Tensor-guided fitting of subducting slab depths

Earthquakes and active-source seismic surveys provide estimates of depths of subducting slabs, but only at scattered locations. Constructing a useful 3D model of slab geometry involves fitting the depth estimates with a uniformly sampled function of space. The method used to fit the data should account for the curvature of the earth’s surface as well as data uncertainties. In addition to estimates of depths from earthquake locations, focal mechanisms of subduction zone earthquakes also provide estimates of the strikes of the subducting slab on which they occur. We use estimated strike directions and the earth’s curved surface geometry to infer a model for spatial correlation that guides a blended neighbor interpolation of slab depths. The interpolation method is then modified to account for the uncertainties associated with the depth estimates.