Monte-Carlo inversion for a global shear-velocity model of the crust and upper mantle

We describe a method to invert surface wave dispersion data for a model of shear velocities with uncertainties in the crust and uppermost mantle. The inversion is a multistep process, constrained by a priori information, that culminates in a Markov-chain Monte-Carlo sampling of model space to yield an ensemble of acceptable models at each spatial node. The model is radially anisotropic in the uppermost mantle to an average depth of about 200 km and is isotropic elsewhere. The method is applied on a 2 2 grid globally to a large data set of fundamental mode surface wave group and phase velocities (Rayleigh group velocity, 16-200 s; Love group velocity, 16-150 s; Rayleigh and Love phase velocity, 40-150 s). The…

• NS
  National Science Foundation

  Awards: 9615139, 9818498
• HU
  Harvard University
• UU
  Universiteit Utrecht
• DT
  Defense Threat Reduction Agency
• OO
  Office of Polar Programs