Unlike Japan, Mexico and now parts of the US, New Zealand doesn’t have a nationally funded earthquake early warning system – something that could cost $25 milliob a year to run here, and perhaps $50m to prepare. Photo / J Thomson, GNS Science
It’s touted as wonder tech that gives people a few potentially life-saving seconds to prepare before a major earthquake hits.
These platforms operate by detecting and reacting to an earthquake’s fastest-travelling “P-waves” before the slower but more damaging “S-waves” arrive, enabling users precious moments to drop, cover and hold.
New Zealand is one of few countries to host a Google system that pings messages to people’s Android phones before a quake’s shaking, telling them its estimated strength and how far it is from them.
Kiwi company Jenlogix also operates a network of P-wave-detecting Palert units that is used by several councils, universities, district health boards, ports, and power companies, while Massey University researchers have been exploring other low-cost sensors, like the Raspberry Shake plug-and-play seismic stations.
But unlike Japan, Mexico and now parts of the US, New Zealand doesn’t have a nationally funded EEW system – something that could cost $25 million a year to run here, and perhaps $50m to prepare.
A 2013 GNS Science report found creating one would require a massive upgrade to our geodetic sensor network, along with a “significant increase” in funding.
Now, survey data just published by Massey researchers suggests New Zealand has also got a long way to go before we’d use one properly.
“We know from previous research when that people in New Zealand think earthquake early warning might be useful, and that they think they’ll react well to receiving a warning by protecting themselves,” said study author, Dr Lauren Vinnell, of Massey’s Joint Centre for Disaster Research.
“The launch of the Android Earthquake Alert system allowed us to test how Kiwis actually respond to a real alert.”
In a global context, New Zealand’s response to it was particularly informative, as its introduction had come with scant communication and education about it.
“This meant we could explore how people respond to a new system that they don’t know about.”
As they expected, public awareness about it proved low, with around 70 per cent of the 3000 participants in the survey reporting they knew nothing or little.
“Although over 80 per cent of people said they found the alert useful or somewhat useful, only about 5 per cent used the time they got from the warning to take protective actions before the shaking started,” Vinnell said.
“Instead, they mostly waited to see if an earthquake was actually going to arrive, looked to confirm the alert, or told people around them.”
While those reactions might make sense for something people hadn’t seen before, she said, it wasn’t helpful for keeping people safe.
“Also of concern is that only a quarter to a third of participants knew that the alert came from Google, with many others thinking it came from Nema, GNS, or GeoNet.”
Earlier survey work by the group turned up more general issues with Kiwis’ readiness for EEW systems – namely that doing exercises or drills didn’t seem to prompt the right actions for warnings, such as drop, cover, and hold.
There were several possible reasons for that: one being a lack of education in linking warnings with drills like the annual ShakeOut, which has been shown to boost people’s use of protective actions in actual quakes.
Rather, the researchers found the more personally relevant a person’s experiences were – like having a family member previously injured from a quake – the more likely they were to intend to take a useful action when they got an alert from an EEW system.
Those whose loved ones had been hurt were more likely to move somewhere safe, mentally prepare, tell others, or pull over and stop if they were driving.
Regional experiences with bigger quakes also seemed to play a part: people in Canterbury and Wellington reported a greater likelihood to mentally prepare for a quake if they got an early warning.
While having an EEW system was seen as more useful among people whose family or friends had been affected, this effect was statistically small – and there were no observed differences for other types of experience, including among those who’d been hurt themselves.
“It’s really important that people know what to do to protect themselves during earthquake shaking so that they can act whether they receive a warning or not,” Vinnell said.
“We don’t want people to become reliant on these warnings because they might not get one for strong earthquakes that could cause harm.”
If New Zealand ever did launch its own state-run EEW system like Japan’s, Vinnell said it would be crucial to first educate the public about how they should be used, and what their limitations were.
“It’s important that people understand who is responsible for EEW systems, as mistakes from the system which aren’t properly explained could lead to loss of trust, so as our findings suggest people might lose trust in our official agencies who are not the ones delivering this service.”
Jamie Morton is a specialist in science and environmental reporting. He joined the Herald in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.