September 1998

Heather Sloan and Graham Stewart and their team of mold makers and Museum coworkers travel to Emerson Fault and Anza Borrego State Park in Southern California to make a mold of land displacement along strands of the San Andreas transform fault margin. This fault is the source of major earthquakes in California, and seismicity is a key part of the processes that cause the plates that make up the surface of the Earth to move.

View of the landscape in the Anza Borrego Desert State Park in Southern California, where the Museum's expedition team went to cast rock layers broken and shifted by movement along seismically active faults associated with the San Andreas.

photo credit: Jackie Beckett, © American Museum of Natural History