We study the robustness of self-organized criticality in the coupled map lattice introduced by Olami, Feder, and Christensen [Phys. Rev. Lett. 68, 1224 (1992)] by considering the influence of point and extended defects. Our results indicate that there is a finite range of defect concentrations for which one can observe criticality. Additionally, the study of the Gutenberg-Richter law allowed us to verify that the defect-free model has a smoother behavior than previously predicted.

• Received 28 November 1994

DOI:https://doi.org/10.1103/PhysRevE.52.154