A network of vertical static pendulums (tiltmeters) has been in operation in Central Europe since July 2007. Hundred and eighty three seismic events of magnitude 7 and greater have occurred worldwide (EMSC) during the ten-year period. Several kinds of tilt anomalies were recognised within days up to months before the mainshocks. The most typical anomaly was a sudden tilting, parallel with the geologic structure, where the pendulum was installed. Based on the observations, we are proposing an asperity model, explaining the generation of so called “stress waves” before the mainshocks. Such stress waves of very low frequency (i.e. periods of days up to the first months) could be detected anywhere on the globe, especially on active geological structures, parallel with the fault, where a mainshock can happen. The observations suggest that we could estimate that part of the global fault system, which generates the detected stress wave, and which reaches the critical state. The estimation can be performed according to the amplitude of the stress wave, compared with stress waves detected on other structures of different orientations. According to the length of the stress wave (its period) and the tilt amplitude, it could be possible to estimate the magnitude of the mainshock.

自2007年7月以来，垂直静态摆锤（倾斜仪）网络已在中欧投入使用。在十年期间，全球发生了783次7级及以上的地震事件（EMSC）。在主震发生前数月至数月之内，已识别出几种倾斜异常。最典型的异常是突然倾斜，与安装钟摆的地质结构平行。基于这些观察，我们提出了一个粗糙模型，解释了主震之前所谓的“应力波”的产生。这种频率非常低的应力波（即直到最初几个月的几天）可以在全球任何地方被检测到，尤其是在与断层平行的活动地质结构上，可能会发生主震。观察结果表明，我们可以估计全球断层系统的那部分，该部分会生成检测到的应力波，并达到临界状态。与在不同方向的其他结构上检测到的应力波相比，可以根据应力波的幅度执行估计。根据应力波的长度（其周期）和倾斜幅度，可以估计主震的大小。