Imaging and characterizing the waste materials inside an underground storage tank using seismic normal modes. Annual progress report, September 15, 1996--September 14, 1997

'This report covers the initial year of investigation of the normal modes of oscillation of underground storage tanks. This work is directed toward finding a way to estimate the properties of the waste in tanks on the Hanford Reservation with the minimal use of instrumentation in a tank. Theoretical work, as well as laboratory-sized physical modeling was undertaken this first year and the satisfying corroboration between the two methods has given us confidence to go forward. The physical model results presented here are for a tank containing a single layer of liquid wastes, while the theoretical formulation is valid for both the single-layer and multi-layer cases. Given this solid foundation the authors proceed to tanks containing multiple layers of solids.