Flexocompression Beam Analogy Applied to the Calculation of Seismogenic Thickness and Cortical Rupture Prediction

JORGE ARIEL ARIEL MORA 

This paper presents a deterministic geomechanical model to parameterize the spatial variability of seismogenic thickness (h) in basement thrust faults under flat-slab subduction regimes. We develop a physico-mathematical analogy by transforming the elemental elastic approximation into a variable cross-section Timoshenko beam model subjected to tectonic flexocompression. The governing differential equations are solved numerically over a regularized mesh using interseismic strain rates derived from GPS data. The lower seismogenic boundary (zmax) is formulated by coupling the effective stress tensor, deep dehydration-induced pore pressure, and rheological constitutive equations. The model is quantitatively calibrated and validated against hypocentral depths recorded by INPRES, and its integration into probabilistic seismic hazard assessment schemes is discussed.