bulletin of the Seismological Society of America, June 1, 1974; 64(3-1): 535 - 553.
[Abstract] [PDF]

Home page
 Bulletin of the Seismological Society of AmericaHome page
L. REITER
Reflection, refraction and mode conversion of long-period surface waves and the measurement of Q-1 for free oscillations
Bulletin of the Seismological Society of America, October 1, 1973; 63(5): 1709 - 1722.
[Abstract] [PDF]

Home page
 Bulletin of the Seismological Society of AmericaHome page
L. A. DRAKE
Rayleigh waves at a continental boundary by the finite element method
Bulletin of the Seismological Society of America, October 1, 1972; 62(5): 1259 - 1268.
[Abstract] [PDF]

Home page
 Bulletin of the Seismological Society of AmericaHome page
J. CAPON
Analysis of Rayleigh-wave multipath propagation at LASA
Bulletin of the Seismological Society of America, October 1, 1970; 60(5): 1701 - 1731.
[Abstract] [PDF]

Home page
 Bulletin of the Seismological Society of AmericaHome page
R. PIERMATTEI and A. A. NOWROOZI
Dispersion of Rayleigh waves for purely oceanic paths in the Pacific
Bulletin of the Seismological Society of America, October 1, 1969; 59(5): 1905 - 1925.
[Abstract] [PDF]

Home page
 Bulletin of the Seismological Society of AmericaHome page
A. MCGARR
Amplitude variations of Rayleigh waves--propagation across a continental margin
Bulletin of the Seismological Society of America, June 1, 1969; 59(3): 1281 - 1305.
[Abstract] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1969 by the Seismological Society of America.