NP7.1Unusual waves in geophysics
|Convener: Arcady Dyskin | Co-Conveners: Efim Pelinovsky , Sergey Turuntaev , Elena Pasternak|
Analysing the propagation of stress waves in heterogeneous media with internal reflections and non-linearity as well as in granular materials 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
• Existence of non-reflective waves in the atmosphere and the ocean and the theoretical discovered continuously inhomogeneous media capable of transmitting elastic waves without reflection.
• Evidence of slow transmission of disturbances with velocities in the neighborhood of 1000 km/year
• Evidence of the presence and propagation of rotational waves in geomaterials
• 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
• The presence of apparent negative stiffness associated with rotation of non-spherical constituents and its effect on wave propagation
Unusual 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 solids, which suggests the existence of new types of seismic waves.
It is anticipated that studying these and related phenomena and their interactions can lead to a breakthrough 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. We will welcome presentations on the relevant topics of:
• Multiscale and fractal modeling
• Cosserat, high gradient and non-local continua
• Non-linear waves
• Bilinear and impact oscillators; wave propagation in bilinear media
• Negative stiffness and its effect on stability and wave propagation