Tuesday’s earthquake occurred along a section of the San Andreas fault zone known for having smaller earthquakes as well as larger ones, said Caltech seismologist Egill Hauksson. It’s known as the “San Gorgonio knot,” named because there are so many small faults that intersect there as the San Andreas fault bends from a northwest-southeast direction to an east-west orientation.

Source: Los Angeles Times May 08, 2018 12:12 UTC