The Long Beach Array sits atop a segment of the Newport-Inglewood Fault Zone (NIFZ). The 1933 Long Beach earthquake, which caused wide-spread damage in the Los Angeles region occured on this fault just to the SE of the array. Many of the oilfields in the Los Angeles Basin are along the NIFZ.
The geometry and density of the array makes it possible to estimate the
activity on the NIFZ. To do this, we have made a movie of the apparent
micro-slip on the fault. To make a frame in the movie, the data from
the array are back-projected onto the plane of the NIFZ. The result
shows a sense of the activity on the fault. Note that these are very small
motions.