In January, 1994, movement on a fault in the Los Angeles, California area caused the Northridge earthquake. You may have located the epicenter of the earthquake in the previous investigation: Where was that earthquake?

The Northridge epicenter is marked on this map of known faults in the Los Angeles area. The various colored lines show the surface location of major faults in the region. Faults are three-dimensional features, extending between tilted or curved pieces of rock below the surface, so their subsurface shape and location is not clear from this map.

Any of the faults near the epicenter might have been the one that moved in the earthquake. In this investigation, you'll examine data from the earthquake to decide which fault moved.

1. Make a prediction about which fault might have moved during this earthquake. Draw a small arrow on your map pointing to the fault.