A Reappraisal of Large Earthquake Scaling

Twelve years ago I pointed out that observations indicate that the slip in large earthquakes scales with their length, rather than their width, as expected from the canonical model. Romanowicz (1992) has recently argued that more recent data show that the opposite is true, which has obliged me to re-examine the question. I point out here a defining flaw in her analysis, in that she allowed M0*, the moment at the cross-over from small to large earthquakes, to be a free variable in her curve fitting, whereas this parameter can be defined independently. When this parameter is independently fixed, I find that the updated data set confirms my earlier conclusion that for large crustal earthquakes M0 scales with L2.