A computer-implemented method of predicting fault seal, comprising: receiving (10A; 10B), at a computer processor, a digital seismic image representative of a subsurface volume of interest including at least one fault surface, wherein the at least one fault surface is represented by a fault seismic signal in the digital seismic image, the fault seismic signal comprising a fault reflection signal; the method characterised in defining a fault coordinate system locally parallel and perpendicular to the at least one fault surface; extracting (14A; 14B) seismic amplitudes from a sub-volume surrounding and containing the at least one fault surface and mapping the seismic amplitudes in the fault coordinate system; performing (16A; 16B) trace fitting of the seismic amplitudes in the fault coordinate system along directions locally perpendicular to the fault surface to obtain best-fit wavelets at fault locations along the fault; comparing the best-fit wavelets derived from trace fitting to at least one of natural analog-data and synthetic models of seismic response to generate a predicted fault seal; and identifying geologic features based on the predicted fault seal, wherein the best-fit wavelets are obtained by systematically searching for the highest trace-fitting quality between a fault reflection trace normal to the fault surface at a fault location and a series of model traces or traces derived from analog-data, where trace-fitting quality is the degree of similarity between two traces, and where analog-data is data from subsurface volumes analogous to the subsurface volume being analyzed, wherein a predicted fault seal predicts if the fault prohibits, impedes or enhances fluid flow in the subsurface volume of interest, and wherein the predicted fault seal is based on relating the best-fit wavelets to differences in: at least one of pore-fluid density, chemical-phase, and pressure across the fault surface; or fault zone thickness and properties within the fault zone; or at least one of rock type, porosity, density and any other physical rock properties across the fault surface. receiving (10A; 10B), at a computer processor, a digital seismic image representative of a subsurface volume of interest including at least one fault surface, wherein the at least one fault surface is represented by a fault seismic signal in the digital seismic image, the fault seismic signal comprising a fault reflection signal; the method characterised in defining a fault coordinate system locally parallel and perpendicular to the at least one fault surface; extracting (14A; 14B) seismic amplitudes from a sub-volume surrounding and containing the at least one fault surface and mapping the seismic amplitudes in the fault coordinate system; performing (16A; 16B) trace fitting of the seismic amplitudes in the fault coordinate system along directions locally perpendicular to the fault surface to obtain best-fit wavelets at fault locations along the fault; comparing the best-fit wavelets derived from trace fitting to at least one of natural analog-data and synthetic models of seismic response to generate a predicted fault seal; and identifying geologic features based on the predicted fault seal, wherein the best-fit wavelets are obtained by systematically searching for the highest trace-fitting quality between a fault reflection trace normal to the fault surface at a fault location and a series of model traces or traces derived from analog-data, where trace-fitting quality is the degree of similarity between two traces, and where analog-data is data from subsurface volumes analogous to the subsurface volume being analyzed, wherein a predicted fault seal predicts if the fault prohibits, impedes or enhances fluid flow in the subsurface volume of interest, and wherein the predicted fault seal is based on relating the best-fit wavelets to differences in: at least one of pore-fluid density, chemical-phase, and pressure across the fault surface; or fault zone thickness and properties within the fault zone; or at least one of rock type, porosity, density and any other physical rock properties across the fault surface. at least one of pore-fluid density, chemical-phase, and pressure across the fault surface; or fault zone thickness and properties within the fault zone; or at least one of rock type, porosity, density and any other physical rock properties across the fault surface.