Fig. 3

Fracture statistics as a function of input P₁₀. A Number of fractures before and after trimming the unconnected fractures to form the backbone network. Note that the line for the backbone fractures reaches the zero fractures at P₁₀ ~ 0.2 m⁻¹, thus defining the percolation threshold. Letters in brackets refer to model names (Table 2). B Number of fracture intersections in the backbone network. Error bars: 3 standard deviations either side of the mean. Models B and D overlap. The vertical axes in each plot in units of thousands (10³). Linear regressions for all models except C1 and C2