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| UTC time | 1848-10-16 |
|---|---|
| Local date | 16 October 1848 (1848-10-16) |
| Magnitude | Mw7.5 |
| Depth | shallow |
| Epicentre | 41°48′S173°42′E / 41.800°S 173.700°E /-41.800; 173.700 |
| Areas affected | New Zealand,Marlborough,South Island |
| Casualties | 3 deaths |
The1848 Marlborough earthquake was aMw7.5 earthquake that occurred at 1:40 a.m. on 16 October 1848 and whoseepicentre was in theMarlborough region of theSouth Island of New Zealand.[1]
InWellington, the shaking lasted for about two minutes and caused widespread damage, especially to brick or stone structures. Most of the buildings damaged in the earthquake were rebuilt in wood[2] and this contributed to the relatively low level of damage and loss of life in the more powerfulWairarapa earthquake that hit Wellington seven years later.
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 singledextral (right lateral)strike-slip fault with a majorreverse component, theAlpine Fault. In theNorth Island, the displacement is mainly taken up along theKermadec subduction zone, although the remaining dextral strike-slip component of the relative plate motion is accommodated by theNorth Island Fault System (NIFS).[3] A group of dextral strike-slip structures, known as theMarlborough fault system, transfer displacement between the mainlytransform andconvergent type plate boundaries in a complex zone at the northern end of South Island.[4]
The earthquake was associated with therupturing of a minimum of 105 km of theAwatere Fault, which is part of the Marlborough Fault System.[5] A horizontal displacement of about 6 metres was accompanied by smaller vertical movements of varying sense. A shallow epicentral depth is inferred from the large number of feltaftershocks.[6] Amoment magnitude of about 7.5 has been estimated from the rupture length and measured displacements.[5][7]
In Wellington, almost all buildings of brick or stone construction were damaged, including homes, churches, the jail, and the Colonial Hospital.[8] Most wooden buildings were undamaged, although many lost their brick chimneys.[9][10]
Barrack Sergeant James Harris Lovel of the 65th Regiment and two of his young children, Amelia aged 4, and William aged 6, died after being crushed by falling bricks from a wall in Farish Street, Wellington. They are buried at Bolton Street Cemetery.
In the Marlborough region itself, a number of homesteads were badly damaged. Several buildings damaged in the main shock were destroyed during strong aftershocks over the next few days. The only fatalities from the earthquake occurred when a damaged building collapsed during one of the aftershocks the following day.[2]