It is June 1929. The world is on the precipice, but nobody seems aware of it. A French monoplane has successfully flown across the Atlantic from Maine, USA to Santander, Spain. The British withhold resumption of diplomatic relations with the Soviets to confer with the US 1/n

In Asia there is ongoing fishing disputes over the waters off Kamchatka between the Japanese & Soviets, the threat of renewed conflict looming. In the UK the new US ambassador has arrived in Southampton via the liner Olympic & had an audience with King George V at Windsor 2/n

The issue of US tariffs on Canadian goods is causing problems in Ottawa, with the Liberal government declaring free trade within the British Empire is the answer. Clashes erupt in Apia, Samoa, between members of the Mau movement & New Zealand police, injuring 18 3/n

In Nicaragua the US government secures permission for a battalion of engineers to survey for a new canal through the country to rival the Panama Canal. In Morocco, the French continue to subdue a revolt by artillery & aerial bombardment of the town of Yakoub 4/n

In South Africa the result of the general election keeps General Hertzog in power; with the support of the Labour Party, his Nationalists have a majority of 26 over the South African Party. A by-election in Rugby, UK, results in the status quo; a Conservative hold of the seat 5/n

In New Zealand, winter has set in. Temperatures in Auckland are 13⁰C over the weekend of the 15th & 16th, whilst in Christchurch they were 2⁰C. The weather is general cloudy, with winds from the south-west. Rain is forecast in the next few days 6/n

New Zealand’s year has already been eventful for earthquakes. Late in the evening of March 9th a powerful Mw 7.0 quake ruptures the Poulter Fault near Arthur’s Pass, resulting in power cuts there until the next mornin & all chimneys there & in Otira collapsing 7/n

This Arthur’s Pass quake was the largest to strike New Zealand since November 1914 & the largest shallow quake since the August 1904 Cape Turnagain Earthquake. It was felt from Auckland down to Invercargill, but only strongly from Wellington down to Oamaru 8/n

Not two months later, in the early hours of May 8th a moderate, shallow Mw 5.5 quake strikes the Rangitikei near Marton. This quake causes widespread cracking of chimneys, falling of chimney pots & breakage of fragile items in the towns of Marton, Feilding & Hunterville 9/n

By the middle of June, 1929 has already been an unusually active year for seismicity in New Zealand. That was all about to change, at 10:19 New Zealand Mean Time, on a cold June Monday morning. It was the 17th June 1929, & the quake was the Mw 7.7 Buller Earthquake 10/n

The earthquake struck on a ~64km long subsurface reverse fault, with surface faulting occurring on an 8km length of the White Creek Fault near Inangahua. The quake is estimated to have had a centroid depth of 9km, a remarkably shallow quake & incredibly dangerous 11/n

The surface faulting shows vertical displacement of 4.5m, and sinistral strike-slip motion of 2.5m. This compares with a 16-36km long surface rupture for the Arthur’s Pass quake with maximum surface faulting of 4m of dextral slip and 1-2m of dip-slip motion 12/n

The earthquake struck a relatively uninhabited region which is incredibly difficult to access, with thick woods and generally mountainous country. Landslides were extensive – the most extensive since the 1855 Wairarapa Earthquake – affecting ~7,000 square km of land 13/n

These landslides proved the biggest hazard to human life. Sixteen people were killed by the Buller quake, 14 in landslides - some of which simply wipe away homesteads - & 2 more due to rock falls in nearby coal mines. At the time it is the deadliest New Zealand earthquake 14/n

Newspaper articles from Monday 17th June & Tuesday 18th June give a great impression of the extent of the impact of the Buller Earthquake. I chose four towns/cities – Hokitika on the West Coast, Nelson & Christchurch on the South Island, & the capital city of Wellington 15/n

Hokitika suffers a reasonable level of damage considering it is over 100km away from the causative fault. People ran out of buildings, articles crashed & fell from shelves in buildings, and most chimneys crashed down onto streets & properties 16/n

It is a similar story along the other towns of the West Coast. At Greymouth hundreds of chimneys fall, frontages of shops are destroyed, and a big slip occurs at Cobden quarry. Chimneys fall also at Reefton & the contents of shelves at the hotels smashed wholesale 17/n

The reports from Reefton reveal that there were foreshocks to the 10:19 a.m. Mw 7.7 mainshock. These were felt at 00:45 (intensity MM IV or higher) and also at 07:20. This is also known from more epicentral locations, with numerous small foreshocks during the morning 18/n

In Nelson the quake causes people to run out into the streets, the ground shaking so much keeping balance is a challenge. Masonry & chimneys fell throughout the town, and several buildings including the Boys’ College rendered unsafe for occupation 19/n

Christchurch had a better time of it, owing to it’s greater distance from the quake than Nelson or Hokitika. A few chimneys fell in suburbs, windows were cracked, & small pieces of masonry & mortar fell from many buildings, but damage was slight compared to further north 20/n

In Wellington the quake was so strong that the seismological instruments at the Dominion Observatory were thrown out of operation. Many ran into the streets, some windows were broken, & a few objects fell from shelves, but otherwise Wellington emerged relatively unscathed 21/n

Damage was reportedly far more severe in Westport, but owing to magnitude of the quake telegraph wires were severed & only restored a few days after the quake. Almost all buildings collapsed or partially collapsed, fronts of buildings collapsing & all chimneys falling 22/n

There were lucky escapes in Westport, where amazingly nobody died. One girl reportedly lost her foot, a woman had both legs broken, and a teacher & pupil were buried beneath a huge piece of concrete & were freed almost unscathed, with just a few bruises 23/n

The railway lines were twisted by the earthquake – a familiar sight with shallow quakes in New Zealand today, after Darfield in 2010 & Kaikoura in 2016 – and the wharf at Westport was badly warped. The Post Office was effectively reduced to a mound of brick & mortar rubble 24/n

Damage was also severe further north around Takaka & Collingwood. Much of this sparsely populated part of the South Island remained cut off by landslides, disease & hunger becoming realities in completely cut-off communities such as Karamea, which was only accessible by sea 25/n

The Buller Earthquake is not forgotten, but has been overshadowed by the disastrous Mw 7.8 1931 Hawke’s Bay Earthquake 20 months later, which killed 261 people destroyed Napier & much of Hastings. The Mw 7.1 1968 Inangahua Earthquake is also more recent & in living memory 26/n

Aftershocks to continued throughout 1929, with numerous ~M6 quakes striking during the next 2 months, causing further minor damage & hampering relief efforts. New Zealanders rallied around those affected, raising hundreds of thousands of pounds in relief funds 27/n

This quake, and the March 1929 Arthur’s Pass quake, marks the beginning of what is regarded by many as a decade-long period of increased seismicity in New Zealand, it being followed by 1931 Hawke’s Bay, 1932 Wairoa & 1934 Horoeka (formerly Pahiatua) 28/n

Whether these quakes were in any way linked we’ll never know (spoiler: most likely not!), but this cluster has become more popularly known due to the recent apparent cluster from 2009 Dusky Sound through to 2016 Kaikoura 29/n

In recent years seismicity in the Buller region has been very quiet. The last notable quakes in the region were the January 1991 Hawks Crag Earthquakes which damaged chimneys & buildings’ contents in Westport. 1929 should not be forgotten though 30/n

The earlier 1868 Cape Farewell quake was of a similar magnitude to 1929 Buller, and caused widespread damage. These quakes may not occur all too often, but the hazard is there, and population & infrastructure have drastically increased in the meantime 31/n

The 1968 Inangahua Earthquake killed 3 people and injured 14. The next large Buller quake – it’s not a case of if it will strike, but when – may not be as forgiving as Inangahua. Lessons must be learnt from quakes like 1929, & the quakes themselves remembered for the future 32/32