Researchers discovered that the two faults known as Newport-Inglewood Fault and the Rose Canyon Fault in Southern California, which are assumed to be separated, are just part of a "mega fault" system. This newly discovered mega fault system could pose dangers and could trigger a 7.4 earthquake from Los Angeles to San Diego.
In the past studies, the researchers found that the Newport-Inglewood and Rose Canyon fault zones had gaps with about 4.8 km (3 miles) wide. The researchers thought that these fault lines were not connected for 30 years, according to Science Alert.
On the other hand, the new study discovered that the gaps between the two fault lines were no more than 2 km (1.25 miles) wide. This indicates that the fault zones are connected.
The Newport-Inglewood Fault extends for about 47 miles (76 km) from Culver City southeast to Inglewood and to Newport Beach, in which this point the fault goes along the way to east-southeast into the Pacific Ocean then to the Rose Canyon Fault. Together, the Newport-Inglewood Fault and Rose Canyon Fault are capable of producing an earthquake of 7.3 or 7.4 magnitudes.
Valerie Sahakian, the lead author of the study from the U.S. Geological Survey, said that the intensity of an earthquake depends on the length of the faults. She further said that the longer the fault, the larger the earthquake.
Some parts of the fault zones are underwater. Therefore, the researchers have difficulties in studying them in the past. The researchers said that four main fault strands are detected offshore. These were separated by three chief stepovers along strike, with 2 km or less in width.
In the new study, which was published in The Journal of Geophysical Research, acoustic waves were vaulted off the seafloor to view the sedimentary layers below. The team then merged this data with the seismic surveys collected in the past. They discovered that the fault lines were not as separate as previously thought. This finding could lead to preparation for the possible strong earthquakes in the future.