Uncertainty Analysis in the Joint Inversion of Receiver Function and Surface-Wave Dispersion, Parana Basin, Southeast Brazil

Abstract

The joint inversion of receiver function (RF) and surface-wave dispersion data is popular because it reduces the nonuniqueness of the modeled subsurface- seismic velocities. Whereas various inverse procedures have been used in joint subsur- face imaging, the evaluation of uncertainties in the estimated parameter distribution is usually overlooked or considered qualitatively. We present a quantitative method for determination of uncertainty in velocity models estimated by the joint inversion of RF and surface-wave data by using the prediction of each observation sample to map the objective-function surface and create a statistical distribution of estimated model parameters. The proposed methodology is evaluated in a controlled test using syn- thetic data simulating a realistic shear-wave velocity model. We then apply the method to field data recorded at the POPB seismic station in the Parana Basin, southeast Brazil. The respective range of uncertainty for modeled S-wave velocity distribu- tions in the synthetic and field tests were 0:111-0:412 km=s (2.5%-9.2%), and 0:110-0:341 km=s (2.5%-7.9%).