Prediction of Off-Fault Deformation from Experimental Strike-slip Fault
Structures using the Convolutional Neural Networks
Abstract
Crustal deformation occurs both as localized slip along faults and
distributed deformation off faults; however, we have few robust
estimates of off-fault deformation. Scaled physical experiments simulate
crustal strike-slip faulting and allow direct measurement of fault slip
to regional deformation, quantified as Kinematic Efficiency (KE). We
offer an approach for KE prediction using a 2D Convolutional Neural
Network (CNN) trained directly on images of fault maps produced by
physical experiments. A suite of experiments with different loading rate
and basal boundary conditions, contribute over 13,000 fault maps
throughout strike-slip fault evolution. Strain maps allow us to directly
calculate KE and its uncertainty, utilized in the loss function and
performance metric. The trained CNN achieves 91% accuracy in KE
prediction of an unseen dataset. The application of the CNN trained on
scaled experiments to crustal fault maps provides estimates of off-fault
deformation that overlap available geologic estimates.