Abstract—The stress-strain state before the М = 7.1 Ridgecrest earthquake in Southern California is analyzed based on spatiotemporal distribution of shear strains calculated in the geomechanical model within local ~100 × 100 km crustal segments at a depth of 3–7 km. In the epicentral zone of the earthquake, starting from three years before the event, a successive series of the time intervals, up to the occurrence of the earthquake, when shear deformations are completely absent and rocks are farthest from ultimate strength—the so-called quiescence zones—are established. The spatial distribution of shear strains in the vicinity of the epicentral zone is analyzed during the quiescence intervals and subsequent bursts of maximum amplitude in the epicentral zone itself. The time intervals of the bursts are called excursions. The successive emergence of maxima in shear strain amplitudes in the epicentral zone and surrounding medium during the excursions corresponds to the situation of a swing when the entire preparation region of a future earthquake is rocking up to the moment of event. Consistency of the obtained results with the existing theoretical models of earthquake preparation is discussed.

摘要— М之前的应力应变状态= 7.1 南加州 Ridgecrest 地震是基于地质力学模型中计算的剪切应变的时空分布进行分析的，这些剪切应变在当地约 100 × 100 公里地壳段中，深度为 3-7 公里。在地震的震中区，从事件发生前的三年开始，连续一系列的时间间隔，直到地震发生，此时完全没有剪切变形，岩石离极限强度最远——所谓的静止区——建立。在静止间隔和随后的震中区本身的最大振幅爆发期间，分析了震中区附近剪切应变的空间分布。突发的时间间隔称为偏移。在偏移过程中，震中区和周围介质中剪切应变幅值的最大值的连续出现对应于当未来地震的整个准备区摇摆到事件时刻时的摆动情况。讨论了所得结果与现有地震准备理论模型的一致性。