Context Earthquakes correspond to the sudden reactivation of shear slip on pre-existing faults or fractures, releasing the elastic energy stored in the upper crust by tectonic plate motion. Stress is then redistributed, possibly triggering other earthquakes (King et. al, 1994). This cascade process results in swarms, or mainshock-aftershock sequences, that from time to time degenerate into catpar pierre.dublanchet - Thèses hors de l'EDPIF