Earthquake-like patterns of acoustic emission in crumpled plastic sheets

We report remarkable similarities in the output signal of two distinct out-of- equilibrium physical systems - earthquakes and the intermittent acoustic noise emitted by crum- pled plastic sheets - Biaxially Oriented Polypropylene (BOPP) films. We show that both signals share several statistical properties including the distribution of energy, distribution of energy in- crements for distinct time scales, distribution of return intervals and correlations in the magnitude and sign of energy increments. This analogy is consistent with the concept of universality in com- plex systems and could provide some insight on the mechanisms behind the complex behavior of earthquakes.