2003/03/31 by Agnès Helmstetter, Agnes Helmstetter, Didier Sornette · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Aftershock #Earthquake Detection and Analysis #Geological and Geochemical Analysis #Geology #Induced seismicity #Seismology #earthquake and tectonic studies #physics.geo-ph
paper · pdf · doi:10.1029/2003gl017670
published as Geophys. Res. Lett., 30, 1576, doi:1029/2003GL017670, 2003 · Latex document of 17 pages + 2 postscript figures
openalex publication_date 2003/06/01 · arxiv created 2003/08/18 · arxiv updated 2015/06/26 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Using the simple ETAS branching model of seismicity, which assumes that each earthquake can trigger other earthquakes, we quantify the role played by the cascade of triggered seismicity in controlling the rate of aftershock decay as well as the overall level of seismicity in the presence of a constant external seismicity source. We show that, in this model, the fraction of earthquakes in the population that are aftershocks is equal to the fraction of aftershocks that are indirectly triggered and is given by the average number of triggered events per earthquake. Previous observations that a significant fraction of earthquakes are triggered earthquakes therefore imply that most aftershocks are indirectly triggered by the mainshock.