US scientists have developed an app that allows smartphones to double as earthquake early warning systems.

But New Zealand earthquake experts have cast doubt on the ultimate usefulness of the innovation.

The MyShake app for Android phones was created by the University of California at Berkeley and Telekom Innovation Laboratories in Silicon Valley.

It uses the smartphone’s inbuilt accelerometer to detect the size of a tremor, then sends the data and the phone’s location to Berkeley’s seismological lab.

The aim is to create a worldwide seismic-detection network that can warn users of impending tremors from nearby quakes.

The app uses little power and can detect quakes above magnitude five within 10km.

Telekom says the app could aid countries that have limited ground-based seismic networks.

“Especially for many earthquake-prone developing countries such a Nepal or Peru, MyShake could warn potentially affected persons valuable seconds earlier and, ideally, save lives.

“And what these accelerometers lack in sensitivity, they make up for in their omnipresence. There are an estimated 16 million smartphones in California, and 1 billion smartphones worldwide.”

But John Callan, Communications Manager with quake monitor GNS Science in New Zealand, told insuranceNEWS.com.au the MyShake technology may not be mature enough to be useful in New Zealand.

“From our point of view, the most likely application, and one that is already in use in Japan, is to provide a few seconds’ advance warning of severe shaking so certain facilities can be shut down and/or put into safety mode,” he said. “This includes things such as high-speed trains, large industrial facilities, airports and nuclear power stations.”

However, the Berkeley seismologists say once enough people are using MyShake they plan to warn people kilometres from “ground zero” that tremors are coming their way.

They anticipate an updated app that provides such warnings within a year.

The free app is now available from the Google Play store. An iPhone app is also planned.