  Long sequences of slidings of solid blocks on an inclined rough surface
submitted to small controlled perturbations are examined and scaling relations
are found for the time distribution of slidings between pairs of large events
as well as after and before the largest events. These scaling laws are similar
to the Omori law in seismology but the scaling exponents observed are
different. Log-periodicity correction to the Omori scaling is also found. It is
shown that the scaling behaviors are dependent on the angle that the incline
forms with the horizontal.
