European Geosciences Union General Assembly 2006 Vienna, Austria, 02-07 April 2006
Stefan Nielsen, Shane Murphy
It has been argued that the dominant period Tp derived from the ini-tial seconds of a seismogram, hence only depending on the initial phases of earthquake rupture, seems to scale with the nal size of the earthquake. In the light of classical scaling laws of earthquake sources, where the nal dimensions of the rupture should control slip and risetime, this poses a prob-lem of causality. By taking a closer look at the energy balance of fracture propagation, however, it can be shown that ruptures starting with a longer risetime have more energy to spend, thus, more chances to overcome barriers and to propagate to large distances. According to this principle the scaling dependence could be reversed, and restated as a size probability depending on initial rupture phases. We propose that Tp is linked to risetime Tr, and test the hypothesis numerically.