Tomographic Analysis of the Three-Dimensional Variation of the Seismic Velocity Structure of the Shallow Crust Underlying Southern New England.

摘要

This report describes a study in which tomographic inversion was used to investigate the three-dimensional variation of the seismic velocity structure of the shallow crust underlying southern New England (SNE). Group velocity dispersion curves for Rg waves with periods between 0.5 and 2.0 sec have been published for SNE. Dispersion curves from these studies and from our own analyses were converted to travel time data. Two dimensional tomography was then used to estimate group velocities for blocks into which study areas in SNE tomography was then used to estimate group velocities for blocks into which study areas in SNE were divided. Lateral variation in group velocity across SNE is estimated from these results. A combination of the maximum likelihood inverse and forward modelling is used to determine the vertical velocity structure beneath some of these blocks and for other subregions of SNE.