The ‘Eastern California Shear Zone,’ within which the 4th July shock struck, rivals the San Andreas for great quakes, producing a M~7.6 shock in 1872, a M=7.3 shock in 1992, and a M=7.1 shock in 1999.

The ‘Eastern California Shear Zone,’ within which the 4th July shock struck, rivals the San Andreas for great quakes, producing a M~7.6 shock in 1872, a M=7.3 shock in 1992, and a M=7.1 shock in 1999.

The ‘Eastern California Shear Zone,’ within which the 4th July shock struck, rivals the San Andreas for great quakes, producing a M~7.6 shock in 1872, a M=7.3 shock in 1992, and a M=7.1 shock in 1999.