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 SINGH, S. K. Articles by ALMORA, D. Search for Related Content GeoRef GeoRef Citation

Analysis of near-source strong-motion recordings along the Mexican subduction zone

INSTITUTO DE INGENIERÍA UNAM, C.U., 04510 MEXICO, D.F.
INSTITUTO DE GEOFÍSICA UNAM, C.U., 04510 MEXICO, D.F.
SEISMOLOGY LAB MACKAY SCHOOL OF MINES UNIVERSITY OF NEVADA—RENO, RENO, NEVADA 89557
DIPARTIMENTO NO. 37 IDRAULICA. TRASPORTE E STRADE UNIVERSITA DEGLI STUDI DI ROMA, VIA EUDOSSIANA, 18, 00184 ROMA, Italy

Abstract

Near-source strong motions of 64 earthquakes (3 M 8.1; 10 R 54 km) recorded above the Mexican subduction zone are analyzed to study the scaling of peak horizontal acceleration, a_max, and Fourier acceleration amplitude spectra, a(f), as a function of magnitude M. The a_max data reduced to 16 km shows clear dependence on M for M 6. For M > 6, the existing data suggests that for such events a_max does not depend on M. Observation points 16 km above the source are in the far field for earthquakes with M > 6 for the frequencies (>1 Hz) of interest here, so that for such events a(f) is easily explained in terms of Brune's source spectra modified by attenuation. The same spectra explain the a_max data when Parseval's theorem is used to obtain a_rms and the expected a_max is computed using random vibration theory (RVT). For larger earthquakes, we modify the point-source model to estimate Fourier amplitude spectra from finite sources, ignoring possible directivity effects. These spectra along with rupture duration T_d is used to compute a_rms and to estimate a_max by applying RVT. The character of the near-source recordings of 6 M 8.1 earthquakes in Mexico suggests that the assumption of stationarity over T_d is reasonable. The results from the model show that beyond M 6, the dependence of a_max on M decreases; for M > 7.5 a_max becomes essentially independent of M. The a_max and a(f) observed for M 6.5 may be interpreted in terms of this finite-source model with stress drops of 40 to 100 bars and an appropriate site attenuation parameter. From a possible M = 7.5 to 8 earthquake in the Guerrero gap the expected a_max from the finite-source model in Acapulco, corresponding to = 100 bars and = 0.023s, is roughly g.

This article has been cited by other articles:

				D. M. Boore Comparing Stochastic Point-Source and Finite-Source Ground-Motion Simulations: SMSIM and EXSIM Bulletin of the Seismological Society of America, December 1, 2009; 99(6): 3202 - 3216. [Abstract] [Full Text] [PDF]

				A. Iglesias, S. K. Singh, M. Ordaz, M. A. Santoyo, and J. Pacheco The Seismic Alert System for Mexico City: An Evaluation of Its Performance and a Strategy for Its Improvement Bulletin of the Seismological Society of America, October 1, 2007; 97(5): 1718 - 1729. [Abstract] [Full Text] [PDF]

				D. Motazedian and G. M. Atkinson Stochastic Finite-Fault Modeling Based on a Dynamic Corner Frequency Bulletin of the Seismological Society of America, June 1, 2005; 95(3): 995 - 1010. [Abstract] [Full Text] [PDF]

				Estimation of Ground Motion for Bhuj (26 January 2001; Mw 7.6) and for Future Earthquakes in India Bulletin of the Seismological Society of America, February 1, 2003; 93(1): 353 - 370.

				Reply to Comment by R. A. W. Haddon on "Evaluation of Models for Earthquake Source Spectra in Eastern North America" by Gail M. Atkinson and David M. Boore Bulletin of the Seismological Society of America, October 1, 2000; 90(5): 1339 - 1341.

				Source Time Function and Duration of Mexican Earthquakes Bulletin of the Seismological Society of America, April 1, 2000; 90(2): 468 - 482.

				S. K. Singh, M. Ordaz, R. S. Dattatrayam, and H. K. Gupta A spectral analysis of the 21 May 1997, Jabalpur, India, earthquake (Mw = 5.8) and estimation of ground motion from future earthquakes in the Indian shield region Bulletin of the Seismological Society of America, December 1, 1999; 89(6): 1620 - 1630. [Abstract] [PDF]

				S. K. Singh, M. Ordaz, T. Mikumo, J. Pacheco, C. Valdes, and P. Mandal Implications of a composite source model and seismic-wave attenuation for the observed simplicity of small earthquakes and reported duration of earthquake initiation phase Bulletin of the Seismological Society of America, October 1, 1998; 88(5): 1171 - 1181. [Abstract] [PDF]

				G. L. Molas and F. Yamazaki Attenuation of earthquake ground motion in Japan including deep focus events Bulletin of the Seismological Society of America, October 1, 1995; 85(5): 1343 - 1358. [Abstract] [PDF]

				J. R. Humphrey Jr. and J. G. Anderson Seismic source parameters from the Guerrero subduction zone Bulletin of the Seismological Society of America, December 1, 1994; 84(6): 1754 - 1769. [Abstract] [PDF]

				J. G. Anderson and Y. Lei Nonparametric description of peak acceleration as a function of magnitude, distance, and site in Guerrero, Mexico Bulletin of the Seismological Society of America, August 1, 1994; 84(4): 1003 - 1017. [Abstract] [PDF]

				J. R. HUMPHREY Jr. and J. G. ANDERSON Shear-wave attenuation and site response in Guerrero, Mexico Bulletin of the Seismological Society of America, August 1, 1992; 82(4): 1622 - 1645. [Abstract] [PDF]

				C. GUTIERREZ and S. KRISHNA SINGH A site effect study in Acapulco, Guerrero, Mexico: Comparison of results from strong-motion and microtremor data Bulletin of the Seismological Society of America, April 1, 1992; 82(2): 642 - 659. [Abstract] [PDF]

				M. ORDAZ and S. KRISHNA SINGH Source spectra and spectral attenuation of seismic waves from Mexican earthquakes, and evidence of amplification in the hill zone of Mexico City Bulletin of the Seismological Society of America, February 1, 1992; 82(1): 24 - 43. [Abstract] [PDF]

				J. LOMNITZ-ADLER and F. LUND The generation of quasi-dynamical accelerograms from large and complex seismic fractures Bulletin of the Seismological Society of America, February 1, 1992; 82(1): 61 - 80. [Abstract] [PDF]

				C. J. REBOLLAR, L. MUNGUIA, A. REYES, A. URIBE, and O. JIMENEZ Estimates of shallow attenuation and apparent stresses from aftershocks of the Oaxaca earthquake of 1978 Bulletin of the Seismological Society of America, February 1, 1991; 81(1): 99 - 108. [Abstract] [PDF]