Preface

The topic Avalanches in Functional Materials and Geophysics is a highly researched area of science with significant cross-fertilization between approaches in the two fields. Avalanches occur in many physical systems spanning microscopic to macroscopic length scales. Beyond the usual snow avalanches and seismic activity, acoustic emission measurements identify avalanches during phase transitions, the collapse of porous materials under pressure and many other materials related processes. One of the major objectives of the book is to identify common experimental characterization, theoretical and simulation techniques as well as statistical data analysis, and similar predictive modelling and phenomenology in materials science and geophysics. The book is likely to be broadly accessible and caters to beginning researchers, graduate students as well as experts. The book contains a dozen chapters, which represent partly a review with a wide perspective and original research aimed at identifying open issues. The first two chapters invoke the statistical mechanics approach to earthquakes and an associated mean-field theory to study avalanches. A series of simple models of earthquake faults is investigated. The role of fault geometry, friction and noise in determining the statistics of earthquakes is explored. The statistics and the dynamics of slip avalanches in slowly deformed solids are reviewed. These results have implications for materials testing, failure prediction, and hazard prevention. The next three chapters address how to mimic earthquakes in a laboratory setting (“labquakes”) in porous materials as well as geological aspects such as the role of various rock types in earthquakes. A review of recent acoustic emission experiments during the compression of synthetic porous materials under controlled force rates is presented. The statistical analysis of the recorded signals of laboratory experiments allows a comparison with the statistics of earthquakes from available seismic data. Different methods to characterize individual acoustic emission avalanches and their time correlations are discussed. The results indicate that the failure dynamics of materials can be studied by measuring strain drops under slow compression, opening the possibility to study earthquake dynamics in the laboratory at non-ambient conditions.