The mega-quakes in Turkey this week showcase how a magnitude 7.8 quake could trigger a magnitude 7.5 aftershock on a different fault, with 60 miles of distance between the epicenters.
A similar seismic scenario could occur in California.
Mega-quakes that could rupture the southern San Andreas Fault from near the Mexican border through Los Angeles County and beyond could trigger major aftershocks and shake cities as far away as Sacramento and San Francisco, according to documents and interviews.