Editorial: Earthquake aftermath sparks fresh debate on tsunami sirens

Councillor Steve Morris has put a notice of motion that the council considers the use of sirens. PHOTO/FILE

The devastating earthquake near Kaikoura has reignited discussion about whether tsunami sirens should be in place along our coastline.

The question over the effectiveness of sirens as an alert mechanism has been the subject of much hand-wringing for the Tauranga City Council - and it looks like it will have to consider the issue again after a notice of motion put forward city councillors Steve Morris, Bill Grainger and Leanne Brown.

Three years ago, Tauranga City Council placed a controversial tsunami project on the backburner to focus instead on evacuation routes. The reasons for doing so appear sound.

Commenting on the topic in 2014, Dr Graham Leonard, a natural disaster scientist at GNS Science, said studies had found sirens and other official warning mechanisms could have major deficiencies when it came to local tsunami from earthquakes, including difficulty in activating them reliably and quickly because of the lack of data within the first 10 minutes during and after an earthquake.

Ministry of Civil Defence and Emergency Management guidelines recommend that communities be educated to have an emergency plan and recognise and respond to the natural warning signs for local tsunami.

People are advised to head to high ground or inland if a quake is so strong that it is difficult to stand up or if it lasts more than a minute.

New Zealand scientists visited seven of the hardest-hit coastal communities in Japan after the deadly Tohoku tsunami.

In the north of Japan, where community drills were conducted to evacuate immediately based on an earthquakes alone, groups recorded fewer fatalities or none at all. Elsewhere in places where some people appeared to have been waiting for whatever reason - such as official warnings - there was a lower survival rate.

Warning sirens were found to be problematic in the Tohoko event. Some sirens failed to work. Others sounded on cue, but because there had been numerous false alarms in the past, many people ignored them.

Many people felt the effectiveness of the alert systems following Monday's quake was ineffective. Many slept through the text alerts and were unaware of the email notifications. The sound of a text message arriving would fail to wake most sound sleepers.

An online petition has been launched calling for sirens to be installed and so far thousands of people have put their names to it. Almost all of those who responded to an unofficial poll of 60 people by the Bay of Plenty Times felt sirens should be in place.

Whatever the view of scientists, residents clearly feel safer if sirens were in place along the coastline to sound an alarm and authorities need to take heed of this.

Perhaps though, the most alarming observation to arise from the aftermath of Monday night's devastating quake is the sense of confusion felt by those who were aware of the alerts and took steps to get to safety.

This was highlighted by the case 84-year-old Sheila McLean who evacuated on her mobility scooter after receiving a call from her daughter. She headed to the evacuation point at Baypark but found no one there. She was rescued by a stranger who found her riding the scooter along State Highway 29A towards Maungatapu.

She was concerned by the complacency in the community and the possibility that many were unaware of the alerts that had been issued.

A spokesman said Civil Defence would not be able to have people at safe assembly areas and people were asked to be self-reliant for the first few hours. Of course, resources would be stretched in the event of a natural disaster but I would have thought having someone official at safe assembly points would be a good idea, if only to provide some comfort to people who have fled there homes.

Much can be learned from the events of Monday night but if there had been a clear and present threat then our collective preparedness was found wanting. Authorities do not bear the full responsibility for this but clearly they have some work to do to raise awareness about evacuation routes.

Efforts need to be made to raise public awareness of the advice to head to high ground or inland if a quake is so strong that it is difficult to stand up or if it lasts more than a minute.

This, rather than the installation of sirens, is the most pressing concern.