The mechanism by which faults interact each other is still a debated matter. One of the main issues is the role of pore-pressure diffusion in the delayed triggering of successive events. The 2016 Amatrice–Visso–Norcia seismic sequence (Central Apennines, Italy) provides a suitable dataset to test different physical mechanisms leading to delayed events. The sequence started on August 24, 2016, with the Amatrice mainshock (M_W = 6), and was followed after more than 60 days by events in Visso (M_W = 5.4) and Norcia (M_W = 5.9). We analyzed the contribution of the static stress change and the role of fluids in the delayed triggering. Through 3D poroelastic modeling, we show that the Amatrice mainshock induced a pore-pressure diffusion and a normal stress reduction in the hypocentral area of the two aftershocks, favoring the rupture. Our parametric study employs a simple two-layered conductivity model with anisotropy in the seismogenic layer, characterized by larger conductivity values (K > 10^–5 m/s) along the NNW-SSE direction. The one-way coupled pore-pressure 3-D diffusion modeling predicts the maximum increase of the pore pressure at the location of the two Visso earthquakes 60 days after the mainshock. The occurrence of anisotropic diffusivity is supported by the pattern of active faults and the strong crustal anisotropy documented by S-wave splitting analysis. We conclude that the temporal evolution of the sequence was controlled by the anisotropic diffusion of pore-pressure perturbations through pre-existing NNW-trending fracture systems.

断层之间相互作用的机制仍然是一个有争议的问题。主要问题之一是孔隙压力扩散在连续事件的延迟触发中的作用。2016年的Amatrice–Visso–Norcia地震序列（意大利中部亚平宁山脉）提供了一个合适的数据集，可以测试导致延迟事件的不同物理机制。该序列于2016年8月24日开始，使用Amatrice主震（中号_{w ^} = 6），并且超过60天后，Visso（中号_{w ^} = 5.4）和Norcia（中号_{w ^}= 5.9）。我们分析了静态应力变化的作用以及流体在延迟触发中的作用。通过3D孔隙弹性建模，我们显示，Amatrice主震在两个余震的下心部位引起了孔隙压力扩散和法向应力减小，有利于破裂。我们的参数研究使用了一个简单的两层电导率模型，在地震发生层中具有各向异性，其特征是电导率值较大（ķ> 10 ^–5 m / s）沿NNW-SSE方向。单向耦合的孔隙压力3-D扩散模型预测在主震发生60天后两次维索地震的位置孔隙压力的最大增加。活动断层的模式和由S波分裂分析证明的强地壳各向异性支持了各向异性扩散率的发生。我们得出的结论是，该序列的时间演化受孔隙压力扰动的各向异性扩散控制，这些孔隙压力扰动是通过已有的ＮＮＷ趋势裂缝系统来实现的。