  The dynamic energy balance is essential for earthquake studies. The energy
balance approach is one of the most famous developments in fracture mechanics.
To interpret seismological data, crack models and sliding on a frictional
surface (fault) models are widely used. The macroscopically observable energy
budget and the microscopic processes can be related through the fracture energy
$G_c$. The fault surface morphology is the direct result of the microscopic
processes near the crack tip or on the frictional interface. Here we show that
the dynamic energy balance in earthquakes can be expressed by fault surface
morphology, and that they are quantitatively linked. The direct shear
experiments proves the predictions of the theoretical discussions, and show
that the strain rate has crucial influence on the dynamic energy balance.
