Scientists in a new study have discovered over a million tiny earthquakes that occurred in Southern California between 2008 and 2017. Many of these were previously unnoticed. This data is important in helping scientists gain more knowledge about what triggers bigger earthquakes.
How the Identification Was Made
The researchers’ findings are reported in this month’s Science. The team used a method known as template machine to explore existing data about earthquake activity in Southern California during a specified time period. One of the major events during this time was the El Mayor-Cucapah earthquake that hit Baja California, Mexico, in 2010. This large earthquake had a magnitude of 7.2 and had many aftershocks.
Using the template matching technique, the researchers have been able to unveil a huge amount of data about smaller earthquakes that occurred in the region between 2008 and 2017. Many of these were triggered by the 2010 earthquake. Previously, the signals produced by these smaller earthquakes were too small to be detected above the noise.
Importance of the Findings
Because of the research, the Southern California Seismic Network archive now has a record of as many as 1.8 million, an almost tenfold increase. The work is significant because it expands the knowledge database on earthquakes in the region. This could prove useful as scientists seek to identify trends and interactions between the smaller earthquakes and the much larger ones.
There is now so much more data available about seismic activity than there was before the study. This allows for better and greater statistical analysis. It has also been revealed that the aftershocks of the 2010 El Mayor-Cucapah extended as far as 275 kilometers from the epicenter, which is 100 kilometers further than previously believed. This has also increased the recorded number of aftershocks by 142%. One of the other takeaways from this is that earthquakes interact in more ways than previously thought.