USGS Seismologist Robert Graves points to a map showing where two fault lines caused the earthquake and met, at a press conference in response to the 6+ magnitude earthquake that struck near Ridgecrest, at Cal Tech, in Pasadena, Calif., on July 4, 2019.

USGS Seismologist Robert Graves points to a map showing where two fault lines caused the earthquake and met, at a press conference in response to the 6+ magnitude earthquake that struck near Ridgecrest, at Cal Tech, in Pasadena, Calif., on July 4, 2019. (Marcus Yam/Los Angeles Times/TNS)