Kiwi earthquake expert says cost of Chinese concept probably too high but tsunami network justified.
One of the world's leading earthquake scientists has called on New Zealand to adopt cutting-edge technology that could give people as much as 25 seconds' warning before a big quake strikes.
Dr Tun Wang told the Herald that New Zealand needed the early warning system he had established in Western China in the wake of the Sichuan Earthquake in 2008, which left 70,000 people dead.
Had his system been in place when that earthquake happened, he estimated as many as 30,000 people might have lived had they been given a few seconds of warning.
Dr Wang was working in Austria when the earthquake shook much of his home province to ruins, and returned to establish such a system under his Chengdu-based Institute of Care-life.
Japan and Mexico were the only other countries with early warning systems, with North America and Indonesia recently moving to install them, he said.
"Even though the quality of buildings is good, New Zealand still needs an early warning system."
Dr Ken Gledhill of GNS Science, the crown institute responsible for monitoring earthquakes, was aware of Dr Wang's system and said such a concept had been considered here.
However, its potential cost and practicality meant there were higher priorities.
New Zealand geology meant earthquakes could happen anywhere in the country, so an extensive network of sensors numbering in the thousands would be needed to capture an area of about 270,000sq km.
"The potential costs are pretty high, so if you're going to do it well, you've actually got to line it up against all of the other things the country wants to do," Dr Gledhill said.
"If we went to the Government and asked to spend literally millions and millions of dollars on an early warning system, I doubt it would go very far."
Alongside such a vast network, the country would require the capacity to move the required data around, something which could be possible after the roll-out of ultrafast broadband.
In the South Island, a logical threat for a warning system was the Alpine Fault.
The huge fault is expected to rupture within 50 years, producing a one-in-500 year event that will produce a devastating earthquake of a magnitude 8 or more.
Its impact on Christchurch would be similar to the force of the September 4 2010 quake, yet it would be West Coast townships that would suffer most of the casualties.
Dr Gledhill said a warning system designed for tsunami, as in Japan, could be needed more than an earthquake-focused network.
"The Japanese system is pretty impressive and has been going for quite a few years, and it's probably more along the lines of what we'd have to do in New Zealand, although the population density is obviously quite different."
Beating the quakes
* Dr Tun Wang's network features thousands of monitoring stations, roughly 15km apart, and spread across 10 provinces and over 540,000sq km.
* Sensors could pick up large imminent earthquakes as early as 25 seconds before they happened, instantly sending messages to cellphones, computers and televisions.