A model for the attenuation of peak ground acceleration in New Zealand earthquakes based on seismograph and accelerograph data
A combination of weak-motion velocity data from seismographs and strong-motion acceleration data from accelerographs has been used to model the attenuation of peak ground acceleration (PGA) in New Zealand earthquakes. The resulting model extends the PGA attenuation model of Zhao, Dowrick and McVerry  to include the variability of rock strength, and also describes the unusually high attenuation in the volcanic zone of the North Island of New Zealand.
Strong-rock sites were found to experience lower PGAs than either weak rock or soil sites for magnitudes below Mw 7, and the apparent degree of amplification on going from strong rock to weak rock or soil decreased as the magnitude increased from Mw 5 to Mw 7. At magnitude 7 the PGAs were very similar for all site classes for source distances up to 100 km. When extrapolated to magnitudes beyond the maximum of the data, Mw 7.4, the model predicted that PGAs for strong rock sites were greater than for weak rock or soil sites.
The so-called "whole Taupo Volcanic Zone" was found to provide a good boundary for the zone of high attenuation in the volcanic region of the North Island. The high attenuation was successfully modelled as a simple function of the length of travel path through the zone of high attenuation. Over the effective maximum volcanic path length of about 70 km the extra attenuation resulted in a factor of ten reduction in PGA compared with non-volcanic paths of the same length.
Abercrombie, R.E. and Benites, R.A. (1998), Strong- motion modelling of the 1993 Tikokino earthquake, Southern Hawke's Bay, New Zealand. NZ J Geology and Geophysics 41:259-270. DOI: https://doi.org/10.1080/00288306.1998.9514809
Abrahamson, N. and Silva, W. (1996), Empirical response spectra attenuation relations for shallow crustal earthquakes. Seismological Research Letters 68(1): 94-117.
Borcherdt, R.D. (1994), Estimates of site-dependent response spectra for design (methodology and justification), Earthquake Spectra, 10(4), 617-653. DOI: https://doi.org/10.1193/1.1585791
Campbell, K.W. (1997), Empirical near-source attenuation relationships for horizontal and vertical components of peak ground acceleration, peak ground velocity, and pseudo-absolute acceleration response spectra. Seismological Research Letters 68(1): 154-179. DOI: https://doi.org/10.1785/gssrl.68.1.154
Campbell, K.W. and Bozorgnia, Y. (1994), Near- source attenuation of peak horizontal acceleration from world-wide accelerograms recorded from 1957 to 1993. Proc. Fifth U.S. National Conference on Earthquake Engineering, Chicago.
Cousins, W.J., Porritt, T.E., Hefford, R.T., Baguley, D.E., O'Kane, S.M. and McVerry, G.H. (1993), Computer analyses of New Zealand earthquake accelerograms 8: the Tikokino, Fiordland, and Ormond earthquakes of 1993, Institute of Geological & Nuclear Sciences, Science Report 94/33, 316p.
Cousins, W.J., Hefford, R.T., Baguley, D.E., O'Kane, S.M., McVerry, G.H. and Porritt, T.E. (1995), Computer analyses of New Zealand earthquake accelerograms, 9: the Arthur's Pass earthquake of 18 June 1994, Institute of Geological & Nuclear Sciences, Science Report 95/32, 79p.
Cousins, W.J., Perrin, N.D., McVerry, G.H., Hefford, R.T. and Porritt, T.E. (1996), Ground conditions at strong-motion recording sites in New Zealand, Institute of Geological & Nuclear Sciences, Science Report 96/33, 244p.
Cousins, W.J. and McVerry, G.H. (1997), Peak accelerations, velocities and displacements from New Zealand earthquake accelerograms, Institute of Geological & Nuclear Sciences, Science Report 97/10, 62p.
Downes, G.L. (1995), Atlas of isoseismal maps of New Zealand. Monograph 11, Institute of Geological & Nuclear Sciences, Lower Hutt.
Dowrick, DJ and Rhoades, D.A. (1999), Attenuation of Modified Mercalli Intensity in New Zealand earthquakes, Bulletin NZ Society for Earthquake Engineering, 32(2), 55-89. DOI: https://doi.org/10.5459/bnzsee.32.2.55-89
Gledhill, K.R. (1991), EARSS user's manual, Geophysics Division Technical Report No. 109, DSIR Geology and Geophysics, Wellington.
Haines, A.J. (1981), A local magnitude scale for New Zealand earthquakes, Bulletin Seismological Society of America, 71(1), 275-294.
Hefford, R.T., Tyler, R.G. and Skinner, R.I. (1980), The MO2A strong-motion accelerograph, Bulletin NZ National Society for Earthquake Engineering, 13(4), 374-379.
Hodder, S.B. (1983), Computer processing of New Zealand strong-motion accelerograms, Bulletin NZ National Society for Earthquake Engineering, 16(3), 234-246.
Joyner, W.B. and Boore, D.M. (1981), Peak horizontal acceleration and velocity from strong- motion records including records from the 1979 Imperial Valley, California, earthquake. Bulln. Seismological Society of America 71: 2011-2038.
Mark Products U.S., Inc. Product data sheet.
Maunder, D.E. (Ed.) (1997), New Zealand seismological report 1995, Seismological Observatory Bulletin E-177, Institute o f Geological & Nuclear Sciences, Science Report 97112, 279p.
McGarr, A. (1982), Upper bounds on near-source peak ground motion based on a model of inhomogeneous faulting, Bulletin Seismological Society of America, 72(6), 1825-1841.
McVerry, G.H. (1997), Near-fault earthquake records and implications for design motions, Proceedings, Technical Conference and AGM, 14-16 March 1997, Wairakei, NZ National Society for Earthquake Engineering, 88-95.
McVerry, G.H. Attenuation of acceleration response spectra in New Zealand earthquakes. [work in progress]
National Earthquake Hazard Reduction Program (1995), 1994 Recommended Provisions for Seismic Regulations of New Buildings: Part 1, Provisions. Issued by Federal Emergency Management Agency, FEMA 222A, 290pp.
NZS4203:1992, Code of practice for general structural design and design loadings for buildings, Standards New Zealand, Wellington.
Pancha, A. and Taber, J.J. (1997), Attenuation of weak ground motions, Report prepared for the New "Zealand Earthquake Commission, School of Earth Sciences, Victoria University of Wellington, August.
Skinner, R.I. and Stephenson, W.R. (1973), Accelerograph calibration and accelerogram correction, Earthquake Engineering and Structural Dynamics, 2, 71-86. DOI: https://doi.org/10.1002/eqe.4290020107
Smith, W.D. (1995), A development in the modelling of far-field intensities for New Zealand earthquakes, Bulletin NZ National Society for Earthquake Engineering, 28(3), 196-217. DOI: https://doi.org/10.5459/bnzsee.28.3.196-217
Wilson, CJ.N., Houghton, B.F., McWilliams, M.O., Lanphere, M.A., Weaver, S.D. and Briggs, R.M. (1995), Volcanic and structural evolution of Taupo Volcanic Zone, New Zealand: a review. J. Volcanology and Geothermal Research 68: 1-28. DOI: https://doi.org/10.1016/0377-0273(95)00006-G
Yetton, M.D., Wells, A and Traylen, NJ. (1998), The probability and consequences of the next Alpine Fault earthquake. Research Report 95/193, Earthquake Commission.
Youngs, R.R., Abrahamson, N., Makdisi, F. and Sadigh, K. (1995), Magnitude-dependent variance of peak ground acceleration. Bulletin Seismological Society of America 85(4): 1161-1176.
Zhao, J.X., Dowrick, DJ. and McVerry, G.H. (1997), Attenuation of peak ground accelerations in New Zealand earthquakes, Bulletin NZ National Society for Earthquake Engineering, 30(2), 133-158. DOI: https://doi.org/10.5459/bnzsee.30.2.133-158
Copyright (c) 1999 W. J. Cousins, J. X. Zhao, N. D. Perrin
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