Abstract
Nearly 200 historical accounts have been examined and analysed in order to determine the effects of the magnitude 8+ 1855 Wairarapa, New Zealand, earthquake. The documents examined include contemporary diaries, letters and journals, newspaper reports and articles, archives, memoranda and reports of the Wellington Provincial Government as well as later reminiscences, extracts from published scientific papers, books and other articles. Other than the published accounts of Sir Charles Lyell, who, in 1856, first recognised the importance of the earthquake as causing the greatest deformation and surface fault rupture then known, there has been no comprehensive account of the effects of the earthquake in the scientific literature until now. Much or the data is presented with extensive quotations from the source material, especially where conflicting accounts on important aspects have been found. All material is analysed with an understanding of the geographical, social and political conditions at the time. The reliability of the material is taken account of so that first-hand accounts, that have been recorded no more than several years after the earthquake, and in which there are no obvious inconsistencies or confusion with other earthquakes, are valued most highly. Using the historical accounts as the primary source of data, but also taking into account the results of more recent geological, geomorphological and seismological investigations of the deformation, many aspects of the earthquake are discussed in detail. These are mainshock magnitude and epicentre; felt intensity distribution: descriptive account of the effects of the mainshock on people (including casualties) and man-made structures by location throughout New Zealand (including a resume of contemporary building techniques): effects on the environment from strong shaking such as fissuring, liquefaction, spreading, subsidence and landslides, and from tectonically produced uplift, subsidence and faulting; biological effects; tsunami and seiche; aftershock occurrence and social response and recovery.
Highlights
On the evening of 23 January 1855 a large earthquake shook almost the whole of New Zealand
The water level in Wellington Harbour oscillated for 8- I2 hours after the earthquake which may he explained as a response to tsunami generated external to the harbour and to seiching generated by differential uplift across the harbour and possibly by sudden horizontal displacement of the harbour perimeter accompanying right lateral slip on the Wairarapa Fault
The Nelson E.wminer (Jan 31 1855) reported that "intelligence has been received from the Wairau, and we find that the shock of the 23rd was felt very severely at the lower end of the valley ... but ascending the valley, the shocks became less severe as the distance from the sea increased". and that the ground was cracked with "sand and mud thrown up there in places"
Summary
On the evening of 23 January 1855 a large earthquake shook almost the whole of New Zealand. McKay (1901) mentions that "the earthquake of 1845(1855] which was the cause of the raised beaches along this coast [western side of Palliser Bay] according to the old settlers, did not affect the spit [the area between the Lake Onoke outlet and Kirawai] The height of these raised gravels is considerably lower than the adjoining bar of Onoke Lake, parts of it being barely above the tide". The connecting channel from the Lake, which was a considerable depth before the shake was practically dry." While this could be interpreted in terms of tectonic uplift, it could be due to lateral spreading of the sand and gravel that make up the bar as a result of earthquake shaking This would account for the disappearance of the 'deep' connecting channel between the 'backwater' mentioned by Matthews, and Lake Onoke (Fig.).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Bulletin of the New Zealand Society for Earthquake Engineering
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
