A multi-institutional study indicates that tectonic stress levels within Southern California's primary fault systems have reached a millennium-high peak, increasing the probability of a multi-fault seismic event.

一项由多个机构参与的研究指出，南加州主要断层系统内的构造压力水平已达到一千年来的最高峰，增加了出现多断层地震事件的可能性。

The research, led by Dr. Liliane Burkhard of the University of Bern and published in the Journal of Geophysical Research: Solid Earth, utilized a four-dimensional physics-based model to analyze the San Andreas and San Jacinto fault systems. By synthesizing a 1,000-year historical record derived from radiocarbon dating, sediment analysis, and dendrochronological anomalies, the team quantified the accumulation of crustal stress. The data reveal that current stress levels have surpassed those recorded at any point since the 11th century, exacerbated by a seismic quiescence persisting since the 1857 Fort Tejon event.

这项研究由伯恩大学的 Dr. Liliane Burkhard 领衔，发表于《地球物理研究杂志：固体地球》(Journal of Geophysical Research: Solid Earth)，利用一个四维物理模型来分析 San Andreas 与 San Jacinto 断层系统。通过综合放射性碳定年法、沉积物分析与年轮异常得出的一千年历史记录，研究团队量化了地壳压力的积累情况。数据揭示，目前的压力水平已超过自 11 世纪以来任何时间点的记录，且 1857 年 Fort Tejon 事件后持续的地震静止状态进一步加剧了这一情况。

Central to the study is the conceptualization of the Cajon Pass as an 'earthquake gate.' This geological junction determines whether a rupture remains isolated within a single fault or propagates across both systems. The researchers posit that the likelihood of a dual-fault rupture is contingent upon the synchronicity of stress levels between the two systems. Historical precedents illustrate this mechanism: the 1812 Wrightwood earthquake demonstrated a cross-junction rupture, whereas the 1857 event remained confined. Current estimates indicate stress levels of 3.6 MPa on the San Jacinto-Bernardino section and 2.8 MPa on the Mojave South section of the San Andreas Fault. The relative proximity of these values suggests a configuration conducive to a multi-fault rupture, which would likely result in significantly higher seismic intensity than a single-fault event.

研究的核心是将 Cajon Pass 概念化为一个「地震之门」。这个地质接合处决定了破裂是保持在单一条断层内，还是会扩散至两个系统。研究人员认为，双断层破裂的可能性取决于两个系统之间压力水平的同步性。历史先例证明了这一机制：1812 年的 Wrightwood 地震展示了跨接合处破裂，而 1857 年的事件则局限在单一条断层内。目前的估算显示，San Jacinto-Bernardino 段的压力水平为 3.6 MPa，而 San Andreas 断层的 Mojave South 段为 2.8 MPa。这两个数值较为接近，表明其配置有利于触发多断层破裂，而这将可能导致显著高于单断层事件的地震强度。

Institutional implications involve the potential for extensive disruption to critical infrastructure and densely populated urban centers, including Los Angeles and the Coachella Valley. While the model provides a high-fidelity representation of the current stress state, the researchers emphasize that these findings do not constitute a temporal prediction of a seismic event. Instead, the data serve as a basis for enhanced hazard assessment and infrastructure planning.

机构层面的影响涉及对关键基础设施与人口密集城市中心（包括洛杉矶与 Coachella Valley）造成大规模破坏的可能性。虽然该模型高度还原了目前的压力状态，但研究人员强调，这些发现并不构成对地震事件发生时间的预测。相反，这些数据将作为加强灾害评估与基础设施规划的基础。

The Southern California fault system is currently in a critically stressed state, with conditions at the Cajon Pass favoring a potentially severe multi-fault rupture.

南加州断层系统目前處於一個壓力極高的狀態，Cajon Pass 的情況有利於出現潛在嚴重多斷層破裂。