Oil drilling may have induced earthquakes in California a century ago

NPR : Although Southern California has long been known as a natural earthquake hazard, some of the biggest quakes that occurred in the early 20th century may actually have been caused by oil and gas production, according to a new study published in the Bulletin of the Seismological Society of America. To study quakes that occurred during the California oil boom of the 1920s and 1930s, before the advent of modern seismological data collection methods, Susan Hough and Morgan Page of the US Geological Survey used old scientific surveys, instrument data, and newspaper articles. The researchers were able to link several damaging earthquakes during the period 1915–32 with drilling operations around Los Angeles. However, the researchers say their findings are of historical importance only, because the industry practices in use at the time are no longer employed.