Statistical mechanics in earth physics and natural hazards: Preface to the Topical Issue

There is a wide range of problem in geophysics, from earthquake prediction to the driving forces of plate tectonics, where it is necessary to understand how the Earth works. Despite the large amount of experimental data and the considerable effort undertaken, many questions about fracture and physics of earthquakes have not yet been answered. Fracture and the physics of earthquakes is a subject with many unknowns. It is true that we have a good understanding of the propagation of seismic waves through the Earth and that, given a large set of seismographic records, we are able to reconstruct a posteriori the history of the fault rupture. However, when we consider the physical processes which lead to the initiation of rupture with a subsequent slip and its growth through a fault system to give rise to an earthquake, then our knowledge is really limited.