Impact of NZ earthquake felt for years

People living in Christchurch, New Zealand, during the devastating 2011 earthquake experienced ebbs and flows in their physical and mental health in the following years, a new study shows. 

Researchers from Victoria University of Wellington analysed data from official government health surveys conducted from mid-2011 to mid-2016 and found that while initially Cantabrians held up well, many hit a low point in 2013/14 when disillusionment set in.

The researchers say this supports a general theory of how people respond to disasters; an initial heroic honeymoon phase is followed by a down period as it becomes apparent that returning to life as it was before will take some time. But spirits and wellbeing then rise again.

“The results show that both physical and mental health composite scores were greater in the years directly after the earthquake and then decreased, markedly for men, in 2013/14 and have increased since then,” Megan Pledger, Janet McDonald and Jacqueline Cumming write in a paper published in the New Zealand Medical Journal.

“This shape is consistent across age groups for men and in the older age groups for women. For the younger two age groups for women there appears to be a continuing small decline in scores.”

The authors can’t be certain, they say, that this was solely due to the earthquake, but suggest that given the changes it brought to the social and physical environment “it is implausible to think it had no impact”.

The magnitude 6.3 earthquake struck on 22 February 2011. It was an aftershock to a magnitude 7.1 quake that had occurred in the region the previous September, but was more damaging for a number of reasons.

Physically it was closer to Christchurch city (where a number of buildings had been weakened by the previous quake) and it had a shallow epicentre – just five kilometres deep.

And then there was the timing. It struck at lunchtime on a busy working day when people were more likely to be outside in the older and more built-up parts of the city. The September quake had come at 4.35am.

As a result, 185 people died and 164 were seriously injured.

The NZ Ministry of Health ran five surveys over the study period, allowing the researchers to gauge how attitudes and health patterns were changing – and why the up-down-up pattern continues to hold true.

They note, for example, that despite the physical, mental and emotional effort required to live surrounded by collapsed buildings, there was strong community support immediately after the earthquake “with the Student Volunteer Army and the Farmy Army donating their labour and, in the latter case, machinery, as well as longer-term efforts to encourage resilience”.

In contrast, by 2016, 20% of people still had not had their insurance claims settled.

The study also notes the changes to the city’s population, with older people staying but some younger people leaving – mostly into neighbouring districts but also to other parts of New Zealand and overseas.

“As the rebuild started, young males flowed into Christchurch from New Zealand and overseas but there was a continued outflow of young females,” it says.