A new study from several institutions shows that stress levels in Southern California's main fault systems are at their highest point in 1,000 years, which increases the chance of a major earthquake affecting multiple faults.

幾家機構的一項新研究顯示，南加州主要斷層系統的壓力水平處於 1,000 年來的最高點，這增加了發生影響多個斷層的大地震機率。

The research was led by Dr. Liliane Burkhard from the University of Bern and published in the Journal of Geophysical Research: Solid Earth. The team used a physics-based model to analyze the San Andreas and San Jacinto fault systems. By studying 1,000 years of historical data, including sediment analysis and tree rings, they found that current stress levels are higher than any time since the 11th century. This is partly because there has been a long period of seismic silence since the 1857 Fort Tejon earthquake.

這項研究由伯恩大學的 Liliane Burkhard 博士領導，並發表於《地球物理研究期刊：固體地球》（Journal of Geophysical Research: Solid Earth）。研究團隊使用了一個基於物理的模型來分析聖安地列斯（San Andreas）與聖哈辛托（San Jacinto）斷層系統。透過研究 1,000 年的歷史數據，包括沉積物分析與樹輪，他們發現目前的壓力水平高於 11 世紀以來的任何時期。這部分是因為自 1857 年 Fort Tejon 地震以來，經歷了很長一段地震沉寂期。

Researchers describe the Cajon Pass as an 'earthquake gate.' This area determines if an earthquake stays within one fault or spreads across both systems. The team emphasized that a dual-fault rupture is more likely when stress levels in both systems are similar. For example, the 1812 Wrightwood earthquake spread across the junction, whereas the 1857 event did not. Current data shows stress levels of 3.6 MPa and 2.8 MPa; because these numbers are close, a larger, more intense earthquake is more probable.

研究人員將 Cajon Pass 描述為一個「地震門」。這個區域決定了地震是會維持在單一斷層內，還是會擴散到兩個系統。團隊強調，當兩個系統的壓力水平相近時，雙斷層破裂的可能性更高。例如，1812 年的 Wrightwood 地震就擴散到了交接處，而 1857 年的事件則沒有。目前的數據顯示壓力水平為 3.6 MPa 與 2.8 MPa；由於這些數值接近，發生更大且更劇烈地震的可能性較高。

Consequently, this situation could cause serious damage to critical infrastructure and crowded cities like Los Angeles and the Coachella Valley. However, the researchers clarified that their model cannot predict exactly when an earthquake will happen. Instead, they asserted that this information should be used to improve emergency planning and hazard assessments.

因此，這種情況可能會對關鍵基礎設施以及像洛杉磯（Los Angeles）和 Coachella Valley 這樣擁擠的城市造成嚴重損害。然而，研究人員澄清其模型無法準確預測地震發生的時間。相反，他們主張應利用此資訊來改善緊急計劃與災害評估。

The fault systems in Southern California are under extreme stress, and the conditions at Cajon Pass make a severe multi-fault earthquake more likely.

南加州的斷層系統正處於極高壓力，而 Cajon Pass 的情況使得發生嚴重多斷層地震的可能性更高。