The chip that tells your smartphone which way is up has been used to detect earthquake-scale forces accurately. If further testing proves successful, smartphones could be turned into a network of seismometers that together tell emergency services where to respond first.

The testing was done by a pair of seismologists from the National Institute of Geophysics and Volcanology, Antonino D'Alessandro and Giuseppe D'Anna, who initially put forward the proposal in April 2013 in a paper entitled "Can mobile phones be used in strong motion seismology?" and have now published their results in the Bulletin of the Seismological Society of America.

Although the pair found the iPhone chip had "excellent frequency and phase response, comparable with that of some standard FBA accelerometer used in strong motion seismology", it was not senstitive enough to pick up earthquakes of magnitudes of 5 or under and must be near the epicenter of the quake. Earthquakes under 5 on the Richter scale should only cause minimal internal damage, and not result in building collapses, therefore there is still ample argument for using smartphone chips in organisng emergency response networks. "The number of victims following a strong earthquake depends mainly on the intensity of shaking, and the speed of rescue operations," said D'Alessandro. "A real-time urban seismic network can drastically reduce casualties in urban areas immediately following a strong earthquake, by quickly distributing information about the distribution and intensity of ground shaking."

"The rapid development of this technology will lead in the coming years to the development of high sensitivity and low noise digital MEMS sensors that may be replace the current seismic accelerometer used in seismology," the authors predict. Since we'll have more sensitive MEMS sensors soon, it makes sense to carry out these studies now, considering the high penetration of these devices in many at-risk areas including urban centre. "Actually, the main advantage of these sensors is their common use in mobile phones."