Nobuaki Fuji

Improvement of accuracy of the spectral element method for elastic wave computation using modified numerical integration operators

Abstract We introduce new numerical integration operators which compose the mass and stiffness matrices of a modified spectral element method for simulation of elastic wave propagation. While these operators use the same quadrature nodes as does the original spectral element method, they are designed in order that their lower-order contributions to the numerical dispersion error cancel each other. As a result, the modified spectral element method yields two extra-orders of accuracy, and is comparable to the original method of one order higher. The theoretical results are confirmed by numerical dispersion analysis and examples of computation of waveforms using our operators. Replacing the ordinary operators by those proposed in this study could be a non-expensive solution to improve the accuracy.

A hybrid technique for 3-D modeling of high frequency teleseismic body waves in the Earth

In the last decade, the deployment of dense regional arrays such as the USArray transportable array has considerably improved our capacity to image the interior of the Earth.