Analytical and numerical studies on fault populations

$\\$Fault populations develop in space and time. Both analytical and numerical studies are important in order to be able to predict the evolution of fault populations, in particular those in the SISZ and in the TFZ. This work is made in collaboration with Maurizio Bonafede and Maria Elina Belardinelli. Fault populations generally show power-law (or fractal) frequency distributions as regards fracture length and displacement, that is either fracture length and width (for tension fractures) or fracture length and vertical or horizontal displacement (for faults). In addition, there is commonly a linear relationship between the lengths and widths of tension fractures, and between the length and displacements (vertical or horizontal) on faults. For many fracture populations studied in the Holocene lava flows in Iceland there is, however, a very large scatter in the data, so that two fractures of the same length in the same population may have widely different displacements. A model has been developed where this large scatter is partly attributable to the fracture displacements being related to different controlling dimensions. For some fractures the displacement is controlled by the strike dimension, for others by the dip dimension. A manuscript has been submitted on these results.