Magnitudes of New Zealand earthquakes, 1901-1993

  • D. J. Dowrick GNS Science, Lower Hutt, New Zealand
  • D. A. Rhoades GNS Science, Lower Hutt, New Zealand

Abstract

Determinations of surface-wave magnitude (Ms) are made on a consistent basis for 202 selected New Zealand earthquakes over the period 1901-1993, including most post-1942 events with local magnitude not less than 6.0 and centroid depth less than 45 km. These determinations have led to a reassessment of magnitudes and locations of some earlier events in the New Zealand Seismological Observatory Catalogue of local magnitudes (ML), in some cases with substantial revisions. The surface-wave magnitudes are compared with local magnitudes and moment magnitudes (Mw), where available, and the relations between these three variables and centroid depth are examined through regression models. The absence of surface-wave observations for some earthquakes allows an upper limit to be placed on their likely moment magnitudes. The analysis shows that estimates of Mw derived from Ms will have a standard error of about 0.15 and Mw derived from ML a standard error of about 0.3.

References

Dowrick, D.J., and E.G.C. Smith (1990). Surface-wave magnitudes of some New Zealand earthquakes 1901-1988, Bulletin N Z National Society for Earthquake Engineering, 23, 198-210. DOI: https://doi.org/10.5459/bnzsee.23.3.198-210

Dowrick, D.J. (1991). Magnitude reassessment of New Zealand earthquakes, Earthquake Engineering and Structural Dynamics, 20, 577-596. DOI: https://doi.org/10.1002/eqe.4290200606

Anderson, H., T. Webb and J. Jackson (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, 103-1054. DOI: https://doi.org/10.1111/j.1365-246X.1993.tb01508.x

Webb, T.H. and H. Anderson (1998). Focal mechanisms of large earthquakes in the North Island of New Zealand: slip partitioning at an oblique active margin, Geophysical Journal International, 134, 40-86. DOI: https://doi.org/10.1046/j.1365-246x.1998.00531.x

Dziewonski, A.M. et al. Centroid moment tensor solutions, Physics of the Earth and Planetary Interiors, various issues.

Vanek, J., A. Zatopek, V. Karnik, N. Kondorskaya, Y. Riznichenko, E. Savarenski, S. Solviev ad N. Shebalin (1962). Standardisation of Magnitude Scales, Izvestia Academy of Sciences, USSR, Geophysics Series 2: 108.

Bulletin of the International Seismological Centre (England), various issues.

Ambraseys, N.N., and C.P. Melville (1982). A History of Persian Earthquakes, Cambridge University Press.

Doser, D.I. and Webb, T.H., Source parameters of large historic (1918-1962) earthquakes, South Island, New Zealand, (submitted to Geophysical Journal International).

Downes G. L. (1995). Atlas of Isoseismal Maps of New Zealand earthquakes, Monograph 11, Institute of Geological Sciences, Lower Hutt.

Ansell, J., and S. Bannister (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 T. Webb (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

Downes, G.L., D.J. Dowrick, E.G.C. Smith, and K.R. Berryman. The 1934 Pahiatua earthquake sequence: Analysis of observational and instrumental data, (in prep.).

Doser, D.I. and Webb, T.H., Source parameters of large historic (1917-1961) earthquakes, North Island, New Zealand, (in prep.).

Rhoades, D.A., and D.J. Dowrick. (1999) Station correction analysis for surface-wave magnitudes of New Zealand earthquakes. Bulletin N.Z. National Society for Earthquake Engineering (in press). DOI: https://doi.org/10.5459/bnzsee.32.1.21-29

Kamik, V. (1969). Seismicity of the European Area, Part 1, D. Reidel Publishing Company, Dordrecht, Holland.

Ambraseys, N. N. and M. W. Free (1997). Surface-wave magnitude calibration for European region earthquakes, Journal of Earthquake Engineering, 1(1), 1-22. DOI: https://doi.org/10.1080/13632469708962359

Chambers, J. M., and T. J. Hastie (1992). Statistical Models in S, Wadsworth & Brooks/Cole, Pacific Grove, California, 608pp.

Ekstrom, G., and A. M. Dziewonski (1988). Evidence of bias in estimations of earthquake size, Nature, 332, 319-323. DOI: https://doi.org/10.1038/332319a0

Eiby, G.A. (1982). Earthquakes and tsunamis in a region of diapiric folding, Tectonophysics, 85 (3-4) Tl-T8. DOI: https://doi.org/10.1016/0040-1951(82)90095-6

Eiby, G.A. (1982). Two New Zealand tsunamis, Journal of the Royal Society of New Zealand, 12(4), 337-351. DOI: https://doi.org/10.1080/03036758.1982.10415340

Kanamori, H. (1997). The energy release in great earthquakes, Journal of Geophysical Research, 82, 2981-2987. DOI: https://doi.org/10.1029/JB082i020p02981

Hanks, T.C., and H. Kanamori (1979). A moment magnitude scale, Journal of Geophysical Research, B 84, 2348-2350. DOI: https://doi.org/10.1029/JB084iB05p02348

Published
1998-12-31
How to Cite
Dowrick, D. J., & Rhoades, D. A. (1998). Magnitudes of New Zealand earthquakes, 1901-1993. Bulletin of the New Zealand Society for Earthquake Engineering, 31(4), 260-280. https://doi.org/10.5459/bnzsee.31.4.260-280
Section
Articles

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