Last night’s series of earthquakes in Southland created fierce debate on our Facebook page between some New Zealanders, with an almost competitive streak coming out as a few in Christchurch dismissed the quakes as news, while others fired back saying earthquakes can happen anywhere in New Zealand and all moderate to big quakes are newsworthy.

It was the first time that WeatherWatch.co.nz administrators had to ban and delete comments as arguments became personal.  Around 90 comments were posted within an hour, several were deleted.

A similar series of arguments occurred  last year when parts of Auckland were jolted by an extremely rare, small, but noticeable earthquake – prompting Philip Duncan to write this blog titled Why Auckland’s Quake Even Made The News

And today GeoNet’s Outreach Coordinator, Sara Page, has written a new blog titled “Earthquakes – a competitive sport?” following the comments we received last night.  We thank Sara for sharing this with WeatherWatch.co.nz readers.

Earthquakes – a competitive sport?” – by Sara Page 

New Zealanders are well know for their competitive nature when it comes to sport, which is great as we are pretty good at it! But it has come of a bit of a surprise lately at the ‘mine was bigger than yours’ mentality people seem to be getting regarding earthquakes.

I’m sure most people remember the small earthquake in Auckland last year, yes everyone had a bit of a laugh and there were plenty of ‘oh no my latte has fallen over’ jokes! But in all seriousness Auckland does not get a large amount of felt earthquakes, and living on top of over 50 volcanoes we should let them worry a bit when they do feel shaking – as this is often a precursor to eruptive activity!

Fence crossing the Hope Fault – it was straight until 1888!

Back to the rest of NZ – at GeoNet we record over 15000 earthquakes every year – luckily most are not felt! We do however, get a few ‘biggies’ every now and then, here is a wee jaunt through our earthquake history::

North Canterbury 1888 ~ 7.1
This earthquake had a shaking intensity of MM9, it occurred on September 1st 1888. As you can see in the picture on the right – it created a fair amount of land movement, there were also numerous landslides, liquefaction and broken chimneys.

Wairarapa 1855 ~ 8.2
With a maximum intensity of MM10 this earthquake was felt all over NZ, around 7-9 people were killed and 5 injured. This is also the famous event that uplifted many areas in Wellington including: the Basin Reserve (sports ground) which used to be under water, as well as the harbor ( Lampton quay used to be the waterline), and even the land our airport is on.

Fault Scarp in Buller Gorge.

Buller/Murchison 1929 ~ 7.8
On June 17 this large event occurred, luckily in an area sparsely populated, though it still killed 15 people and injured 1. The quake had an max intensity of MM10 and was felt all over NZ, and damaged many roads, bridges and buildings. The quake also created 38 new lakes after slips blocked rivers (21 still exist today). If you look at the picture on the left, the wee man on the bike is on the other side of the road, now 4m higher than the rest!

Severely damaged road – Hawkes Bay

Hawke’s Bay 1931 ~ 7.8
This earthquake caused the largest loss of life and most damage of any quake in NZ history (prior to the Canterbury events) The MM10 event killed 256 people and injured thousands, the earthquake was followed by devastating fires that were unable to be stopped as the water mains were broken. This event also changed the coastline and deformed much land in the area.

Rift in a paddock – Edgecumbe.

Edgecumbe 1987 ~ 6.5
This event is well remembered in NZ history, it occurred on March 2nd and had a max shaking intensity of MM9. 25 people were injured, and although many buildings collapsed – fortunately they had been evacuated following a large foreshock.

Dusky Sound 2009 ~ 7.8
This event is the largest in New Zealand since Marlborough 1848 and Buller 1929. With a max. of MM7 it triggered numerous landslides and even a small tsunami.

And of course we have the 2011 Christchurch ~6.3 earthquake, with MM9, 181 people killed and 164 seriously injured. For more info on the canterbury events, see our pages here

Although the size of these earthquakes vary, it is interesting to see how the maximum shaking intensity(MMI) is pretty similar. Looking at the maximum shaking intensity is a much better indicator of how earthquakes effect people and the environment, rather than just the magnitude. You can read more on the MMI scale here

Now this is just a few of the major historic earthquakes in NZ, for more info on these events and others go to our ‘historic quakes’ page here

And back to my original point(s)
*All of New Zealand gets earthquakes, both small and damaging. So stick together – offer help and words of support, rather than tell people to ‘get over it’ as it was ‘only a baby one’. We are only a small country, stick together!
* and remember to look at the MM shaking intensity of an earthquake before you judge on its size, it may have been small but strongly/widely felt!

 – Sara Page, GeoNet – click here to read her other blogs