High resolution regional crustal models from irregularly distributed data: application to Asia and adjacent areas

We propose a new methodology to obtain crustal models in areas where data is sparse and data spreading is heterogeneous. This new method involves both interpolating the depth to the Moho discontinuity between observations and estimating a velocity–depth curve for the crust at each interpolation location. The Moho observations are interpolated using a remove–compute–restore technique, used in for instance geodesy. Observations are corrected first for Airy type isostasy. The residual observations show less variation than the original observations, making interpolation more reliable. After interpolation, the applied correction is restored to the solution, leading to the final estimate of Moho depth. The crustal velocities have been estimated by fitting a velocity–depth curve through available data at each interpolation location. Uncertainty of the model is assessed, both for the Moho and the velocity model. The method has been applied successfully to Asia. The resulting crustal model is provided in digital form and can be used in various geophysical applications, for instance in assessing rheological properties and strength profiles of the lithosphere, the correcting gravity for the crustal effects, seismic tomography and geothermal modelling.