Aerial view of wrecked cars litter the connector ramp from Interstate 5 to Highway 14 following the Northridge earthquake, on January 17, 1994, in Northridge, California.
(CARLOS SCHIEBECK/AFP/Getty Images)- Temblors total 495 per day, most of them only tiny rumbles on the seismic scale.
- The study analyzed 10 years worth of earthquake data.
- Scientists hope the work will lead to a better understanding of temblors and how to predict them.
Earthquakes are a fact of life in California, but new research has shown that they happen even more often than previously thought.
The new data reveals that at least one earthquake happens every three minutes across Southern California. That equals 495 temblors per day, most of them only tiny rumbles on the seismic scale.
"It's not that we didn't know these small earthquakes were occurring,” Zachary Ross, a seismologist at the California Institute of Technology, said in an article posted on the university’s website. “The problem is that they can be very difficult to spot amid all of the noise.”
The “noise” Ross refers to includes vibrations from all the other things in addition to earthquakes that today’s super-sensitive detectors can record – things like heavy traffic, building construction or large gatherings of people.
(MORE: Watch All the World’s Earthquakes from 1900 - 2000 in One Animation)
Ross is the lead author on a study published this week in the journal Science that examined 10 years worth of earthquake data using new computer technology and a more exact method to separate actual temblors from other background vibrations.
He and his colleagues used a technique known as "template matching." They looked at slightly larger earthquakes that had more easily identifiable signals, or waveform, that had already been recorded and cataloged. They then used those signals as a pattern to find other smaller quakes in the same region.
This April 12, 2019, photo provided by the U.S. Geological Survey shows an earthquake monitoring station near Bakersfield, Calif.
(USGS via AP)When they started their research, the earthquake catalog for the region of Southern California they studied listed 181,000 temblors recorded between 2008 and 2017. After wading through the data and scanning it through high-power computers, that number was increased to 1.8 million.
The nearly 2 million “new” earthquakes range in magnitude from negative 2.0 to 1.7.
The data was collected from an array of detectors near Cahuilla , California. Researchers hope it could help scientists studying earthquakes around the world.
"Seismicity along one fault affects faults and quakes around it, and this newly fleshed-out picture of seismicity in Southern California will give us new insights into how that works," CalTech geophysicist Egill Hauksson, another researcher on the study, said in the university’s article.
The expanded earthquake catalog also shows previously undetected foreshocks that preceded major ones, which researchers hope could lead to new developments in forecasting earthquakes.
“The holy grail of earthquake seismology has always been prediction," Daniel Trugman, a seismologist at Los Alamos National Laboratory who also worked on the study told NPR. "I'm cautiously optimistic that we'll make progress on earthquake prediction.”
https://weather.com/science/news/2019-04-19-new-earthquake-catalog-california
2019-04-19 17:00:11Z
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