Source: National Emergency Management Agency (NEMA)
NEMA’s Director Civil Defence Emergency Management John Price says the systems that issued and transmitted the alerts worked well on the day – and that public safety was at the centre of the decision to issue alerts. He says NEMA has now identified why some people received multiple alerts, or no alerts at all.
John Price says these issues are largely down to how different mobile devices behave, and the decision to send the alerts only to cellphones in coastal locations.
“First of all, we know explanations are little consolation for those who were awoken by alerts in the middle of the night. We are very sorry that this happened, and we’re looking at ways to address this in future. However, we make no apologies for getting the message out to keep people safe.
“NEMA only issued two alerts – at 4.13pm on 30 July and 6.30am on 31 July – but some people received multiple alerts during the night. We’ve discovered this is likely related to overnight software updates and device settings.
“As for those who didn’t receive alerts – tsunami alerts are only sent to coastal areas, so if you were inland then we didn’t send you the message because you were not at risk.
“The good news is that there is no problem with the systems we use to send the messages. The alerts were effective in reaching the targeted coastal areas and getting the message out to stay away of the water while dangerous tsunami activity was happening.
“We sent alerts to over three million mobile devices around the country, and when you consider the sheer variety of makes, models, and software, it’s inevitable some variations will emerge at the receiver end.
“After every emergency, we debrief to identify what went well and what needs to improve. We’re working through this now to ensure we’re doing the best we can at keeping people safe from tsunami and other threats.”
John Price says over 30 countries have cell broadcast alerting systems similar to New Zealand’s, and they have proven effective in alerting the public to severe and urgent threats to life, health or property.
“Emergency Mobile Alerts reach nine in ten people, so is a really reliable and effective way to get the message out so people know what to do to stay safe.”
Q&A
Why did I get multiple alerts?
Firstly – we are very sorry to everyone who found this disruptive, especially those who got woken several times in the middle of the night. This was not the intention and there are a few possible explanations.
- When your phone does an automatic software update overnight it reboots. If you turn your phone off and on again during an alert broadcast, you will get the alert again. So when your phone reboots after an update, you will get the alert a second time.
- During the early morning hours, some devices refresh their network connections. This process may have cleared cached data, prompting your phone to give you the alert again. While your device should recognise that it has already received and displayed the alert, it appears that some devices are more conservative and elect to redisplay.
- If you have multiple active Sims / eSims, you will get an alert for each Sim.
- If your phone moved between 3G and 4G networks during the alert broadcast, you will get the alert again each time your phone connects to the new network. This can happen if you’re travelling into a poor coverage area, or if your phone drops in and out of networks.
- Some phones have an optional alert reminder feature turned on. This can cause your phone to alarm repeatedly during the alert broadcast. If your phone does have this feature, you should be able to find it in your phone settings and turn it off.
As we don’t have any control over how individual devices behave, we can’t completely stop these issues from happening again – but we are looking at ways we can reduce their impact.
Why did I get the alert at a different time?
We issued the alerts at 4.13pm on 30 July – to warn that the dangerous tsunami activity would hit overnight – and on 6.30am the following morning – to warn that the activity was now hitting our shores. But we continued to transmit these alert broadcasts for several hours. This was so people entering the area later still got them.
You might have got an alert when commuting home at 5.30pm, or into work at 8am.
The most likely answer is that you were outside the coastal areas we sent the alert to. But then you entered the broadcast zone at a later time, triggering the alert on your phone.
So – if you took the 7am train from Upper Hutt to Wellington, you’d probably have received the alert around 7.20am as you entered Lower Hutt and into the coverage of the cell towers closer to the coast. Your fellow passengers may have received them at different times, depending on the location of their provider’s cell towers.
Or if your phone was off or in flight mode at the time the alert was sent, you would get the alert once your phone turned on or out of flight mode.
Why didn’t I get an alert?
Do you live in Hamilton? Palmerston North? Geraldine? Or perhaps an inland suburb of a coastal city? Then don’t worry – we never sent it to you.
Emergency Mobile Alerts are sent to zones that are geotargeted based on where the risk from the hazard is. We identify the cell towers from all three telecommunications companies in the hazard area, draw a shape around them, and send the message to the area inside that shape.
Tsunami only impact coastal areas, so we issue alerts to geotargeted locations that are forecast to be impacted by the tsunami waves. For the Kamchatka event, we issued alerts to all coastal parts of New Zealand – but not to inland communities.
Not inland? Check out our troubleshooting advice on why you might not have got an alert.
It’s important to remember that Emergency Mobile Alert is an extra channel to help keep you safe in an emergency. It does not replace other alerting systems or the need to take action after experiencing natural warning signs. Seek information from radio and other media, your local Civil Defence’s online channels, and trust your own danger sense if you experience natural warning signs such as a long or strong earthquake by the coast, or rising floodwaters.
Why did everyone in my house get the alert except me?
We get asked this a lot, and on the surface it must seem like something’s gone wrong. Usually there’s a straightforward explanation – you’re on the border of the geotargeted broadcast area.
The geotargeted areas aren’t a clean border. It dep
