Ian Macdonald: Earthquake was a wakeup call for us

Ian Macdonald

Last Friday's early morning earthquake off East Cape is a wakeup call for all of us here in Hawke's Bay.

Around East Cape and Gisborne a number of communities took the initiative and immediately self-evacuated because of the strength and length of the earthquake. They did the right thing.

Evidence from the 2011 Japan Tsunami showed more than 90% of those who left immediately after the quake struck survived. Those who delayed their departure or waited to be told to leave were not so lucky.

In the city of Kamaishi local school students had been practicing self-evacuation after a large earthquake. Immediately after the 2011 earthquake the high school students ran to safe areas. The nearby primary school saw this and did the same along with a number of passers-by. The older students helped the younger children.

The city lost one thousand people to the disaster but only five were school-aged children, and they were not at school that day. These children survived because they knew they were in the danger zone, they knew what to do and they did it immediately.

Do our Hawke's Bay and coastal communities know what to do in a long or strong earthquake? Based on surveys over the last few years only about 20% of our community know what the natural warning signs of a tsunami are and what to do - this is not enough.

People in Samoa, felt a weak long earthquake that lasted longer than a minute in 2009, which resulted in a large tsunami. If last week's earthquake had created a large tsunami like Japan, Hawke's Bay would have felt much stronger shaking. It would have been hard to stand up or walk steadily, and there would be significant household contents damage and building damage.

Based on the speed of the Japanese tsunami, from East Cape it might have arrived along our coast within 20-30 minutes - there are no reliable warning systems that would have been able to issue an official tsunami warning in enough time for people subsequently act and safely evacuate.

Do not wait for an official warning after a long or strong earthquake - evacuate inland or to higher ground immediately.

Think about where you live or where you or your family might be (e.g. work or school) and plan your safe route inland or to higher ground.
Although we haven't experienced significant tsunami along our coastline for a long time, scientific research shows the East Coast has had a large event on average every eight hundred years, but the next one could be tomorrow.

The Hikurangi Trench fault system just off the East Coast and Hawke's Bay has similar characteristics to the subduction zone that created the Japanese tsunami.

Our best defence is individual knowledge and immediate action. You can easily find out if you live or work in a tsunami evacuation area at http://www.hbemergency.govt.nz/hazards/tsunami/evacuation-zones
Remember if you are in one of these zones and feel a weak earthquake lasting over a minute or a strong shake that makes it hard to stand up don't wait - immediately evacuate to higher ground or inland. You cannot afford not to.

■Ian Macdonald is Group Controller of Hawke's Bay Civil Defence Emergency Management Group.