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| UTC time | 1888-08-31 16:40 |
|---|---|
| Local date | 1 September 1888 (1888-09) |
| Local time | 04:10 |
| Magnitude | 7.0–7.3[1] |
| Depth | 12 km[1] |
| Epicentre | 42°36′S172°24′E / 42.6°S 172.4°E /-42.6; 172.4[1] |
| Areas affected | South Island New Zealand |
| Casualties | 1 fatality (indirect) |
The1888 North Canterbury earthquake occurred at4:10 am on 1 September following a sequence offoreshocks that started the previous evening, and whoseepicentre was in theNorth Canterbury region of theSouth Island of New Zealand. The epicentre was approximately 35 kilometres (22 mi) west ofHanmer.
InChristchurch, about 100 kilometres (62 mi) southeast of the epicentre, shaking lasted for 40 to 50 seconds. Themagnitude of the earthquake is estimated to be in the range 7.0–7.3. Severe damage to farm buildings in the epicentral region was reported and the top 7.8 metres (26 ft) of the spire ofChristChurch Cathedral collapsed. It was the first earthquake observed to be associated with mainly horizontal fault displacement.[2]
New Zealand lies along the boundary between theAustralian andPacific plates.
In theSouth Island, most of the relative displacement between these plates is taken up along a single dextral (right lateral)strike-slip fault with a majorreverse component, theAlpine Fault.
In theNorth Island, displacement is mainly taken up along theKermadec-Tonga subduction zone, although the remaining dextral strike-slip component is accommodated by theNorth Island Fault System.[3]
The earthquake occurred on theHope Fault, one of the group of dextral strike-slip structures known as theMarlborough fault system that transfer displacement between the mainlytransform andconvergent type plate boundaries in a complex zone at the northern end of South Island.[4]Alexander McKay, a geologist working for the geological survey, observed horizontal offsets in farm fences between 1.5 and 2.6 metres (4.9 and 8.5 ft) along the fault. He was the first to associate a strike-slip displacement with an earthquake.
In the North Canterbury region many buildings were severely damaged, particularly in theHope Valley andHanmer areas.Landslides occurred in unconsolidatedsediment and fissures up to 30 centimetres (12 in) wide were observed.
InChristchurch, the top 7.8 metres (26 ft) of theCathedral spire fell down and minor damage, such as broken chimneys, affected many houses. TheDurham Street Methodist Church, Christchurch's first church build with permanent materials, suffered some damage to its stonework. Another building affected was theChristchurch Normal School, where chimneys fell down and ceilings were cracked.[5]
Damage was greatest in the northern and northwestern suburbs, probably due to thepeaty sub-soil.[5]
One person died of a heart attack during the earthquake.[6]
