HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) References Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by DER, Z. A. Articles by MCELFRESH, T. W. Search for Related Content GeoRef GeoRef Citation

The relationship between anelastic attenuation and regional amplitude anomalies of short-period P waves in North America

SEISMIC DATA ANALYSIS CENTER TELEDYNE GEOTECH, P.O. BOX 334, ALEXANDRIA, VIRGINIA

Abstract

P-wave attenuation (expressed in terms of t^* = T/Q, the ratio of travel time to the P-wave quality factor Q) was measured for a large number of teleseismic paths using spectral ratios for nuclear explosions in the short-period band 0.5 to 4 Hz. If these new t^* values along with other data in the literature are subdivided into two groups, one involving wave paths which descend and emerge entirely under shields or stable platforms and the other involving paths with either end of the wave path under the Western United States (WUS), a definite difference can be found between the average t^* values of the two groups. The difference in attenuation, which gives a t^* difference greater than 0.2, is sufficient to explain the fact that teleseismic events appear to be, on the average, about 0.26 units lower in magnitude when measured at WUS stations as compared to Eastern United States (EUS) stations, assuming that the observed dominant frequency of teleseismic P waves is about 1 Hz. A similar difference exists in the spectra of teleseismic short-period S waves observed in WUS relative to those seen in EUS.

The observations indicate that Q is high Q > 1500) throughout the upper mantle under shield areas while the WUS (with the possible exception of the Colorado Plateau) is underlain by a low-Q layer. If this layer coincides in vertical extent with the upper-mantle low-velocity layer, the Q there should be about one-half that of the value given by Archambeau et al. (1969). The t^* values for short-period P waves are considerably lower than those derived by the other authors from body waves in the long-period band, indicating that Q is frequency dependent and increases with frequency.

This article has been cited by other articles:

				T. ZHU, K.-Y. CHUN, and G. F. WEST High-frequency P-wave attenuation determination using multiple-window spectral analysis method Bulletin of the Seismological Society of America, August 1, 1989; 79(4): 1054 - 1069. [Abstract] [PDF]

				Z. A. DER Comments on "Average Q and yield estimates from the Pahute mesa test site" by R. W. Burger, T. Lay, and L. J. Burdick Bulletin of the Seismological Society of America, October 1, 1988; 78(5): 1834 - 1834. [PDF]

				S. E. HOUGH, J. G. ANDERSON, J. BRUNE, F. VERNON III, J. BERGER, J. FLETCHER, L. HAAR, L. HANKS, and L. BAKER Attenuation near Anza, California Bulletin of the Seismological Society of America, April 1, 1988; 78(2): 672 - 691. [Abstract] [PDF]

				M. C. WALCK Spectral estimates of teleseismic P-wave attenuation to 15 Hz Bulletin of the Seismological Society of America, April 1, 1988; 78(2): 726 - 740. [Abstract] [PDF]

				Z. DER, T. MCELFRESH, R. WAGNER, and J. BURNETTI Spectral characteristics of P waves from nuclear explosions and yield estimation Bulletin of the Seismological Society of America, April 1, 1985; 75(2): 379 - 390. [Abstract] [PDF]

				P. CHEN, O. W. NUTTLI, W. YE, and J. QIN Estimates of short-period Q values and seismic moments from coda waves for earthquakes of the Beijing and Yun-nan regions of China Bulletin of the Seismological Society of America, August 1, 1984; 74(4): 1189 - 1207. [Abstract] [PDF]

				T. LAY and D. V. HELMBERGER Body-wave amplitude and travel-time correlations across North America Bulletin of the Seismological Society of America, August 1, 1983; 73(4): 1063 - 1076. [Abstract] [PDF]

				V. F. CORMIER The effect of attenuation on seismic body waves Bulletin of the Seismological Society of America, December 1, 1982; 72(6B): S169 - S200. [Abstract] [PDF]

				R. CONSOLE and A. ROVELLI Attenuation parameters for Friuli region from strong-motion accelerogram spectra Bulletin of the Seismological Society of America, December 1, 1981; 71(6): 1981 - 1991. [Abstract] [PDF]

				D. V. HELMBERGER and D. M. HADLEY Seismic source functions and attenuation from local and teleseismic observations of the NTS events jorum and handley Bulletin of the Seismological Society of America, February 1, 1981; 71(1): 51 - 67. [Abstract] [PDF]

				Z. A. DER and T. W. MCELFRESH Time-domain methods, the values of tp* and ts* in the short-period band and regional variations of the same across the United States Bulletin of the Seismological Society of America, June 1, 1980; 70(3): 921 - 924. [PDF]

				T. C. BACHE, D. G. LAMBERT, and T. G. BARKER A source model for the March 28, 1975, Pocatello Valley earthquake from time-domain modeling of teleseismic P waves Bulletin of the Seismological Society of America, April 1, 1980; 70(2): 405 - 418. [Abstract] [PDF]

				Z. DER, E. SMART, and A. CHAPLIN Short-period S-wave attenuation under the United States Bulletin of the Seismological Society of America, February 1, 1980; 70(1): 101 - 125. [Abstract] [PDF]

				S. A. SIPKIN and T. H. JORDAN Frequency dependence of QScS Bulletin of the Seismological Society of America, August 1, 1979; 69(4): 1055 - 1079. [Abstract] [PDF]

				Z. A. DER, T. W. MCELFRESH, and C. P. MRAZEK Interpretation of short-period P-wave magnitude anomalies at selected LRSM stations Bulletin of the Seismological Society of America, August 1, 1979; 69(4): 1149 - 1160. [Abstract] [PDF]

				W. B. LEE and S. C. SOLOMON Simultaneous inversion of surface-wave phase velocity and attenuation: Rayleigh and Love waves over continental and oceanic paths Bulletin of the Seismological Society of America, February 1, 1979; 69(1): 65 - 95. [Abstract] [PDF]