Symposium on Localization Phenomena
and Dynamics of Brittle and Granular Media

submitted to EOS

In recent years there has developed an increasing awareness and interest in both physics and geophysics of macroscopic patterns and features that spontaneously form in space and time during the deformation of brittle and granular media. Such features include faults and shear bands in the shearing of brittle and ductile solids and in the deformation of granular media: spontaneous grain size segregation during flow and oscillons and other patterns formed during vibratory excitation. Often these features exhibit self-similarity and their populations have fractal size distributions. These spontaneous formation, or self-organizing, phenomena are hallmarks of what has become known as the physics of complexity. The study of complexity is in its exploratory phase, past its infancy, but nowhere near to where a general understanding of these phenomena can be said to have been achieved. This has made it one of the hottest topics in both geophysics and condensed matter physics.

In order to explore these rapidly unfolding topics, a Symposium on Localization Phenomena and Dynamics of Brittle and Granular Media was held at Columbia University from August 6-9, 1997. The symposium was sponsored by the Columbia Earth Institute and Lamont-Doherty Earth Observatory and organized by the recently formed Center for Nonlinear Earth Systems, a unit of the Earth Institute. The themes of the symposium reflect topics of current research activity within CNES.

The selection of session topics was deliberately eclectic in order to emphasize the overarching similarity in the physics behind diverse systems and to bring together geophysicists and physicist who might otherwise not meet and communicate in the more traditional disciplinary meeting format. The session topics were: Earthquakes and earthquake models, granular media dynamics 1, brittle fracture and faulting, sandpiles and landslides, localization phenomena, granular dynamics 2, and models of geomorphological stuctures and patterns.

There were about 100 attendees at the symposium, equally distributed between U.S. and non-U.S. researchers and between geophysicists and physicists. The organizational plan proved successful, with much less disparity in the approach and language being used for the different session topics that one might have expected. An open-ended discussion policy allowed particularly fruitful exchanges: sessions ofter ran an hour or more late with broad participation by the audience.

In addition to the 34 oral presentations, there where 30 poster presentations made during afternoon and evening sessions. The Extended Abstract Volume for the Symposium has been published electronically and may be read on-line or downloaded from the following web site: