1942 Wairarapa earthquakes
|Local date||24 June 1942|
2 August 1942
|Areas affected||New Zealand, North Island|
Two 1942 Wairarapa earthquakes shook the lower North Island of New Zealand; on 24 June and 2 August. They were large and shallow with the epicentres close together east of Masterton in the Wairarapa region. The June earthquake was sometimes referred to as the Masterton earthquake but both caused damage over a wide area, from Dannevirke, and Eketahuna to Wellington Whanganui and Otaki. There was one death in Wellington, on 24 June. 
The August earthquake can be regarded as an aftershock of the June earthquake. Both earthquakes were preceded by smaller foreshocks. As the second quake was slightly less in magnitude than the first, they were not an earthquake doublet where the second shake is slightly larger . The August earthquake was considerably deeper (40 km, not 12 km), though another source gives the depths as 43 km and 15 km. There was a further large aftershock on 2 December and another in February 1943.
The Wairarapa Region
24 June 1942
At 11.16 pm a small and sharp but brief earthquake of magnitude 7.2 Ms (Mw 6.9-7.2) shook a wide area in the lower North Island from Eketahuna to Masterton, Featherston and Wellington; and was noticed from Auckland to near Dunedin. The main earthquake was of 7.2 Ms and the epicentre was near Masterton and 12 km deep. The quake lasted for over a minute and had been preceded by a foreshock three hours earlier at 8.15 pm.
In Wellington twenty thousand chimneys fell, and there was one death in the suburb of Kelburn when a 70-year old retired chemist Hedley Victor Evens (sic) was killed by coal gas from a fractured pipe. Some downtown pediments were damaged, but some had already been removed after the 1931 Hawke's Bay earthquake. The city engineer K. E .Luke held that damage was less severe as the quake ended swiftly. 
2 August 1942
Another shock in the area struck on 2nd August at 12.34 am, preceded by a foreshock on the late afternoon of the 1st. This was of magnitude 7.0 Ms (Mw 6.8) or slightly less than the earlier quake. The epicentre was 40 km deep and at location 41.01°S and 175.52°E.
Wairarapa except for Eketahuna  did not suffer as badly, though in Masterton the June damage was exacerbated.  The 2 August aftershock was followed by a third severe aftershock on 2 December, with about 600 aftershocks recorded to the end of the year. 
Repairs from the first quake were not completed, and the mortar for some repairs had not properly set. Some buildings weakened in June suffered further damage, though it was sometimes hard to tell if further damage had occurred. 
In Masterton many buildings were badly damaged by the first quake; the fire station, the Bank of New Zealand, several shops and St Matthews Church (which was later blown up by the Army). The Waiohine road bridge was badly sunken and was closed. After the second quake the Wairarapa Farmers Co-op building partly collapsed.
In Wellington the first quake toppled some twenty thousand chimneys. In August there was serious damage in the Willis Street – Manners Street area to three buildings: Charles Begg's music shop, the Duke of Edinburgh Hotel, and the Regent Hotel.    Manners Street between Willis and Cuba Streets was closed for several months.  
Overall cost and effect
The cost of the damage from these two quakes was more than £2 million (pounds), a considerable amount for a war-straitened economy. In Masterton damage from the two quakes was still apparent some 12 years later. 
- Wright 2014, pp. 139-142.
- Rogers 2013, pp. 132-141.
- Hicks & Campbell 1998, p. 70.
- Wright 2014, p. 141.
- Rogers 2013, p. 132.
- Rogers 2013, pp. 136-139.
- "An earthquake caused mayhem and there was a lucky escape". Stuff (Fairfax). 10 March 2018.
- "Kelburn Tragedy". Evening Post in Papers Past. 29 June 1942.
- Wright 2014, p. 140.
- Wright 2014, p. 139.
- "Huge fissures near Eketahuna (photo)". Evening Post in Papers Past. 29 August 1942.
- "Queen Street shop in Masterton destroyed (photo)". Evening Post in Papers Past. 26 June 1942.
- Rogers 2013, p. 140.
- Rogers 2013, p. 141.
- "Queen Street and Waiohine Bridge (photo)". New Zealand Herald in Papers Past. 27 June 1942.
- Rogers 2013, p. 140, 141.
- "Destruction in Wellington Province (photo)". Otago Daily Times in Papers Past. 29 June 1942.
- "Damage to businesses (photo)". New Zealand Herald in Papers Past. 27 June 1942.
- "Charles Begg split". Papers Past (photo). 3 August 1942.
- "Propped-up scaffolding". Evening Post in Papers Past (photo). 5 August 1942.
- "Manners Street scaffolding". New Zealand Herald in Papers Past (photo). 8 August 1942. Missing or empty
- "Looking along Manners Street". Evening Post in Papers Past (photo). 12 August 1942. Missing or empty
- "Top of Regent Hotel split". Evening Post in Papers Past (photo). 3 August 1942.
- "Scaffolding in Manners Street (photo)". Evening Post in Papers Past. 8 August 1942.
- "Damage to Wairarapa Farmers Co-op Masterton (photo)". New Zealand Herald in Papers Past. 26 June 1942.
- Rogers 2013, pp. 140,141.
- Rogers, Anna (2013) . The Shaky Isles: New Zealand Earthquakes (2 ed.). Wellington: Grantham House. ISBN 978-1-86934-119-0.
- Wright, Matthew (2014). Living on shaky ground: The science and story behind New Zealand's earthquakes. Auckland: Random House (New Zealand). ISBN 978-1-77553-688-8.
- Hicks, Geoff; Campbell, Hamish (1998). Awesome Forces: The Natural Hazards that threaten New Zealand. Wellington: Te Papa Press. ISBN 978-0-909010-58-4.