Infrasound from the 2009 and 2017 DPRK rocket launches

Supersonic rockets generate low-frequency acoustic waves, that is, infrasound, during the launch and re-entry. Infrasound is routinely observed at infrasound arrays from the International Monitoring System, in place for the verification of the Comprehensive Nuclear-Test-Ban Treaty. Association and source identification are key elements of the...

Deep ocean sound speed characteristics passively derived from the ambient acoustic noise field

The propagation of acoustic waves in the ocean strongly depends on the temperature. Lowfrequency acoustic waves can penetrate the ocean down to depths where few in situ measurements are available. It is therefore attractive to obtain a measure of the deep ocean temperature from acoustic waves. The latter is especially true if the ambient...

Long-range correlations of microseism-band pressure fluctuations in the ocean

We investigate the spatial coherence of underwater ambient noise using a yearlong time-series measured off Ascension Island. Qualitative agreement with observed cross-correlations is achieved using a simple range-dependent model, constrained by earlier, active tomographic studies in the area. In particular, the model correctly predicts the...