A smartphone can detect a earthquake. The build in seismometer in your Smartphone detect it when placed on a wooden table by seismic graph.
Just open the link on your web browser. You will see a constantly moving waveform, however in the event that you even marginally shake or tilt your cell phone, recreating seismic movement, the chart will catch them continuously much like a seismograph.
The diagram shows variety relying upon shaking of the telephone in view of the introduction of the gadget.