Fig. 7: The role of rheology for on-fault vs. distributed seismicity.
From: Rock and fault rheology explain differences between on fault and distributed seismicity
Cataclasis and slip localization along major normal faults produce fault rocks with frictional properties that promote earthquake nucleation via their stick-slip behaviour. Within the Triassic Evaporites, TE, during the seismic sequence enhanced ductile deformation of the anhydrites and fluid overpressure favour distributed fracturing and faulting of dolostones, brittle failure of anhydrites and reactivation of small displacement faults. On-fault and distributed seismicity are reported with grey and red stars respectively. Distributed deformation on large rock volumes of TE is associated to higher b-values of the earthquake frequency(F)-magnitude(M) distribution whereas on-fault seismicity is characterized by lower b-values.
