The 1942 Wairarapa, New Zealand, earthquakes

Analysis of observational and instrumental data

  • G.L. Downes GNS Science, Lower Hutt, New Zealand
  • D.J. Dowrick GNS Science, Lower Hutt, New Zealand
  • R.J. Van Dissen GNS Science, Lower Hutt, New Zealand
  • J.J. Taber Victoria University of Wellington, Wellington, NZ
  • G.T. Hancox GNS Science, Lower Hutt, New Zealand
  • E.G.C. Smith Victoria University of Wellington, Wellington, NZ

Abstract

In 1942, two large earthquakes, on June 24 (Mw 7.2) and August 1 (UT) (Mw 6.8), strongly shook the lower North Island, causing widespread moderate to severe damage. A third earthquake (Ms 6.0) occurred in the same area on December 2.

These earthquakes have now been studied in detail by re-analysing seismograms from 1942 and by the collection and analysis of contemporary technical information and descriptive accounts from many sources. Results include new locations for the three main earthquakes and other moderate magnitude earthquakes in the sequence, summaries of building, lifelines and ground damage, new isoseismal maps and maps showing the distribution of landslides, liquefaction and other ground damage. The study has provided valuable information on the performance of buildings and lifelines in urban and small town environments at high intensities (MM8) and on the distribution of damaged buildings in central Wellington in relation to published ground shaking hazard microzoning maps and foreshore reclamation units.

An important result is that scarp-like features described after the June earthquake as surface fault rupture are probably landslide-related rather than tectonically produced. This result and the lack of evidence for any other surface fault rupture, the closeness in time and space of the earthquakes both within the sequence and with the 1934 Pahiatua earthquake, and the similarity of the sequence to the 1990 Weber earthquakes have important implications for seismic hazard assessment of this part of the Hikurangi Margin.

References

Dowrick, D. J., Rhoades, D. A., (1998). "Magnitudes of New Zealand earthquakes, 1901-1993". Bulletin of the New Zealand National Society for Earthquake Engineering 31: 260-280.

Gibowicz, S. J., (1973). "Variation of the frequency-magnitude relation during the 1931 Hawke's Bay, 1934 Pahiatua, and 1942 Wairarapa aftershock sequences". New Zealand journal of geology and geophysics 16: 1009-1045.

Hayes, R. C., (1942). "The Wairarapa earthquake of 24th June 1942". DSIR Dominion Observatory [New Zealand] Bulletin S-66.

Hayes, R. C., (1943b). "Earthquakes in New Zealand during the year 1942". New Zealand journal of science and technology 24: 191-194.

Hayes, R. C., (1942). (Unpublished) "Report on the reconnaissance of Wairarapa earthquake area 1942 June 26th-30th”. DSIR Dominion Observatory [New Zealand] internal report.

Ongley, M., (1943). "Wairarapa earthquake of 24th June, 1942, together with a map showing surface traces of faults recently active". New Zealand journal of science and technology B25: 67-78.

Hayes, R. C., (1943a). "Extract from the Annual Report of the Department of Scientific and Industrial Research, 1942-43". DSIR Dominion Observatory Bulletin R28.

Neef, G., (1976). (Note.) "Probable faulting on a minor, reverse bedding fault adjacent to the Alfredton Fault, north Wairarapa, during the I August 1942 earthquake". New Zealand journal for geology and geophysics 19: 737-742.

Berryman, K., (1977). "Dating recent tectonic events in parts of New Zealand with dendrochronology". Unpublished BSc (Hons) paper. Victoria University of Wellington, Wellington, New Zealand.

New Zealand journal of science and technology 15: 3-1l5 contains six papers on various aspects of the 1931 Hawke's Bay earthquake.

New Zealand journal of science and technology 18: 845- 865 contains four papers on the 1932 Wairoa earthquake.

Aked, W. E., (1945). "Damage to buildings in the City of Wellington by earthquake, 1942". Proceedings of the New Zealand Institution of Engineers 31: 132-183.

Luke, K. E., (1943). "City of Wellington, NZ. Report on damage by earthquakes, 1942". (Unpublished) City Engineers' report to Wellington City Council. Wellington City Council Archives and GNS files.

Johnston, J. A. R., (1960). "A brief history of damaging earthquakes in Wellington City and developments in multi-storey building construction in New Zealand". Proceedings of the Second World Conference on Earthquake Engineering, Tokyo and Kyoto 1: 457-471.

Grant-Taylor, T. L.; Adams, R. D.; Hatherton, T.; Milne, J. D. G.; Northey, R. D.; Stephenson, W. R., (1974): "Microzoning for earthquake effects in Wellington, N. Z." New Zealand Department of Scientific and Industrial Research Bulletin 213.

Van Dissen, R. J., Taber, J. J., Stephenson, W. R., Sritharan, S., Perrin, N. D., McVerry, G.H., Campbell, H. J., Barker, P. R., (I 992). "Earthquake ground shaking hazard assessment for Wellington City and suburbs, New Zealand". DSIR Geology & Geophysics Contract report 1992/23, prepared for the Wellington Regional Council.

Van Dissen, R. J., Taber, J. J., Stephenson, W. R., Sritharan, S., Perrin, N. D., McVerry, G.H., Campbell, H. J., Barker, P. R., (1993). "Ground shaking hazard zonation for Wellington City and suburbs, New Zealand". Conference technical papers. New Zealand National Society for Earthquake Engineering, Technical Conference and AGM, Wairakei Hotel, Taupo, 26-28 March 1993: 134-141.

Dowrick, D. J., (1996). "The Modified Mercalli earthquake intensity scale - revisions arising from recent studies of New Zealand earthquakes". Bulletin of the New Zealand National Society for Earthquake Engineering 29: 92-106.

Downes, G. L., (1995). "Atlas of isoseismal maps of New Zealand earthquakes". Institute of Geological & Nuclear Sciences monograph 11. Institute of Geological & Nuclear Sciences Ltd., Lower Hutt, New Zealand.

Smith, W. D., (1995). "A development in the modelling of far-field intensities for New Zealand earthquakes". Bulletin of the New Zealand National Society for Earthquake Engineering 28: 196-217.

Dowrick, D. J., (1991). "A revision of attenuation relationships for Modified Mercalli intensity in New Zealand earthquakes". Bulletin of the New Zealand National Society for Earthquake Engineering 24: 210- 224.

Dowrick, D. J., (1994). "Damage and intensities in the magnitude 7.8 1929 Murchison, New Zealand, earthquake". Bulletin of the New Zealand National Society for Earthquake Engineering 27: 190-204.

Dowrick, D. J., (1998). "Damage and intensities in the magnitude M,7.8 1931 Hawke's Bay, New Zealand, earthquake". Bulletin of the New Zealand National Society for Earthquake Engineering 31: 139-163.

Downes, G., Dowrick, D., Smith, E., Berryman, K., (1999). ''The 1934 Pahiatua earthquake sequence: analysis of observational and instrumental data". Bulletin of the New Zealand Society for Earthquake Engineering 32: 221-245.

Dowrick, D. J., Rhoades, D. A., (1999). "Attenuation of Modified Mercalli intensity in New Zealand earthquakes". Bulletin of the New Zealand National Society for Earthquake Engineering 32: 55-89.

Webb, T. H., (1989). "The 1942 Wairarapa earthquakes". Bulletin of the New Zealand Society for Earthquake Engineering 22: 33.

Webb, T. H., Doser, D. I., (1998). "Historic seismicity of the North Island, New Zealand, and its relation to oblique subduction along the Hikurangi Margin". EOS, Transactions, American Geophysical Union, 1998 Fall meeting, 79 Supplement: F904.

Dowrick, D. J., Rhoades, D. A., Babor, J., Beetham, R. D., (1995). "Damage ratios for houses and microzoning effects in Napier in the magnitude 7.8 Hawke's Bay, New Zealand, earthquake of 1931". Bulletin of the New Zealand National Society for Earthquake Engineering 28: 135-151.

Eiby, G. A., (1982). "New Zealand Seismological Report 1948-49-50". Seismological Observatory [New Zealand] Bulletin E-164.

Maunder, D. E. (ed.) (1999). "New Zealand seismological report 1997. Seismological Observatory Bulletin E0180". Institute o f Geological & Nuclear Sciences science report 99/20. 167p.

Ansell, J. H., Bannister, S. C., (1996). "Shallow morphology of the subducted Pacific plate along the Hikurangi margin, New Zealand". Physics of the Earth and Planetary Interiors 93: 3-20.

Zhao, J. X., Dowrick, D. J., McVerry, G. H., (1997). "Attenuation of peak ground accelerations in New Zealand earthquakes". Bulletin of the New Zealand National Society for Earthquake Engineering 30: 133-157.

Harris, A.G., Bums, D. J., (1942). "Earthquake damage. Borough Surveyors' [unpublished] Reports". Prepared for C.R. Mabson, Borough Engineer, on non-domestic buildings in the Borough of Masterton, 2 July & 17 July, plus addenda dated 22 August 1942. Held at Wairarapa Archives, Masterton, New Zealand.

Mabson, C.R., (1942). Letter written by the Borough Engineer to the Mayor and Councillors of Masterton regarding the effects of the earthquake of June 24. Undated, but between 17 July and 24 August. Held at Wairarapa Archives, Masterton, New Zealand.

Building Regulations Committee, (1931). Report of the Building Regulations Committee, to the House of Representatives, Wellington, 23 June 1931.

Mabson, C. R. (ca. 1939). Memo from CR Mabson to the Mayor of Masterton. Held at Wairarapa Archives, Masterton, New Zealand.

Local Government Amendment Act, 1979. New Zealand Government, Wellington.

Dowrick, D. J., (1998). "Earthquake risk for property and people in New Zealand". New Zealand National Society for Earthquake Engineering technical conference and ACM, Wairakei Hotel, Taupo, 1998: 43- 50.

Hughes, J. R., (1942). Letter on "Earthquake Damage'' from the City Engineer to Town Clerk, Palmerston North, 8 July 1942.

Fairless, G. J., Berrill, J. B., (1984). "Liquefaction during historic earthquakes in New Zealand". Bulletin of the New Zealand National Society for Earthquake Engineering 17: 280-291.

Grapes, R., Downes, G., (1997). "The 1855 Wairarapa, New Zealand, earthquake - analysis of historical data". Bulletin of the New Zealand National Society for earthquake Engineering 30: 271-368.

Hancox, G. T., Perrin, N. D., Dellow, G. D., (1997). "Earthquake-induced landslides in New Zealand and implications for MM intensity and seismic hazard assessment". CNS Client Report 43601B prepared for the Earthquake Commission, 10 December 1997.

Smith, W. D., Berryman, K. R., (1986). "Earthquake hazard in New Zealand: inferences from seismology and geology". Royal Society of New Zealand Bulletin 24: 223-243.

Stirling, M. W., Wesnousky, S. G., Berryman, K .R., (1998). "Probabilistic seismic hazard analysis of New Zealand". New Zealand Journal of geology and geophysics 41: 355-375.

Stirling, M., McVerry, G., Berryman, K., McGinty, P., Villamor, P., Van Dissen, R., Dowrick, D., Cousins, J., Sutherland, R., (2000). "Probabilistic Seismic Hazard Assessment of New Zealand: New Active Fault Data, Seismicity Data, Attenuation Relationships and Methods". Prepared for the Earthquake Commission Research Foundation. Institute of Geological & Nuclear Sciences client report 2000/53.

Fitch, T. J., (1972). "Plate convergence, transcurrent faults and internal deformation adjacent to southeast Asia and the western Pacific". Journal of Geophysical Research 77: 4432-4460.

Walcott, R. I., (1978). "Present tectonic and late Cenozoic evolution of New Zealand". Geophysical Journal of the Royal Astronomical Society 52: 137-164.40.

Van Dissen, R. J., Berryman, K. R., (1996). "Surface rupture earthquakes over the last ca 1000 years in the Wellington region, New Zealand, and implications for ground shaking hazard". Journal of Geophysical Research 101: 5999-6019.

Barnes, P. M., Mercier de Lepinay, B., (1997). "Rates and mechanics of rapid frontal accretion along the very oblique convergent southern Hikurangi margin, New Zealand". Journal of Geophysical Research 102: 24,931-24,952.

Cashman, S. M., Kelsey, H. M., Erdman, C. F., Cutten, H. N. C., Berryman, K. R., (1992). "Strain partitioning between structural domains in the forearc of the Hikurangi subduction zone, New Zealand". Tectonics 11: 242-257.

Nicol, N., Van Dissen, R. J., (1997). "Late Miocene to recent fault and fold deformation east of Martinborough, Wairarapa". Geological Society of New Zealand Miscellaneous Publication 95B, Geological Society of New Zealand Annual Conference field trip guide FT 3, November 1997, 17 p.

Reyners, M., (1998). "Plate coupling and the hazard of large subduction thrust earthquake at the Hikurangi subduction zone, New Zealand". New Zealand journal of geology and geophysics 41: 343-354.

Lensen, G. J., (1968). Sheet N158 Masterton (1st Ed.) "Late Quaternary Tectonic Map of New Zealand 1:63360". Department of Scientific and Industrial research, Wellington, New Zealand.

Cotton, C.A., (1958). Geomorphology: An introduction to the study of landforms. Whitcombe & Tombs Limited, 7th Edition, 505 pages.

Schermer, E., Van Dissen, R., Berryman, K., (1998). "In search of the source of the 1934 Pahiatua Earthquake". Final report on EQC Research Project 97/320.

Stevens, G. R., (1974). Rugged landscape. A. W. & A. H. Reed, Wellington.

Kingsbury, P.A., Hastie, W. J., (1992). "Seismic hazard map series: Ground shaking hazard, Map Sheet 1 Wellington 1:20000". Wellington Regional Council Publication No. WRCIPP-T-92145.

Perrin, N. D., Campbell, H. J., (1992). "Compilation of geological data, Wellington area". DSIR Geology and Geophysics Contract Report 1992/24 prepared for the Wellington Regional Council.

Wellington Harbour Board, (1936). "Historical Plan of reclamations in the Port of Wellington (Port Nicholson)". Compiled and drawn at the Head Office of the Wellington Harbour Board. Original held at the Maritime Museum, Queen's Wharf, Wellington.

Baillie, H., (1924). "The early reclamations and harbour works of Wellington". Transactions of the New Zealand Institute 55: 700-720.

King, G. C. P., Stein, R. S., Lin, J., (1994). "Static stress changes and the triggering of earthquakes". Bulletin of the Seismological Society of America 84: 935-953.

Robinson, R., McGinty, P., (2000). "The enigma of the Arthur's Pass, New Zealand, Earthquake, 2: The Aftershock Distribution and its relation to Regional and Induced Stress". Journal of Geophysical Research 105: 16, 139-16, 150.

McGinty, P., Darby, D., Haines, J., (2000). "Earthquake Triggering in the Hawke's Bay, New Zealand, region from 1931 to 1934 as inferred from elastic dislocation and static stress modelling". Submitted to Journal of Geophysical Research.

Robinson, R., (1994). "Shallow subduction tectonics and fault interaction: The Weber, New Zealand, earthquake sequence of 1990-1992". Journal of Geophysical Research 99: 9663-9679.

Published
2001-06-30
How to Cite
Downes, G., Dowrick, D., Van Dissen, R., Taber, J., Hancox, G., & Smith, E. (2001). The 1942 Wairarapa, New Zealand, earthquakes. Bulletin of the New Zealand Society for Earthquake Engineering, 34(2), 125-157. https://doi.org/10.5459/bnzsee.34.2.125-157
Section
Articles