Waves in the Earth’s crust are often generated by fractures in the process of their sliding or propagation. Conversely, the waves can trigger fracture sliding or even propagation. The presence of multiple fractures makes geomaterials non-linear. Therefore the analysis of wave propagation and interaction with pre-existing or emerging fractures is central to geophysics. Recently new observations and theoretical concepts were introduced that point out to the limitations of the traditional concept. These are:
• Multiscale nature of waves in geomaterials
• The existence of rotational mechanisms of wave and fracture propagation
• Strong rock and rock mass non-linearity (such as bilinear stress-strain curve with high modulus in compression and low in tension) and its effect on wave propagation
• Apparent negative stiffness associated with either rotation of non-spherical constituents or fracture propagation and its effect on wave propagation
• Active nature of geomaterials (such as seismic emission induced by stress and pressure wave propagation)
• Non-linear diffusion waves, shock waves and hydraulic fracturing
• Synchronization of earhtquakes and volcanic activity
Complex waves are now a key problem of the physical oceanography and atmosphere physics. They are called rogue or freak waves. It may be expected that similar waves are also present in non-linear solids (e.g., granular materials), which suggests the existence of new types of seismic waves.
It is anticipated that studying these and related phenomena can lead to breakthroughs in understanding of the stress transfer and multiscale failure processes in the Earth's crust, ocean and atmosphere and facilitate developing better prediction and monitoring methods.
The session is designed as a forum for discussing these and relevant topics.
All submitted presentation are downloadable, please browse through them before the session. It is a good idea to write the questions in advance to safe time in this rather short session.
We would like to thank all participants for interesting presentations and stimulating questions. The format of the session presented a new and challenging experience, but there are few positive moments that can be pointed out. Firstly, it was democratic – no division between posters and orals. Secondly, we are given time and opportunity to look at the presentations in advance and formulate the questions. Finally, we were able to “talk” and ask questions at the same time without waiting for the one’s turn. This may look not to be easy for the presenter, but even then the presenter has the freedom to choose the question to answer and the order of answering. Yet, let us hope that we will meet in person next year.