A seismograph in your pocket

If you've got an Android cellphone, it will now be part of a network of detectors able to give you advance warning of earthquakes. Google, in partnership with the United States Geological Survey, is trialling the technology in New Zealand and Greece. The service uses your phone's movement sensor, or accelerometer, the technology that keeps pictures or videos the right way up even when you rotate your phone. That same technology can also detect earthquake waves rippling through the ground, effectively turning your phone into a pocket seismograph. Google hopes by harnessing Android cellphones it will be able to crowdsource the world's largest earthquake detection network. Kathryn speaks with Robert de Groot, a US Geological Survey earthquake scientist.