Overview of strong-motion data from the Darfield earthquake

  • Jim Cousins GNS Science, Lower Hutt, New Zealand
  • Graeme H. McVerry GNS Science, Lower Hutt, New Zealand

Abstract

The Darfield earthquake of 3rd September 2010 UT and its aftershocks have yielded New Zealand’s richest set of strong-motion data since recording began in the early 1960s. Main-shock accelerograms were returned by 130 sites, ten of which had peak horizontal accelerations in the range 0.3 to 0.82g. One near-fault record, from Greendale, had a peak vertical acceleration of 1.26g. Eighteen records showed peak ground velocities exceeding 0.5 m/s, with three of them exceeding 1 m/s. The records included some with strong long-period directivity pulses, some with other long-period components that were related to a mixture of source and site effects, and some that exhibited the effects of liquefaction at their sites. There were marked differences between records on the deep alluvium of Christchurch City and the Canterbury Plains, and those on shallow stiff soil sites. The strong-motion records provide the opportunity to assess the effects of the earthquake in terms of the ground motions and their relationship to design motions. They also provide an invaluable set of near-source motions for seismological studies. Our report presents an overview of the records and some preliminary findings derived from them.

References

Gledhill, K., Ristau, J., Reyners, M., Fry, B. Holden, C. and the GeoNet Team (2010), “The Darfield (Canterbury) earthquakes of September 2010; preliminary seismological report”, Bulletin of the New Zealand Society for Earthquake Engineering, 43(4), this issue. DOI: https://doi.org/10.5459/bnzsee.43.4.215-221

Beavan, J., Samsonov, S., Motagh, M., Wallace, L., Ellis, S. and Plamer, N. (2010), “The Darfield (Canterbury) earthquakes: geodetic observations and preliminary source model”, Bulletin of the New Zealand Society for Earthquake Engineering, 43(4), this issue. DOI: https://doi.org/10.5459/bnzsee.43.4.228-235

Quigley, M., Van Dissen, R., Villamor, P., Litchfield, N., Barrell, D., Furlong, K., Stahl, T., Duffy, B., Bilderback, E., Noble, D., Townsend, D., Begg, J., Jongens, R., Ries, W., Claridge, J., Klahn, A., Mackenzie, H., Smith, A., Hornblow, S., Nicol, R., Cox, S., Langridge, R. and Pedley, K. (2010), “Surface rupture of the Greendale Fault during the Darfield (Canterbury) earthquake: initial findings”, Bulletin of the New Zealand Society for Earthquake Engineering, 43(4) this issue. DOI: https://doi.org/10.5459/bnzsee.43.4.236-242

Zhao, J. (2010), “More detailed ground motion data”, http://db.nzsee.org.nz:8080/en/web/lfe-darfield-2010/seismology

Standards New Zealand (2004), NZS1170.5:2004, Structural Design Actions, Part 5: Earthquake actions – New Zealand.

McVerry, G.H., Zhao, J.X., Abrahamson, N.A. and Somerville, P.G. (2006), “New Zealand acceleration response spectrum attenuation relations for crustal and subduction zone earthquakes”, Bulletin of the New Zealand Society for Earthquake Engineering 39(1): 1- 58.

McVerry, G.H. (2003), “From hazard maps to code spectra for New Zealand”, Paper No. 034, Proceedings of the 2003 Pacific Conference on Earthquake Engineering, 13-15 February 2003, Christchurch, New Zealand (published as CD-ROM).

Berrill, J.B., Davis, R.O. and McCahon, I.F. (1993), “Christchurch seismic hazard pilot study”, Bulletin of the New Zealand National Society for Earthquake Engineering 26(1): 14-27.

Brown, L.J. and Weeber, J. H. (1992), “Geology of the Christchurch urban area. Scale 1:25 000. Institute of Geological & Nuclear Sciences geological map 1”. 1 sheet + 104 p. Institute of Geological & Nuclear Sciences Limited, Lower Hutt, New Zealand.

Published
2010-12-31
How to Cite
Cousins, J., & McVerry, G. H. (2010). Overview of strong-motion data from the Darfield earthquake. Bulletin of the New Zealand Society for Earthquake Engineering, 43(4), 222-227. https://doi.org/10.5459/bnzsee.43.4.222-227
Section
Articles

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