Complex sentence: Earthquakes in California are common occurrences as the state is located in a major fault zone, known as the San Andreas Fault zone, which cuts across California and forms the tectonic boundary between the Pacific and the North American Plate boundary.
Split into simpler sentences: Earthquakes in California are common occurrences as the State is located in a seismic zone. The State lies in a major fault zone, known as the San Andreas Fault Zone, which cuts across California and forms the tectonic boundary between the Pacific and the North American Plate Boundary.