When an earthquake strikes ... Technically, what [Alex] built is better called a “seismic detector” since it’s not calibrated in any way. It’s just a simple sensor for detecting ground ...

[Andrea] built a seismic wave detector that warns of a possible impending earthquake. Because P waves travel much faster than the “make everything shake” S waves, building a device that ...

The term seismograph usually refers to the combined seismometer and recording device. The first known earthquake detector was invented in 132 A.D. by the Chinese astronomer and mathematician Chang ...