Rapid Sensitive and Easy Test for Transmissible Diseases

Not Available The objective of this project is to develop a seismic event location procedure that utilizes initial and secondary seismic arrival times computed with the Gaussian beam method. Software to compute Gaussian beam synthetic seismograms for complex three-dimensional velocity structures will be developed. This software will be integrated with existing hypocenter inversion software to produce new event location programs. The Phase I project will use th iterative least-squares inversion method. Software to compute phase travel times and travel-time derivatives from Gaussian beam synthetic seismograms will be developed. A travel-time grid method based on Gaussian beam seismograms will be developed in Phase II. The nonlinear inversion method of Tarantola and Valette will be used to compute the hypocenter and location error estimates. The two location programs using Gaussian beam travel times will be compared to other methods of computing event locations for three-dimensional velocity models. The software developed will have immediate application in the CTBT monitoring effort. Commercial applications include monitoring the induced seismicity in oil fields as well as rock-bursts and collapses in mines, and earthquake hazards reduction.