Although mining remained the focus of the Division of Mines , emphasis began to grow in basic geologic products through the 1940s and 1950s . In 1961 , the name was changed to Division of Mines and Geology ( DMG ) , with a greater emphasis on environmental geology in urban areas . Following the 1971 San Fernando earthquake , DMG was authorized to delineate regulatory zones along faults and install instruments to record earthquake strong motion . In 1976 , it was authorized to help assure reclamation of mined lands , and in 1990 to delineate regulatory zones for liquefaction , earthquake-triggered landslides , and tsunamis . In January 1991 , reclamation-related responsibilities were moved to a new Office of Mine Reclamation . In 2002 , the Division unofficially began using the name California Geological Survey , a change that was formally authorized in 2006 by the California Legislature
1971 San Fernando earthquake
1971 San Fernando earthquake
California Department of Conservation