Wood is good in earthquake disaster

Only three per cent of deaths in the 1931 Hawke’s Bay earthquake occurred in wooden buildings, research has found.

A team of epidemiologists, disaster experts, a genealogist and an engineer from Otago, Massey and Auckland universities found that more than half of the 256 deaths were caused by the collapse of just 15 buildings. The 7.8 magnitude earthquake, which struck at 10.47am on February 3 1931, is New Zealand’s deadliest natural disaster.

The researchers concluded that the lack of adequate building regulations in place at the time contributed to the high number of deaths and serious injuries.

Many of the buildings that collapsed were multi-storey constructions made of unreinforced masonry, which were not only a danger to those inside but also killed people in the street.

However, few fatalities occurred in people’s homes, almost all of which were made from wood. The results have been published in the international journal Scientific Reports. Senior author Professor Nick Wilson, from the University of Otago, (Wellington), said there were no building rules at that time that would have been able to reduce earthquake-related risks.

‘‘The picture for this 1931 earthquake had some similarities to the Canterbury earthquake of 2011 in that specific buildings caused most of the deaths and unreinforced masonry fell into streets, killing people there.’’

The value of wooden buildings has repeatedly been shown in earthquakes, as far back as the 1848 Marlborough earthquake, Wilson said.