A new study reports that the San Andreas Fault in California and the nearby San Jacinto Fault are experiencing tectonic stress at their highest levels in about the past 1,000 years. Researchers say the fault systems are in a “critically loaded” state, meaning parts of the faults are at or above the maximum stress values observed across the period examined. The study also highlights how the faults interact, indicating that a rupture starting on one fault could potentially propagate toward the other. That possibility is discussed in the context of a “through-going” rupture that could involve multiple segments and affect a large area of Southern California. The findings are based on geophysical analysis reported in a study published in the Journal of Geophysical Research: Solid Earth, led by Liliane Burkhard. While the research focuses on stress levels and rupture potential rather than predicting a specific date, it suggests the region has conditions that could increase the likelihood of a major earthquake in the future.