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Multiple-Array Detection, Association and Location of Infrasound and Seismo-Acoustic Events - Utilization of Ground-Truth Information
SOUTHERN METHODIST UNIV DALLAS TX
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This work is intended to provide automated methodology for processing seismic and infrasound data from seismo-acoustic arrays and to apply the methodology to regional networks for validation with ground truth information. As reported last year, the project has developed automated techniques for detecting, associating and locating infrasound signals. Work reported this year focuses on refinement of both the detection and location component of the program. Ground truth information developed on the Korean Peninsula is further used to refine the methodology. New location developments are underway. We are incorporating an infrasonic grid-search location method into a Bayesian framework that provides conditional probabilities on the location given the observed data inter-array time delays and backazimuths and a prior distribution. The prior provides ancillary information on the event location, which can be as simple as empirical bounds on backazimuth deviations and group velocities. However, we are investigating extending this simple approach through the use of a 3D ray-tracing algorithm to impose more specific constraints based on available atmospheric specifications. Finally a set of ground truth seismo-acoustic events have been developed for the Korean Peninsula and include a large number of events from a limestone quarry in the Republic of Korea. In-mine seismic and acoustic observations provide the basis of the detailed ground truth. These events occur daily with multiple events on active days and span nearly two years, providing the basis of assessing spatial and temporal variations in propagation path, including variations in backazimuth as well as phase and group velocity. The reported analyses of these data provide empirical bounding constraints for the location algorithm that is under development.
APPROVED FOR PUBLIC RELEASE