Attenuation of Modified Mercalli intensity in New Zealand earthquakes
DOI:
https://doi.org/10.5459/bnzsee.32.2.55-89Abstract
The main result of this study is the development of attenuation expressions for Modified Mercalli intensity isoseismals in New Zealand earthquakes, in terms of magnitude Mw and source distance. Attenuation of isoseismal intensities has been modelled in a new 2-dimensional manner, i.e. in terms of three distance measures, i.e. radius a along the strike of the fault rupture, radius b normal to strike, and the mean radius c. Other factors which are included in the modelling are depth, focal mechanism, tectonic type (i.e. crustal, interface or dipping slab), and regional variations. As well as being implied in the source distance, the moderate effect of depth (to increase intensities) is modelled well with a separate linear depth term. Shallow (hc ≤ 60 km) Reverse mechanism events were found to give stronger intensities than Strike-Slip events which in tum were stronger than Normal mechanism events, the difference near source between Reverse and Normal events of Mw 7+ events being about 0.4 intensity units. Attenuation for the Central Volcanic Region and Deep events differs markedly from the Main Seismic Region. No magnitude saturation effects were found. Comparisons are made with some earlier New Zealand intensity models, and local and international peak ground acceleration attenuation models.
References
Walley, P. (1976), The estimation of earthquake risk in New Zealand, Technical Report No. 49, Department of Scientific and Industrial Research, Applied Mathematics Division.
Smith, W.D. (1978), Spatial distribution of felt intensities for New Zealand earthquakes, NZ Jnl of Geology and Geophysics, 21, 293-311. DOI: https://doi.org/10.1080/00288306.1978.10424059
Smith, W.D. (1995), A development in 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
Smith, W.D. (1995), A procedure for modelling near-field earthquake intensities, Bulletin NZ National Society for Earthquake Engineering, 28(3), 218-223. DOI: https://doi.org/10.5459/bnzsee.28.3.218-223
Matuschka, T. (1980), Assessment of seismic hazard in New Zealand, Report No. 222, Department of Civil Engineering, University of Auckland.
Dowrick, D.J. (1991), A revision of attenuation relationships for Modified Mercalli intensity in New Zealand earthquakes, Bulletin NZ National Society for Earthquake Engineering, 24(3), 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, Earthquake Engineering & Structural Dynamics, 21, 181-196. DOI: https://doi.org/10.1002/eqe.4290210301
Andrews, A.L., and Butcher, G.W. (1992), Intensity of shaking generated by large shallow New Zealand earthquakes, Bulletin NZ National Society for Earthquake Engineering, 25(4), 358-360. DOI: https://doi.org/10.5459/bnzsee.25.4.358-360
Grapes, R. and Downes, G. (1997), The 1855 Wairarapa, New Zealand, earthquake - Analysis of historical data, Bulletin NZ National Society for Earthquake Engineering, 30(4), 271-368. DOI: https://doi.org/10.5459/bnzsee.30.4.271-368
Cowan, H.A. (1991), The North Canterbury earthquake of September 1, 1888, Journal Royal Society of New Zealand, 21(1), 1-12. DOI: https://doi.org/10.1080/03036758.1991.10416105
Reyners, M.E., Institute of Geological & Nuclear Sciences (in preparation). Map published in Ref. 10.
Downes, G.L. (1995), Atlas of isoseismal maps of New Zealand, Monograph 11, Institute of Geological & Nuclear Sciences, Lower Hutt, New Zealand.
Dowrick, D.J. (1994), Damage and intensities in the magnitude 7.8 1929 Murchison, New Zealand, earthquake, Bulletin NZ National Soc. for Earthq. Eng., 27(3), 190-203.
Dowrick, D.J. (1998), Damage and intensities in the magnitude 7.8 1931 Hawke's Bay, New Zealand, earthquake, Bulletin NZ National Soc. for Earthq. Eng., 31(3), 139-163.
Downes, G.L., Dowrick, D J., Smith, E.G.C. and Berryman, K.R., The 1934 Pahiatua earthquake sequence: Analysis of observational and instrumental data. (in preparation).
Dowrick, D.J., New MM Intensity isoseismals for 12 earthquakes 1922-1942, previously available only in as Rossi-Forel conversions to MMI in Ref 12. (Work in progress).
Dowrick, DJ., Isoseismal maps for 12 earthquakes 1901-1985, not previously mapped. Also maps for Events 91, 82, 84, 85. (Work in progress).
Dowrick, D.J., Complete revisions of 15 isoseismal maps in Ref. 12, from period 1948-1990, and a revision of map for Event 83. (Work in progress).
Darby, D.J. and Beanland, S. (1992), Possible source models for the 1855 Wairarapa earthquake, New Zealand, Journal of Geophysical Research, 89, 12375-12389. DOI: https://doi.org/10.1029/92JB00567
Sykes, L., Lamont-Doherty Earth Observatory of Columbia University, Unpublished study of 1855 Wairarapa earthquake.
Anderson, H., Webb, T. and Jackson, J. (1993), Focal mechanisms of large earthquakes in the South Island of New Zealand: implications for the accommodation of Pacific-Australia plate motion, Geophysical Journal International, 115, 1032-1054. DOI: https://doi.org/10.1111/j.1365-246X.1993.tb01508.x
Webb, T.H. and Anderson, H. (1998), Focal mechanisms of large earthquakes in the North Island of New Zealand: slip partioning at an oblique active margin, Geophysical Journal International, 134, 40-86. DOI: https://doi.org/10.1046/j.1365-246x.1998.00531.x
Webb, T.H., (Institute of Geological & Nuclear Sciences, pers. comm), Unpublished focal mechanism study of Fiordland earthquake of 1993 August 10.
Reyners, M., McGinty, P. and Gledhill, K. (1998), The Ormond, New Zealand, earthquake of 1993 August 10: rupture in the mantle of the subducted Pacific plate, New Zealand Journal of Geology and Geophysics, 41, 179-185. DOI: https://doi.org/10.1080/00288306.1998.9514802
Dziewonski, A.M. et al. Centroid movement tensor solutions ....... , Physics of the Earth and Planetary Interiors, various issues.
Doser, D.I. and Webb, T.H., Source parameters of large historic (1918-1961) earthquakes, South Island, New Zealand, (submitted to Geophysical Journal International).
Doser, D.I. and Webb, T.H. (in preparation), Source parameters of large historic (1917-1961) earthquakes, North Island, New Zealand.
McGinty, P., Robinson, R., Taber, J. and Reyners, M. (1997), The 1990 Lake Tennyson earthquake sequence, Marlborough, New Zealand, New Zealand Journal of Geology and Geophysics, 40, 521-535. DOI: https://doi.org/10.1080/00288306.1997.9514781
Robinson, R. (1994), Shallow subduction tectonics and fault interaction: The Weber, New Zealand, earthquake sequence o f 1990-1992, Journal o f Geophysical Research, 99, B5, 9663-9679. DOI: https://doi.org/10.1029/93JB02452
Reyners, M., McGinty, P., Ansell, J. and Ferris, B. (1997), Movement at the plate interface in Southern Hawke's Bay; the Tikokino earthquake of 11 April 1993, Bulletin NZ National Soc. for Earthq. Eng., 30(3), 242- 251.
Reyners, M., Gledhill, K., Waters, D. (1991), Tearing of the subducted Australian plate during the Te Anau, New Zealand, earthquake o f 1998 June 3, Geophysical Journal International, 104, 105-115. DOI: https://doi.org/10.1111/j.1365-246X.1991.tb02497.x
Ansell, J. and Bannister, S. (1996), Shallow morphology of the subducted Pacific plate along the Hikurangi margin, New Zealand, Physics of the Earth and Planetary Interiors, 93, 3-20. DOI: https://doi.org/10.1016/0031-9201(95)03085-9
Anderson, H. and Webb, T. (1994) , New Zealand seismicity: patterns revealed by the upgraded national seismograph network, New Zealand Journal of Geology and Geophysics, 37, 477-493. DOI: https://doi.org/10.1080/00288306.1994.9514633
Dowrick, DJ. and Rhoades, D.A. (1998), Magnitudes of New Zealand earthquakes, Bulletin NZ National Soc. For Earthquake Eng., 31(4), 260-280.
Zhao, J.X., Dowrick, D.J. and McVerry, G.H. (1997), Attenuation of peak ground accelerations in New Zealand earthquakes, Bulletin NZ National Soc. for Earthq. Eng., 30(2), 133-158.
Hancox, G.T., Perrin, N.D. and Dellow, G.D. (1997), Earthquake-induced landsliding in New Zealand and implications for MM intensity and seismic hazard assessment, Client Report 43601B, prepared for the Earthquake Commission by Institute of Geological and Nuclear Sciences, Lower Hutt.
Akaike, H. (1974), A new look at the statistical model identification, IEEE Trans. Auto. Control, AC-19 (6), 716-723. DOI: https://doi.org/10.1109/TAC.1974.1100705
Abrahamson, N.A. and Youngs, R.R. (1992), A stable algorithm for regression analysis using the random effects model. Bulletin of the Seismological Society of America, 82, 505-510.
Rhoades, D.A. (1997), Estimation of attenuation relations for strong-motion data allowing for individual earthquake magnitude uncertainties. Bulletin of the Seismological Society of America, 87, 1674-1678.
Uhrhammer, R.A., Loper, S.J. and Romanowicz, B. (1996), Determinations of local magnitude using BDSN Broadband Records. Bulletin of the Seismological Society of America, 86, 1314-1330.
Wells, D.L. and Coppersmith, K.J. (1994), New empirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement. Bulletin of the Seismological Society of America, 84, 974-1002.
Youngs, R.R., Chiou, S. -J., Silva, W.J. and Humphrey, J.R. (1997), Strong ground motion attenuation relations for subduction zone earthquakes, Seismological Research Letters, 68(1), 58-73. DOI: https://doi.org/10.1785/gssrl.68.1.58
Spudich, P. and 10 others (1997), SEA96 - A new predictive relation for earthquake ground motions in extensional tectonic regimes, Seismological Research Letters, 68(1), 190-198. DOI: https://doi.org/10.1785/gssrl.68.1.190
Abrahamson, N.A. and Shedlock, K.M. (1997), Overview, Seismological Research Letters, 68(1), 9-23. DOI: https://doi.org/10.1785/gssrl.68.1.9
Oglesby, D.D., Archuleta, R.J. and Nielsen, S.B. (1998), Earthquakes on dipping faults: The effects of broken symmetry, Science, 280, 15 May, 1055-1059. DOI: https://doi.org/10.1126/science.280.5366.1055
Midorikawa, S. (1993), Semi-empirical estimation of peak ground acceleration from large earthquakes, Tectonophysics, 218, 287-295. DOI: https://doi.org/10.1016/0040-1951(93)90275-O
Dowrick, D.J., Berryman, K.R., McVerry, G.H. and Zhao, J.X. (1998), Earthquake hazard in Christchurch, Bulletin NZ National Soc. for Earthq. Eng., 31(1), 1-23.
