From geology to seismic parameters in slow faults: new challenges

Abstract

Paleoseismology allows the characterization of seismogenic faults in high strain rates regions but also in areas with moderate rates of deformation like the Iberian Peninsula. There, an important amount of paleoseismic information has been obtained that have allowed the detection of a number of seismic sources and to estimate their seismic potential by constraining some of their seismic parameters, which makes the Seismic Hazard Assessment more realistic. Considering this information, a number of pitfalls and challenges arise, especially in such a moderate strain rates area, and are discussed here. Some issues and questions are: 1) The catalogue of seismic sources only includes the known sources, making the fault map incomplete and SHA uncompleted; 2) How much evidence do we need to properly characterize a paleoearthquake?; 3) How does one account for aseismic behavior?, 4) Do we have complete seismic histories for a specific fault? 5) Do we have long enough seismic histories to characterize the fault behavior? 6) Are slip-rate estimates for a fault comparable or is there a quality factor to weight them? 7) Do the slip rate estimates we have realistically represent the fault behavior?; 8) How do we deal with Maximum magnitude in fault systems? We show examples on how we try to solve some of these new challenges in the Iberian Peninsula.