Reuters | Early Los Angeles-area quakes linked with oil production Reuters The report suggested four major Los Angeles-area quakes in 1920, 1929, 1930 and 1933 were triggered by early drilling methods in which oil was extracted without water being pumped into the ground to replace it, causing the ground to subside. This could ... Oil drilling may have caused deadly 1933 California quake, study by US Geological Survey suggests Oil Production Could Have Caused Century-Old California Earthquakes Some Los Angeles earthquakes possibly triggered by oil production in early 20th century |