Earthquake Details
When Tue Jan 23 1855 9:11 PM
Where 20 km west of Martinborough
Shaking Extreme, at least 50 seconds
Magnitude 8.2
Depth 33 km
Casualties: 7-9 killed, 5 injured
The shock was felt across almost the whole country, and was highly destructive in Wellington (MM 10), and severely damaging in Whanganui and Kaikōura. Between 7 and 9 people were killed in the earthquake, and 5 others sustained injuries that required hospitalisation.
The earthquake originated on the Wairarapa Fault and caused extensive faulting and uplift in epicentral areas. The latter was most dramatic at Muka Muka, on the western side of Palliser Bay, where the ground was raised by 2.7m. Significant uplift also occurred in Wellington City, most noticeably around Wellington Harbour, altering the city's shoreline considerably. Today, Wellington's Basin Reserve sports ground sits on land lifted by this earthquake; the area had previously been part of a waterway that led into the harbour. The ground level at Pauatahanui, Lowry Bay, Petone, Lower Hutt and to the east of Lake Wairarapa was also raised, but it is possible that this was caused by material being deposited, rather than tectonic uplift. The Petone foreshore increased by nearly 1km. The uplift of the northwestern side of Wellington Harbour rendered many of the jetties in the harbour unusable, although this new area of land provided a new rail and road route to the north. Much of modern Wellington's central business district is formed by reclamations on land raised from the harbour by the event, as shown by the series of "Shoreline 1840" plaques.[12][13] At Turakirae Head the newest raised beach was formed by an uplift of 6.4 m (21 ft) in the 1885 quake.
The earthquake triggered extensive landsliding on both faces of the Rimutaka Ranges, along the Kaikōura coast and in Wellington, where access to Petone was cut off when a large landslide containing ~300,000 m3 of material cascaded down to block the coastal track north. The slip is still visible today along the Hutt Road. The shaking also created numerous slump cracks in flat areas of Wellington, the Hutt Valley, Wairarapa, and in the Manawatu district. In these areas the earthquake also triggered sandblows and the eruption of groundwater at the surface, liquifaction, the result of massive pressure increases underground that were caused by the shaking.
The earthquake was followed by many aftershocks, some of which were very damaging. There is strong evidence that the earthquake generated a local tsunami and it is also possible that small tsunami accompanied some aftershocks.
The 1855 earthquake is the most severe earthquake to have occurred in New Zealand since systematic European colonisation began in 1840. The shock was felt across almost the whole country, and was highly destructive in Wellington (MM 10), and severely damaging in Whanganui and Kaikōura.
Charles Ernest von Alzdorf (1815-1855) was one of the few people killed in Wellington’s massive 1855 earthquake – he was killed in his Wellington Hotel (The Commercial in Lambton Quay) by a falling brick. Charles Alzdorf (sometimes spelled Alsdorf) arrived in Wellington on the Adelaide in March 1840. He had land in the Hutt Valley, but it seems he preferred being a hotelier to being a farmer. Sources vary as to whether he was Austrian or German, but he most likely lived in London during the 1830s.