Scientists identify early tremor pattern to help predict earthquakes

Cracks in the July 4, 2019 earthquake along Highway 178 from Ridgecrest to Trona, California. FREDERIC J. BROWN / AFP via Getty Images

Earthquakes are historically difficult to predict because there are no clear patterns and the moving and colliding tectonic plates occur over long periods of time. If they could be better predicted, many injuries and deaths could be avoided.

Now, an international team led by scientists Jackson School of Geosciences A lab at the University of Texas at Austin (UT Austin) has successfully isolated a form of „foreshock” tremor, according to a press release from UT Austin. Knowing what this small pre-earthquake tremor looks like gives hope for future predictions.

„If we’re ever going to predict or predict earthquakes, we need to measure, characterize and understand what’s happening before the earthquake,” said study leader Chaz Bolton, who conducted the research while a graduate student at UT. Institute of Geophysics (UTIG), in press release. Bolton is currently a research associate in UT Austin’s Bureau of Economic Geography. Both UTIG and the bureau are part of the Jackson School of Geosciences.

The study„Foreshock properties illuminate nuclear processes of slow and fast laboratory earthquakes,” published in the journal Natural communication.

Now that the research team has identified the pattern of pre-shock tremors, they can replicate them in the real world. Bolton will begin that work in Texas, where the hope is to isolate similar patterns from measurements made by TexNet, the state’s seismic network, according to the news release.

“Earthquakes occur in an irregular cycle, making it difficult to know when or where the next one might strike. Although earthquake records show shaking and other geologic motions occur before large earthquakes, earthquake faults produce as many random rumbles as meaningful tremors,” the press release said.

For a long time, scientists have tried to find clues that help predict earthquakes. He approached the problem by using laboratory-generated seismic „noise” of earthquakes to look for patterns.

Using a small fault made at a Penn State laboratory, the research team measured the earthquake cycles it generated. During their tests, the two-inch-long fault produced increasingly strong tremors that got closer and closer to the simulated earthquake. This pattern is different from slow or weak earthquakes.

Bolton said the pattern is significant because the tremors are linked to major earthquakes.

„It gives you a physical description of what controlling precautions are,” Bolton said.

It also provides a model for researchers to observe in the real world.

Locating these patterns is not direct along deep faults hundreds of miles away. However, co-author Demian Safer, director of UTIG, said the findings highlight the importance of linking seismic observations to real-world faults to detect subtle Earth changes.

„If we really want to detect these precursor events, we need sensors and long-term observations that can track these creaks and groans to tell us how the fault behaves leading to failure,” Saffer said in the press release.

Currently, Bolton is using a three-foot-long synthetic bug at UTIG, which he said will help him better understand how it occurs in nature. He conducts these experiments in addition to his research at TexNet, where he looks at tremor sequences associated with earthquakes greater than magnitude five. He said he expects results by next year.

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