title: Stick-slip behavior in a continuum-granular experiment.
abstract: We report moment distribution results from a laboratory experiment, similar in character to an isolated strike-slip earthquake fault, consisting of sheared elastic plates separated by a narrow gap filled with a two-dimensional granular medium. Local measurement of strain displacements of the plates at 203 spatial points located adjacent to the gap allows direct determination of the event moments and their spatial and temporal distributions. We show that events consist of spatially coherent, larger motions and spatially extended (noncoherent), smaller events. The noncoherent events have a probability distribution of event moment consistent with an M(-3/2) power law scaling with Poisson-distributed recurrence times. Coherent events have a log-normal moment distribution and mean temporal recurrence. As the applied normal pressure increases, there are more coherent events and their log-normal distribution broadens and shifts to larger average moment.
authors.affiliation: Condensed Matter and Thermal Physics Group and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Drew A
authors.initials: DA
authors.lastname: Geller
authors.affiliation: Condensed Matter and Thermal Physics Group and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Ecke
authors.affiliation: Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Karin A
authors.initials: KA
authors.lastname: Dahmen
authors.affiliation: Condensed Matter and Thermal Physics Group and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Backhaus