How Small Earthquakes May Provide Clues About Big Ones

A new study reported in Scientific American reveals Southern California experiences hundreds of earthquakes every day … they are just too tiny to feel, or until now, record. With the discovery of these previously undocumented quakes, scientists hope to piece together useful information and patterns that may help predict bigger, more destructive ones in our future.

According to LA Magazine, “While seismologists long suspected these subtle quakes were happening, they were unable to accurately record them. The tremblors were gentle enough that things like jackhammering in a street could obscure the signatures. The breakthrough came 15 years ago, when they discovered a previously unknown pattern.

It turns out that any two earthquakes that start in the same place make the same waveform shape on a seismometer, even if one is very large and another very gentle. Once they knew that, they could plug in the waveform signatures of larger quakes and look for smaller versions–but one more hurdle remained. Computers of 15 years ago were only powerful enough to analyze small sets of waveforms at a time. Only recent advances in technology have made it possible to fully scour the Southern California Seismic Network archive.”

You can read more about the technology and how scientists plan to put it to good use here.