the Whittier and Newport–Inglewood faults that have dictated the seismic behavior within the basin. Earthquakes The Los Angeles basin is still active tectonically and the region continues to experience earthquakes as a result. Due to the number of faults and fault splays, seismic activity is not concentrated in one particular area. The cities that are overlain by the Newport–Inglewood and Whittier fault zones have a higher probability of experiencing seismic activity. The region experiences earthquakes that are mostly mild (magnitude ≤2.25). However moderate earthquakes (magnitude 4.9 to 6.4) have been reported. Earthquakes of moderate magnitude are very infrequent. Basin features The Newport–Inglewood Fault Zone This fault zone is the most notable feature within the basin that is a single strand with local (fault) splays. The fault zone is also marked by low hills, scarps, and ten anticlinal folds in a right-stepping en echelon pattern. It is located in the southwest portion of the basin and is a strike-slip margin. There are several oil fields that run parallel to this fault. The Whittier Fault This fault lies on the eastern border of the basin and mergers with the Elsinore Fault in the canyon of the Santa Ana river, one of the upper branches of the fault. This fault is a reverse right-oblique fault. It is most known for the Whittier, Brea-Olinda, Sansinena, oil fields. There is an anticline that runs parallel to the Whittier fault that is evidence for compressional deformation during the late Miocene to early Pliocene. Thinning and pinch-out of the Pliocene sandstones are evidence for uplift during this same time period. The Anaheim Nose The Anaheim nose is a subsurface feature that was discovered by geophysical surveys and exploratory drilling in 1930. It is a mid-Miocene fault block that revealed a northwest trending ridge of Paleocene age rocks. This structural feature is important because it revealed many oil traps and orientation of the beds indicate the age of subsidence in this portion of the basin. The Wilmington Anticline This particular anticline is the most notable subsurface feature within the basin. Deformation events such as erosion of the uplifted crustal blocks, initiation of various faults, and the development of the submarine channel led to the anticline's formation. Fold initiation began in the late-Miocene to early Pliocene period of deformation. There are many other anticlines within the basin and isopach data suggests that the formation of these folds occurred mostly