4 things to know about California's strange earthquake drought

What's up in earthquake country?
A compelling new report authored by two U.S. Geological Survey (USGS) researchers found that three powerful California faults have been strangely — almost impossibly — quiet for the last 100 years. Digging into the soil around these faults, Glenn Biasi and Kate Scharer found that big, ground-rupturing earthquakes have been a regular occurrence in the temblor-prone land over the last 1000 years.  
That's what makes the last 100 years so unusual.
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