The failure of steel liner of pressure shafts of hydropower plants can have catastrophic consequences. The partial or total loss of the liner support’s rigidity is characterized by a local change of the hydro-acoustic properties and creates reflection boundaries for the water waves. This paper presents a new monitoring method for detecting and locating weak reaches by processing reflected water...

The air-sea drag coefficient controls the transfer of momentum from wind to water. In modeling storm surge, this coefficient is a crucial parameter for estimating the surge height. This study uses two strong wind events on Lake Erie to calibrate the drag coefficient using the Coupled Ocean Atmosphere Wave Sediment Transport (COAWST) modeling system and the the Regional Ocean Modeling System (RO...

Analysis of infrasonic pressure waves generated by active volcanoes is essential to the understanding of volcanic explosion dynamics. Unlike seismic waves propagating in the earth, infrasonic airwaves offer a relatively unfiltered representation of source motions at the vent during an eruption. Time-varying acoustic propagation filters caused by changeable atmospheric conditions are minimal for...

The observation of internal solitary waves (ISWs) propagating upstream along a strongly stratified bottom layer on the California shelf is reported. An increased concentration of particulates in the water column accompanies the passage of these ISW packets. The estimated local Richardson number in the bottom vicinity is around 1/4, and a vertical coefficient of eddy diffusivity of order 1022 m2...

The concepts surrounding a Comprehensive Test Ban Treaty can be traced back to the early 50’s and are well described in Sullivan (1998). The verification regime of the Comprehensive Nuclear-Test-Ban Treaty requires the establishment of an International Monitoring System (IMS) based on four different monitoring technologies: seismic, hydroacoustic, infrasound and radionuclide. The first three te...

[1] Beamforming of seismic noise recorded on 150 Southern California stations was used to identify body and surface waves generated by Katrina. Surface wave microseisms are commonly associated with oceanic storms; there are no previous comprehensive body wave observations. The temporal evolution of the surface and body waves was different, indicating a different source mechanism for the two wav...

The concept of controlling seismic waves is in progress and first full-scale experiments had confirmed the interest which we can have for this new axis of research. The possibility of imagining a seismic 2D or 3D metamaterial made of a grid of inclusions or empty boreholes in the soil, interacting with a part of the earthquake signal is becoming realistic. Here we show the dynamic response of a...

The collapse of massive stars not only produces observable outbursts across the entire electromagnetic spectrum but, for Galactic (or near-Galactic) supernovae, detectable signals for ground-based neutrino and gravitational wave detectors. Gravitational waves and neutrinos provide the only means to study the actual engine behind the optical outbursts: the collapsed stellar core. While the neutr...

The sources of shockwave generation include electrohydraulic, electromagnetic and piezoelectric principles. Electrohydraulic shockwaves are high-energy acoustic waves generated under water explosion with high voltage electrode. Shockwave in urology (lithotripsy) is primarily used to disintegrate urolithiasis, whereas shockwave in orthopedics (orthotripsy) is not used to disintegrate tissues, ra...