A development in the modelling of far-field intensities for
 New Zealand earthquakes

Authors

  • W. D. Smith GNS Science, Lower Hutt, New Zealand

DOI:

https://doi.org/10.5459/bnzsee.28.3.196-217

Abstract

With the availability of better estimates of magnitudes for large historical earthquakes, a 1978 study to model the Modified Mercalli intensities in large earthquakes in New Zealand has been revised. While instrumental measures of strong ground motion are obviously valuable, intensities will always be important because most of our large historical events predate the installation of accelerographs, and because intensity does seem to give a measure of the degree of damage.

Crustal earthquakes in the Main Seismic Region have been divided into two classes on the basis of known or apparent focal depth. Events in the volcanic region are treated separately. No revision is attempted for shallow earthquakes in Fiordland or for events at greater than crustal depths anywhere in the country, the data base being too poor. Detailed goodness-of-fit statistics are presented: they compare favourably with those for the 1978 model and also for another model developed recently. The model is for the far field, so is useful for regional estimation of hazard but not for fault-specific studies at short distances. A companion paper addresses near-source modelling.

Intensity is often assumed to be linearly related to the logarithm of ground motion parameters such as displacement or acceleration. This study shows that that assumption cannot hold over a range of distances. It may be possible to formulate a linear relationship at any particular distance, but the parameters of that relationship will change as distance is varied.

References

Anderson, Helen; Webb, Terry, 1989. The rupture process of the Edgecumbe earthquake, New Zealand. N.Z. J. Geol. Geophys. 32:43-52. DOI: https://doi.org/10.1080/00288306.1989.10421387

Anderson, Helen; Webb, Terry and Jackson, James 1993. Focal mechanisms of large earthquakes in the South Island, New Zealand; implications for the accommodation of Pacific-Australia plate motion. Geophys. J. Int. 115: 1032-1054. DOI: https://doi.org/10.1111/j.1365-246X.1993.tb01508.x

Boore, D.M.; Joyner, W.B.; Furnal, T.E. 1993. Estimation of response spectra and peak accelerations from Western North American earthquakes: an interim report. U.S. Geological Survey Open-File Report 93-509, 72 pp. DOI: https://doi.org/10.3133/ofr93509

Brekhovskikh, L.M. 1960. Waves in layered media, translated by D. Lieberman, New York, Academic Press.

Darby, D.J. and Beanland, S. 1992. Possible source models for the 1855 Wairarapa earthquake. J. Geophys. Res. 97(12): 375-12,389.

Davey, F.J. and Smith, E.G.C. 1983. The tectonic setting of the Fiordland region, south-west New Zealand. Geophys. J. R. astr. Soc. 72:23-38. DOI: https://doi.org/10.1111/j.1365-246X.1983.tb02802.x

Dowrick, D.J. 1991. Magnitude reassessment of New Zealand earthquakes. Earthq. Engng. Struct. Dynamics. 20:577-596. DOI: https://doi.org/10.1002/eqe.4290200606

Dowrick, D.J. 1991. A revision of attenuation relationships for Modified Mercalli intensity in New Zealand earthquakes. Bull. N.Z. Nat. Soc. Earthq. Engng. 24:210-224. DOI: https://doi.org/10.5459/bnzsee.24.3.210-224

Dowrick, D.J. 1992. Attenuation of Modified Mercalli intensity in New Zealand earthquakes. Earthq. Engng. Struct. Dynamics. 21:181-196. DOI: https://doi.org/10.1002/eqe.4290210301

Dowrick. D.J. 1994. Damage and intensities in the magnitude 7.8 1929 Murchison, New Zealand, earthquake. Bull. N.Z. Nat. Soc. Earthq. Engng. 27:190-204.

Dowrick, D.J. and Smith, E.G.C. 1990. Surface wave magnitudes of some New Zealand earthquakes 1901-1988. Bull. N.Z. Nat. Soc. Earthq. Engng. 23: 198-210. DOI: https://doi.org/10.5459/bnzsee.23.3.198-210

Dziewonski, A.M., Friedman, A. Giardini D . Woodhouse, J. H. 1983. Global seismicity of 1982: centroid-moment tensor solutions for 308 earthquakes. Phys. Earth Planet. Int. 33:76-90. DOI: https://doi.org/10.1016/0031-9201(83)90141-3

Dziewonski. A.M., Franzen, J.E., Woodhouse, J.H. 1984. Centroid-moment tensor solutions for Jan-Mar 1984. Phys. Earth Planet. Int. 34:209-219. DOI: https://doi.org/10.1016/0031-9201(84)90062-1

Dziewonski, A.M., Ekstrom, G., Franzen, J.E., Woodhouse, J.H. 1987. Global seismicity of 1977: centroid-moment tensor solutions for 471 earthquakes. Phys. Earth Planet. Int. 45:11-36 DOI: https://doi.org/10.1016/0031-9201(87)90194-4

Dziewonski, A.M., Ekstrom, G., Woodhouse, J.H., Zwart, G. 1988. Centroid-moment tensor solutions for January-March 1987. Phys. Earth Planet. Int. 50:116-126. DOI: https://doi.org/10.1016/0031-9201(88)90002-7

Dziewonski, A.M., Ekstrom, G., Woodhouse, J.H., Zwart. G. 199 la. Centroid-moment tensor solutions for January-March 1990. Phys. Earth Planet. Int. 65:197-206. DOI: https://doi.org/10.1016/0031-9201(91)90127-4

Dziewonski, A.M., Ekstrom, G., Woodhouse, J.H., Zwart, G. 1991b. Centroid-moment tensor solutions for April-June 1990. Phys. Earth Planet. Int. 66:133-143. DOI: https://doi.org/10.1016/0031-9201(91)90072-P

Eiby, G.A. 1971. Seismic regions of New Zealand. Roy. Soc. N.Z. Bull. 9: 153-160.

Eiby, G. A. 1977. Anomalous intensities due to the Korakonui earthquake, 5 December 1976. Bull. N.Z. Nat. Soc. Earthq. Engng. 10:167-169.

Haines, A.J. 1981. A local magnitude scale for New Zealand earthquakes. Bull. Seism. Soc. Am. 71:275-294.

Hamilton, R.M. 1969. Seismological Studies of the Gisborne earthquake sequence 1966. Gisborne Earthquake, New Zealand, March 1966, NZ DSIR Bull 194. 7-23.

Hamilton, R.M. and Evison, F.F. 1967. Earthquakes at intermediate depths in South-West New Zealand. N.Z. J. Geol. Geophys. 10:1319-1329. DOI: https://doi.org/10.1080/00288306.1967.10423218

Hanks, T.C. and Kanamori, H. 1979. A moment magnitude scale. J. Geophys. Res. 84:2348-2350. DOI: https://doi.org/10.1029/JB084iB05p02348

Hayes, R.C. 1936. Intensity distribution in New Zealand earthquakes. N.Z. Journal of Science and Technology. 18:508-11.

Joyner, W.B. and Boore, D.M. 1988. Measurement, characterization and prediction of strong ground motion. In, Earthquake Engineering and Soil Dynamics 11 - Recent Advances in Ground Motion Evaluation, Geotechnical Special Publication No. 20, ASCE, New York, pp. 43-102.

Matuschka, T. 1980. Assessment of seismic hazards in New Zealand. Dept. of Civil Engineering Res. Report No. 222, University of Auckland, New Zealand.

Reyners, Martin and Cowan, Hugh 1993. The transition from subduction to continental collision: crustal structure in the North Canterbury region, New Zealand. Geophys. J. Int. 115: 1124-1136. DOI: https://doi.org/10.1111/j.1365-246X.1993.tb01514.x

Robinson, R. 1991. The use of neural-networks as an alternative to traditional regression. GEOBITE. 6:14-19.

Smith, W.D. 1976. Statistical Estimates of the Likelihood of Earthquake Shaking Throughout New Zealand. Bull. N.Z. Nat. Soc. Earthq. Engng. 9:213-221.

Smith, W.D. 1977. The Importance of Surface Waves in Strong Ground Motion. Bull. N.Z. Nat. Soc. Earthq. Engng. 10:170-173.

Smith, W.D. 1978a. Spatial Distribution of Felt Intensities for New Zealand Earthquakes. N.Z. J. Geol. Geophys. 21:293-311. DOI: https://doi.org/10.1080/00288306.1978.10424059

Smith, W.D. 1978b. Earthquake Risk in New Zealand: Statistical Estimates. N.Z. J. Geol. Geophys. 21:313-327. DOI: https://doi.org/10.1080/00288306.1978.10424060

Smith. W.D. 1990. Earthquake hazard in New Zealand: some implications of the Edgecumbe earthquake, March 1987. Bull. N.Z. Nat. Soc. Earthq. Engng. 23:211-219.

Smith, W.D. 1995. A Procedure for Modelling Near-Field Earthquake Intensities. Bull. N.Z. Nat. Soc Earthq Engng. 28(3)·218-223 (This issue). DOI: https://doi.org/10.5459/bnzsee.28.3.218-223

Smith, W.D. and Berryman, K.R. 1983. Revised Estimates of Earthquake Hazard in New Zealand. Bull. N.Z. Nat. Soc. Earthq. Engng. 16:259-272.

Smith, W.D. and Berryman. K.R. 1986. Earthquake Hazard in New Zealand: Inferences from Seismology and Geology Roy. Soc. N.Z. Bull. 24:223-243.

Walley, P 1976. The estimation of earthquake risk in New Zealand. Applied Mathematics Division Technical Report No. 49., DSIR, Wellington.

Wiggins, R.A. 1976. Interpolation of digitized curves. Bull. Seism. Soc. Am. 66:2077-2081.

Yang, Jiushan 1991. The Kakapo Fault - a major active dextral fault in the central North Canterbury-Buller regions of New Zealand. N.Z. J. Geol. Geophys. 34: 137-143. DOI: https://doi.org/10.1080/00288306.1991.9514451

Downloads

Published

30-09-1995

How to Cite

Smith, W. D. (1995). A development in the modelling of far-field intensities for
 New Zealand earthquakes. Bulletin of the New Zealand Society for Earthquake Engineering, 28(3), 196–217. https://doi.org/10.5459/bnzsee.28.3.196-217

Issue

Section

Articles

Categories