Use of improved propagation models to investigate novel infrasound signals

Abstract

The recent availability of improved infrasound propagation modeling tools and the installation of infrasound arrays in regions of sparse cover- age provide new opportunities for analysis of rare signals. Analyses are presented resulting from recent natural and manmade events, and insights are discussed. Events of interest include the train explosion in Iran of February 18, 2004 and the South Asian tsunami event of December 26, 2004. Using near-real-time environmental profiles and infrasound propagation models, it is shown that the predicted travel times, azimuth deviation and signal duration closely match the observed values. As the dataset of such events is small, predictive modeling can be a valuable tool in developing detection strategies for such events and may ultimately lead to a decreased incidence of false alarms in global monitoring.