  Of particular interest is the detection of precursors of an impending
rupture. Theoretical, numerical studies along with laboratory experiments
indicate that precursory signs of an impending failure are the sudden drop of
fractal dimension and entropy, along with the anticorrelated, for large system
sizes, rising of Hurst exponent and drop of a frequency-size power-law scaling
exponent. Based on the widely accepted concept of the self-affine nature of
faulting and fracture, we examine whether these precursory signs exist in the
fracto-electromagnetic emissions resulting from the activation of a single
fault.
