Broadband Infrasound Signal of a Collapsing Hanging Glacier

A major ice collapse (10,000 ) from a hanging glacier on Mount Eiger, Switzerland was recorded by small aperture array as broadband (0.1–10 Hz) infrasound signal. Array analysis reveals that the high (3 frequency signal is produced moving mass, and its back azimuth variation with time tracks mass trajectory provides mean velocity estimate. Infrasound used to estimate radius, despite overestimating volume, quantitative in near-real time. The low (0.1 oscillation modeled terms of field (wind), which induces surrounding air, producing pressure variations at different elements. These results show how observations may provide information avalanche trajectories, possibly, volume.