 The total production of gold in California from then till now is estimated at 118 million ounces (3700 t).There were decades of minor earthquakes, more than at any other time in the historical record for Northern California, before the 1906 San Francisco earthquake.Previously interpreted as precursory activity to the 1906 earthquake, they have been found to have a strong seasonal pattern and due to large seasonal sediment loads in coastal bays that overlie faults as a result of mining of gold inland.