Editorial: Speed a key to survival

We have 40mins to get away if a tsunami was to hit Papamoa and Mt Maunganui.

At last we have a clear picture of the possible impact a tsunami would have if it hit our coastline.

Miserable and wet but alive is the latest prediction of what will happen if people react quickly to the threat of a worst-case tsunami hitting Papamoa and Mount Maunganui.

Data based on a massive magnitude 9 earthquake along the Kermadec Trench running north-east from the Bay of Plenty is being translated into an evacuation map for Tauranga's vulnerable low-lying suburbs.

And while details of the map were still being refined, the council's emergency management spokesman Paul Baunton says it shows people could survive a 14m tsunami - provided they responded quickly to the warning signs.

Interestingly, he stresses that if people rely on authorities telling them when to evacuate, the tsunami will have arrived.

The lesson from the Japan tsunami was that everyone should be self-reliant.

This fits with the view of Dr Graham Leonard, a natural hazard scientist at GNS Science, who says sirens and other official warning mechanisms can have major deficiencies.

This is because it is difficult to activate them reliably and quickly because of the lack of data within the first tens of minutes during and after an earthquake, he says.

After the 2011 deadly Tohoku tsunami in northern Japan, New Zealand scientists visited seven of the hardest-hit coastal communities in Japan.

In the north of Japan, where community drills are conducted to evacuate immediately based on an earthquake alone, groups recorded fewer fatalities or none at all.

Elsewhere in places where some people appear to have been waiting for whatever reason - such as for official warnings - there was often a lower survival rate.

Based on these findings, I'm sure many coastal residents will study the map when it is released and plot their evacuation route.

Self reliance and preparedness appear to be keys to survival should such a disaster occur.