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Monday, 22 April 2019 00:00

California experiences an unprecedented earthquake pause

San Andreas Fault-Source: San Andreas Fault-Source:

A new study shows that there is an unprecedented earthquake pause in the 3 major faults with the highest slip ratio in California.

The research was carried out by U.S. Geological Survey researchers Glenn Biasi and Kate Scharer and published in Seismological Research Letters on April 3, 2019.

According to Biasi, there has not been a major ground rupturing in the 3 major faults (San Andreas, San Jacinto and Hayward) for 100 years. After analyzing old recordings of the faults for a 1000-year periods, researchers found that such a pause is very unlikely to occur (the possibility was calculated to 0.3%). This pause cannot be attributed to a statistical error or missing data and, therefore, there is a high possibility for intense earthquake incidents in the fore-coming years.

"Our paper confirms that this hiatus is very improbable and it's our view that our efforts will be better spent considering explanations for this, rather than trying to bend the data to make the hiatus a 'statistically improbable but could happen' kind of thing. We're saying, no, it's not a data problem, it's not a data choice problem, it doesn't matter how you slice this. We just have not had earthquakes that past records predict that we should have had," Biasi said.

An intense seismic activity that included large ground-rupturing earthquakes along those faults started in 1800 and ended in 1918. "If our work is correct, the next century isn't going to be like the last one, but could be more like the century that ended in 1918," Biasi added.

According to the researchers, seismologists should investigate on the causes of the long pause. Maybe, there are unknown interactions between the faults or somehow the mantle and lower crust of earth has affected the seismicity of the region. In any case, there is a high possibility that a large amount of energy has been accumulated in the faults. "We had the flurry of very large earthquakes from 1800 to 1918. It's possible that among them they just wrung out—in the sense of wringing out a dishrag—a tremendous amount of energy out the system," Biasi commented.


Read 164 times Last modified on Monday, 22 April 2019 14:11

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