M 7.8, Marlborough, October 16 1848

The earthquake that shook Marlborough on Monday, October 16 1848 was the largest in a series of earthquakes to hit the region that year.

[Park, Robert] 1812-1870. Attributed works: Sketches showing the damage to buildings sustained in the 1848 Wellington earthquake.

Reference No. PUBL-0050-01
Part of : An account of the earthquakes in New Zealand. Extracted from the New South Wales sporting and literary magazine and racing calendar. (Sydney, Printed by D. Wall, 1848) (PUBL-0050)

Permission of the Alexander Turnbull Library, Wellington, New Zealand, must be obtained before any re-use of this image

• Location: Marlborough
• Date (NZ Local Time): Monday, October 16 1848 at 2:05 am
  
• Epicentre: 41.8°S, 173.7°E
• Focal Depth: 20 km
• Maximum Intensity: MM 10
• Magnitude: M_W 7.8

Once attributed to movement on the South Island’s Wairau Fault, the earthquake is now thought to have been the result of movement on the nearby Awatere Fault. The main shock was felt most severely in the Wairau Valley and in Cloudy Bay, where the shaking demolished houses and fissures broke the ground. Wellington and Nelson also suffered significant damage to structures and buildings from these earthquakes.

The main shock was felt strongly as far away as the East Cape, northern Taranaki and Banks Peninsula but, like the other quakes in the swarm, it was experienced most severely in the centre of the country. The lower Wairau Valley bore the brunt of its force, experiencing intensities of MM 10, while intensities of MM 9 destroyed a number of cob houses in both the Waihopai and lower Awatere Valleys. The earthquake also greatly disturbed the surrounding landscape, triggering numerous landslides in the hills and rupturing the ground over a distance of more than 105 km along the Awatere Fault itself.

In Wellington the severity of the shaking (MM 8) caused extensive damage, while in Nelson, Wanganui and Manawatu the intensities reached MM 7. The earthquake triggered landslides along the south-east coast of the Wairarapa and in the Rimutaka ranges. Most of the houses in the Wairarapa suffered chimney damage, and at least one was shifted from its piles by the ground movement. The occurrence of landslides and groundwater ejection were unusually widespread in this earthquake; it is possible that this was due to the period of extremely wet and stormy weather that preceded the quake.

The earthquake was followed by a long series of aftershocks. The largest struck two days after the principal shock, at 4 o’clock in the afternoon on Tuesday, October 17 (New Zealand Local Time), and killed three people. Although the shock was smaller than its predecessor, with a magnitude M_L 6.1, it caused significant damage because a number of structures had been left severely weakened by the October 15 earthquake.