The Paucity of Supershear Earthquakes on Large Faults Governed by Rate and State Friction

Supershear earthquakes are rare compared to their subshear counterparts, but the cause for paucity remains be understood. We investigate first time prevalence of supershear ruptures across multiple earthquake cycles on long faults using rate-and-state friction and a 2.5D approximation that accounts finite seismogenic width W. find events occur only in narrow range parameters is not commonly observed laboratory experiments, which may explain its rarity nature. Particularly, ratio between direct evolution effects needs low (a/b < 0.4) nucleation length has sufficiently large W, too it causes transition from seismic aseismic slip. Our numerical analytical developments contribute fundamentally understanding state stress over potential hosting earthquakes.