Transmission Loss of Low Frequency Underwater Sound in the Cayman Trough (CHURCH GABBRO Technical Note)

1974 ◽  
Author(s):  
Scott C. Daubin
Keyword(s):  
Transmission Loss ◽  
Low Frequency ◽  
Technical Note ◽  
Underwater Sound

Hydroacoustic measurements of the 2004 submarine eruption near Nightingale Island, Tristan da Cunha

2020 ◽  
Author(s):  
Dirk Metz ◽  
Ingo Grevemeyer ◽  
Marion Jegen ◽  
Wolfram Geissler ◽  
Julien Vergoz
Keyword(s):  
Transmission Loss ◽  
Low Frequency ◽  
Global Ocean ◽  
Underwater Sound ◽  
Seafloor Mapping ◽  
Tristan Da Cunha ◽  
Hydroacoustic Measurements ◽  
Circumpolar Current ◽  
Hydrophone Array ◽  
Test Ban

<p>Little is known about active volcanism in the remote regions of the global ocean. Here, we resort to long‐range acoustic measurements to study the July/August 2004 eruption at Isolde, a submarine volcanic cone in the Tristan da Cunha archipelago, South Atlantic Ocean. Underwater sound phases associated with the event were recorded as far as Cape Leeuwin, Western Australia, where a bottom-moored hydrophone array is operated as part of the International Monitoring System (IMS). IMS hydrophone data in combination with local seismic observations suggest that the center of activity is located east of Nightingale Island, where a recent seafloor mapping campaign aboard R/V Maria S Merian (MSM20/2) has revealed a previously unknown, potentially newly formed stratocone. Transmission loss modeling via the parabolic equation approach indicates that low-frequency sound phases travel at shallow depths near and within the Antarctic Circumpolar Current, thereby avoiding bathymetric interference along the 10,265 km source-receiver path. Our study highlights the potential of the IMS network for the detection and study of future eruptions both at Isolde and elsewhere. Implications for test-ban treaty monitoring and volcano early warning will be discussed.</p>

Response of the Lungs to Low Frequency Underwater Sound.

1994 ◽  
Author(s):  
Peter H. Rogers ◽  
Gary W. Caille ◽  
Thomas N. Lewis
Keyword(s):  
Low Frequency ◽  
Underwater Sound

scholarly journals Spiral Sound Wave Transducer Based on the Longitudinal Vibration

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3674 ◽  
Author(s):  
Wei Lu ◽  
Yu Lan ◽  
Rongzhen Guo ◽  
Qicheng Zhang ◽  
Shichang Li ◽  
...  
Keyword(s):  
Sound Wave ◽  
Longitudinal Vibration ◽  
Three Dimensional ◽  
Low Frequency ◽  
Sound Field ◽  
Field Measurements ◽  
Sound Waves ◽  
Underwater Sound ◽  
Three Dimensional Finite Element ◽  
Wave Transducer

A spiral sound wave transducer comprised of longitudinal vibrating elements has been proposed. This transducer was made from eight uniform radial distributed longitudinal vibrating elements, which could effectively generate low frequency underwater acoustic spiral waves. We discuss the production theory of spiral sound waves, which could be synthesized by two orthogonal acoustic dipoles with a phase difference of 90 degrees. The excitation voltage distribution of the transducer for emitting a spiral sound wave and the measurement method for the transducer is given. Three-dimensional finite element modeling (FEM)of the transducer was established for simulating the vibration modes and the acoustic characteristics of the transducers. Further, we fabricated a spiral sound wave transducer based on our design and simulations. It was found that the resonance frequency of the transducer was 10.8 kHz and that the transmitting voltage resonance was 140.5 dB. The underwater sound field measurements demonstrate that our designed transducer based on the longitudinal elements could successfully generate spiral sound waves.

scholarly journals Low‐frequency propagation across the East Greenland and Frontal Zone: Depth dependence of transmission loss

1987 ◽  
Vol 82 (S1) ◽  
pp. S31-S31
Author(s):  
Leonard E. Mellberg ◽  
D. N. Connors ◽  
D. G. Browning ◽  
G. Botseas ◽  
O. M. Johannessen
Keyword(s):  
Frontal Zone ◽  
Transmission Loss ◽  
Low Frequency ◽  
East Greenland ◽  
Depth Dependence ◽  
Zone Depth

Using arrays of air-filled resonators to attenuate low frequency underwater sound

2015 ◽  
Author(s):  
Kevin M. Lee ◽  
Andrew R. McNeese ◽  
Preston S. Wilson ◽  
Mark S. Wochner
Keyword(s):  
Low Frequency ◽  
Underwater Sound
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