Generation and Propagation of Infrasonic Waves
Final rept. 1 Feb 1970-31 Jan 1973
MASSACHUSETTS INST OF TECH CAMBRIDGE
Pagination or Media Count:
A review is given of theoretical studies on infrasound generation and propagation through the atmosphere which were carried out under the contract. These studies include 1 further development and application of a computer program for the prediction of pressure signatures at large distances from nuclear explosions, 2 development of an alternative approximate model for waveform synthesis based on Lambs edge mode, 3 development of a geometrical acoustics theory incorporating nonlinear effects, dispersion, and wave distortion at caustics, and 4 a theoretical model for the prediction of acoustic gravity wave generation by rising and oscillating fireballs. Numerical studies are reviewed which indicate the dependence of far field waveforms on energy yield and burst height. Implications of the Lamb edge mode theory include a new method for estimating energy yield from waveforms and an explanation of amplitude anomalies in terms of focusing or defocusing of horizontal ray paths.