With a more accurate route to finding minute earthquakes, scientists counted 1.8 million of the tremblers in Southern California from 2008 to 2017, according to a report in the Science Newspaper on Thursday. The current earthquake catalog for the area covers nearly 180,000 for this decade.
Earthquakes happen when two blocks of earth suddenly slide past each other. California is a seismic hotspot in the Lower 48 for earthquakes due to its numerous faults, including the San Andreas.
The new report averaged a tiny quake every three minutes. Most were below magnitude 1
"It means that the earth is failing all the time," said lead author of the study, Zachary Ross, a seismologist at the California Institute of Technology in Pasadena, California.
Searching for more of these micro-quakes, Ross and his colleagues hope to find swarm shaking patterns and better information about flaws to better understand and possibly even predict the rarer but more dangerous quakes.
"Right now we do not really understand basic things about earthquakes," said Ross. "Everything would be a great help."
Paul Earle, Operations Chief of the National Earthquake Information Center of the US Geological Survey, who does not participate in the study, said the research gives experts "new eyewear for looking at the earth."
To find the minor quakes, the researchers used an older method based on the assumption that earthquakes from certain locations have unique wave patterns. "Somehow like fingerprints," said Susan Hough, USGS seismologist. She was not part of the study, but called it "pretty cool."
The researchers looked for the fingerprints of the quake that would not normally be seen if you were not just looking for them. The devices that seek to shake are so sensitive that they can even detect traffic, construction sites, ocean waves, and major earthquakes around the world, Ross said.
While computing power limited this type of work in the past, the use of a supercomputer and new algorithms allowed the Ross team to do the necessary work to locate the earthquakes in Southern California.
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