Opinion: Predicting earthquakes, hopefully a matter of 'when' and not 'if'

Scientists are getting closer to identifying warning signs of events like the 1931 Hawke's Bay earthquake.

No one wants to ever see a repeat of the 1931 Hawke's Bay earthquake.

But it could happen and scientists are slowly getting closer to predicting when.

We sometimes hear scientists say "it's not a question of if, but when" when it comes to the next "big one".

In February 2011, 185 people died after the Christchurch earthquake.

The city had experienced a more powerful 7.1 earthquake in September 2010, but the 2011 quake was shallower, and more destructive.

It is easy to say "hopefully not in my lifetime", but if that is the case, it could still be in our children's lifetime, or our grandchildren's.

In February 1931, 256 people died. There may have been more.

Earlier this month, Hawke's Bay Today wrote about the Jane Doe of the 1931 quake - the woman in her 70s buried in an unmarked grave who has never been identified.

It is also possible that other people died, and the quake's fires erased any trace of them.

There is more than one family in New Zealand who lost contact with a family member around the time of the quake, but that person is not recorded as a victim.

If it ever happens again, there is some comfort in the fact that we may get some warning.
Any post-quake recovery would be far more advanced than what occurred in 1931.

The Hawke's Bay Earthquake - New Zealand's Greatest Natural Disaster by Robert McGregor references a harrowing situation, in which a local doctor chose to euthanise a woman trapped in the remains of a cathedral that had collapsed.

The woman was described as being "imprisoned, and partly buried" in the rubble.

It was a brave decision made in extraordinary circumstances that no person should ever have to endure.

No one could have predicted what happened that day. But one day, we might.

GNS Science's most recent advance has identified signals in the form of a certain type of small earthquake that precludes a "slow slip" event, which some scientists believe signal the stress that occurs within the Earth's crust, that triggers earthquakes.

If GNS advances in identifying preludes to a quake continue, hopefully sufficient warning can one day be given to reduce and even prevent loss of life.

Hopefully it's not a matter of if, but when.