This research is to do a broadband seismic study of the Earth's mantle using a combination of ScS reverberations and traditional passive-seismic methods, such as fundamental and higher-mode surface-wave dispersion, regional phase, and mode-converted phase analyses. Digital data sets from the IRIS, GDSN, Chinese digital seismic network, RSTN, and Geoscope networks will be utilized. The transition width and lateral continuity of mantle discontinuities will be mapped and applied to questions of the extent of the continental roots and how discontinuities are dominated by chemical versus phase change transitions.
