Earth Quakes

Study: California fault could cause magnitude-7.4 quake

  • FILE - In this Jan. 17, 1994, file photo, the covered body of Los Angeles Police Officer Clarence Wayne Dean, 46, lies near his motorcycle which plunged off the State Highway 14 overpass that collapsed onto Interstate 5, after a magnitude-6.7 Northridge earthquake in Los Angeles. A new study says an earthquake fault running from San Diego to Los Angeles is capable of producing a magnitude-7.4 temblor that could affect some of the most densely populated areas in California. (AP Photo/Doug Pizac, File)

    FILE - In this Jan. 17, 1994, file photo, the covered body of Los Angeles Police Officer Clarence Wayne Dean, 46, lies near his motorcycle which plunged off the State Highway 14 overpass that collapsed onto Interstate 5, after a magnitude-6.7 Northridge earthquake in Los Angeles. A new study says an earthquake fault running from San Diego to Los Angeles is capable of producing a magnitude-7.4 temblor that could affect some of the most densely populated areas in California. (AP Photo/Doug Pizac, File)  (The Associated Press)

  • FILE - In this March 17, 2014, file photo, Egill Hauksson a Caltech Seismologist talks about an early morning earthquake during a news conference at Caltech in Pasadena, Calif. A new study says an earthquake fault running from San Diego to Los Angeles is capable of producing a magnitude-7.4 temblor that could affect some of the most densely populated areas in California. (AP Photo/Nick Ut, File )

    FILE - In this March 17, 2014, file photo, Egill Hauksson a Caltech Seismologist talks about an early morning earthquake during a news conference at Caltech in Pasadena, Calif. A new study says an earthquake fault running from San Diego to Los Angeles is capable of producing a magnitude-7.4 temblor that could affect some of the most densely populated areas in California. (AP Photo/Nick Ut, File )  (The Associated Press)

  • FILE - In this Sept. 29, 2016, file photo, a map of earthquake faults in part of Southern California is seen as a sample of an earthquake early warning system in the state that is under development, is displayed on a television monitor in the background, during a news conference in Rancho Cordova, Calif. A new study says an earthquake fault running from San Diego to Los Angeles is capable of producing a magnitude-7.4 temblor that could affect some of the most densely populated areas in California. (AP Photo/Rich Pedroncelli, File)

    FILE - In this Sept. 29, 2016, file photo, a map of earthquake faults in part of Southern California is seen as a sample of an earthquake early warning system in the state that is under development, is displayed on a television monitor in the background, during a news conference in Rancho Cordova, Calif. A new study says an earthquake fault running from San Diego to Los Angeles is capable of producing a magnitude-7.4 temblor that could affect some of the most densely populated areas in California. (AP Photo/Rich Pedroncelli, File)  (The Associated Press)

A new study says an earthquake fault running from San Diego to Los Angeles is capable of producing a magnitude-7.4 temblor that could affect some of the most densely populated areas in California.

The study, announced Tuesday, looked at the Newport-Inglewood and the Rose Canyon systems. They'd been considered separate but the study concludes they're one long fault running offshore from San Diego Bay and on land through the Los Angeles basin.

Study lead author Valerie Sahakian says the fault is never more than four miles offshore and even a moderately large quake could have a major impact on the region.

In 1933, a magnitude-6.4 quake struck the Long Beach area, killing 115 people.

The study was conducted by Scripps Institution of Oceanography at the University of California, San Diego.