  Earthquakes are complex phenomena characterized by some fundamental seismic
laws. However, under the framework of brittle fracture in disordered material,
these universal scaling behaviors, especially for critical exponents, are still
far from understood. In this Letter, we study avalanches in compression of a
nonbrittle material, the ductile metallic glass foam. In addition to elasticity
and disorder, more complex inelastic effects can be also introduced by strain
localization in cellular structures. We show that different from brittle
fracture, the additional shear-banding interactions result in novel avalanche
dynamics which successfully reproduce the most fundamental seismic laws,
including the Gutenberg-Richter law, the unified scaling law for the waiting
times, Omori law, and the productivity law. Our results thus demonstrate that
the local plastic slip, that also occurs in natural seismicity (such as strain
localization in fault gouges), constitutes a necessary ingredient to account
for the most fundamental seismic laws.
