Los Angeles has a long history as a place where oil is drawn from the ground, and a new study by the U.S. Geological Survey finds that relationship might be to blame for its infamous earthquakes. The Los Angeles Times reports that the USGS study suggests drilling in a Huntington Beach oil field caused a magnitude 6.3 Long Beach earthquake in 1933 that killed nearly 120 people and is considered "the deadliest seismic event in recorded Southern California history."
The earthquake, occurring at a time when LA was growing in terms of population, was the one that bestowed upon LA its reputation as "earthquake country," the Times wrote in 2008.
The study also indicates that oil drilling might have been responsible for a handful of other earthquakes that occurred in Whittier and Inglewood in the 1920s.
The two scientists who authored the report did so after studying "nearly forgotten state oil drilling records" which covered drilling that occurred between 1900 and 1935, when Los Angeles was a major global producer of oil, the Times says. They found that the epicenters of a few earthquakes were very close to where "significant changes" had occurred in oil production areas nearby.
The Long Beach earthquake, for example, occurred "not long after operators began drilling wells at different angles," the Associated Press reported.
But the findings don’t necessarily have implications for the present. Oil extraction techniques have changed a lot over the years. "It was kind of more of a Wild West industry back a hundred years ago ... People would just pump oil and in some cases the ground would subside—fairly dramatically," report co-author Susan Hough told the Times.
Also, the possible connections between more recent earthquakes and oil drilling have been explored by other scientists, who " have not found any reason" to say that the two are linked now.