Underwater acoustic analysis reveals unique pressure signals associated with aircraft crashes in the sea: revisiting MH370.

Data analysis from the hydroacoustic stations of the Comprehensive Nuclear-Test-Ban Treaty Organization has unveiled distinctive pressure signals linked to aircraft crashes of varying sizes in the ocean. Notably, these signals were detected at distances ranging from two to five thousand kilometres, highlighting the efficacy of underwater acoustic technology in event identification and classification in marine environments. In this study, we investigate the plausibility of an aircraft, such as Malaysian Airlines Flight 370 (MH370), crashing into the sea leaving a discernible pressure signal at distant hydrophones.

Global Tonga tsunami explained by a fast-moving atmospheric source.

Volcanoes can produce tsunamis by means of earthquakes, caldera and flank collapses, pyroclastic flows or underwater explosions. These mechanisms rarely displace enough water to trigger transoceanic tsunamis. Violent volcanic explosions, however, can cause global tsunamis by triggering acoustic-gravity waves that excite the atmosphere-ocean interface.

Earthquake source characterization by machine learning algorithms applied to acoustic signals.

Underwater seismic events generate acoustic radiation (such as acoustic-gravity waves), that carries information about the source and can travel long distances before dissipating. Effective early warning, emergency response, and information dissemination for earthquakes and tsunamis require a rapid characterisation of the fault properties: geometry and dynamics. In this work, we analysed hydrophone recordings of 201 earthquakes, located in the Pacific and the Indian Ocean, by employing acoustic signal processing and classification methods.

Variation of quantified infection rates of mixed samples to enhance rapid testing during an epidemic.

Rapid testing of appropriate samples from patients suspected for a disease during an epidemic, such as the current Coronavirus outbreak, is of a great importance for disease management and control. We propose a method to enhance processing large amounts of collected samples. The method is based on mixing samples in testing tubes (pooling) in a specific configuration, as opposed to testing single samples in each tube, and recognise infected samples from variations of the total infection rates in each tube.

Effect of Water Compressibility, Sea-floor Elasticity, and Field Gravitational Potential on Tsunami Phase Speed.

Tsunamis can propagate thousands of kilometres across the ocean. Precise calculations of arrival times are essential for reliable early warning systems, determination of source and earth properties using the inverse problem, and time series modulation due to frequency dependency of phase speed. Far field observatories show a systematic discrepancy between observed and calculated arrival times.