Southern California's latest earthquakes have shown the value of early warning systems, but it could be a long time before one reaches New Zealand.
The region has faced its two largest earthquakes in 20 years in recent days with the prospect of further aftershocks to come.
But the state has a system that alerts people to quakes of magnitude five or greater.
Victoria University geophysics professor John Townsend told Tim Dower it's a useful system that might work here, as well.
"It's not just California that has this sort of system. They are in active use in Japan and Mexico and Italy, and if the future it would be something ideal to have in New Zealand as well."
However, such a system wouldn't be cheap.
"It includes not just the cost of the seismic infrastructure and all the sensors, but also the autonomous analysis system and the communications systems required to get the message out."