Avalanche unstable fracturing formation model
The basic ideas of the avalanche unstable fracture formation (AUF) model were for the first time presented by the scientists of the Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences at the Assembly of International Union of Geodesy and Geophysics in Moscow in 1971 and published in a special issue of Tectonophysics in 1972. Subsequently, numerous laboratory and in situ experiments have validated and elaborated the AUF model. The model builds on the fundamental principles of the long-term strength physics. The model is independent of the scale of a phenomenon and can be used for describing the rupture preparation not only in the earthquake sources of different energy levels but also for the dynamic events in mines and for the failures of engineering structures under long-term loading. Based on the model, the formation of the widespread en-echelon fracture systems is explained. The earthquake preparation process develops gradually suggesting the possibility to forecast the time of a future seismic event. The model substantiates self-evolution of the earthquake process.