Passive Acoustic Thermometry Using Low-Frequency Deep Water Noise

2014 ◽  
Author(s):  
Karim G. Sabra
Keyword(s):  
Deep Water ◽  
Low Frequency ◽  
Acoustic Thermometry ◽  
Passive Acoustic

Passive acoustic thermometry of the deep water sound channel using ambient noise

2013 ◽  
Vol 134 (5) ◽  
pp. 3983-3983
Author(s):  
Katherine F. Woolfe ◽  
Shane Lani ◽  
Karim G. Sabra
Keyword(s):  
Deep Water ◽  
Ambient Noise ◽  
Sound Channel ◽  
Acoustic Thermometry ◽  
Passive Acoustic

scholarly journals Red hind Epinephelus guttatus Vocal Repertoire Characterization, Behavior and Temporal Patterns

2020 ◽  
Vol 31 ◽  
pp. GCFI31-GCFI41
Author(s):  
Carlos M. Zayas Santiago ◽  
Richard S. Appeldoorn ◽  
Michelle T. Schärerer-Umpierre ◽  
Juan J. Cruz-Motta
Keyword(s):  
Low Frequency ◽  
Temporal Patterns ◽  
Spawning Aggregations ◽  
Red Hind ◽  
In Captivity ◽  
In The Wild ◽  
Epinephelus Guttatus ◽  
Spatio Temporal ◽  
Passive Acoustic ◽  
Female Call

Passive acoustic monitoring provides a method for studying grouper courtship associated sounds (CAS). For Red Hind (Epinephelus guttatus), this approach has documented spatio—temporal patterns in their spawning aggregations. This study described vocalizations produced by E. guttatus and their respective behavioral contexts in field and laboratory studies. Five sound types were identified, which included 4 calls recorded in captivity and one sound recorded in the wild, labeled as Chorus. Additionally, the Grunt call type recorded was presumed to be produced by a female. Call types consisted of variations and combinations of low frequency (50—450 Hz) pulses, grunts and tonal sounds in different combinations. Common call types exhibited diel and lunar oscillations during the spawning season, with both field and captive recordings peaking daily at 1800 AST and at 8 days after the full moon.

Low frequency acoustic thermometry in the range 4.2–20 K with implications for the value of the gas constant

1979 ◽  
Vol 365 (1722) ◽  
pp. 349-370 ◽  
Keyword(s):  
Low Frequency ◽  
Acoustic Thermometry ◽  
A Value ◽  
New Information ◽  
Thermodynamic Temperatures ◽  
Good Agreement ◽  
Gas Thermometry

Six acoustic isotherms have been plotted in the range 4.2–20 K. When thermodynamic temperatures are calculated from their intercepts on the basis of Batuecas’s value of the gas constant ( R = 8.31441 J mol -1 K -1 ), no significant systematic departure from the results of Berry’s gas thermometry is discernible. If one assumes Berry’s work to be thermodynamically correct and the present work to be thermodynamically linear, a value of the gas constant is implied only (7 ± 27 (lσ)) R / 10 6 higher than that of Batuecas, but 152 R / 10 6 lower than that of Quinn, Colclough & Chandler (Q. C. C.). Such a value is close to that expected from a forthcoming revision of the work of Q. C. C. and is in line with recent criticisms of Rowlinson et al . of their value. If this expectation is borne out gas and acoustic thermometry will be in good agreement in this range. Final results are quoted on the basis of Batuecas’s value of the gas constant and in terms of R to facilitate their recalculation as new information on the value of the gas constant becomes available.

scholarly journals Measuring the Marine Soundscape of the Indian Ocean with Southern Elephant Seals Used as Acoustic Gliders of Opportunity

2017 ◽  
Vol 34 (1) ◽  
pp. 207-223 ◽  
Author(s):  
Dorian Cazau ◽  
Julien Bonnel ◽  
Joffrey Jouma’a ◽  
Yves le Bras ◽  
Christophe Guinet
Keyword(s):  
Indian Ocean ◽  
Low Frequency ◽  
Sound Field ◽  
Elephant Seals ◽  
Ambient Sound ◽  
Southern Elephant Seals ◽  
Operational Systems ◽  
The Indian Ocean ◽  
Passive Acoustic ◽  
Free Ranging

AbstractThe underwater ambient sound field contains quantifiable information about the physical and biological marine environment. The development of operational systems for monitoring in an autonomous way the underwater acoustic signal is necessary for many applications, such as meteorology and biodiversity protection. This paper develops a proof-of-concept study on performing marine soundscape analysis from acoustic passive recordings of free-ranging biologged southern elephant seals (SES). A multivariate multiple linear regression (MMLR) framework is used to predict the measured ambient noise, modeled as a multivariate acoustic response, from SES (depth, speed, and acceleration) and environmental (wind) variables. Results show that the acoustic contributions of SES variables affect mainly low-frequency sound pressure levels (SPLs), while frequency bands above 3 kHz are less corrupted by SES displacement and allow a good measure of the Indian Ocean soundscape. Also, preliminary results toward the development of a mobile embedded weather sensor are presented. In particular, wind speed estimation can be performed from the passive acoustic recordings with an accuracy of 2 m s−1, using a rather simple multiple linear model.

Glider-Based Passive Acoustic Monitoring in the Arctic

2014 ◽  
Vol 48 (5) ◽  
pp. 40-51 ◽  
Author(s):  
Mark F. Baumgartner ◽  
Kathleen M. Stafford ◽  
Peter Winsor ◽  
Hank Statscewich ◽  
David M. Fratantoni
Keyword(s):  
Real Time ◽  
Marine Mammal ◽  
Low Frequency ◽  
Acoustic Monitoring ◽  
Bowhead Whale ◽  
The Arctic ◽  
Mammal Species ◽  
Frequency Detection ◽  
Passive Acoustic ◽  
The Impact

AbstractPersistently poor weather in the Arctic makes traditional marine mammal research from aircraft and ships difficult, yet collecting information on marine mammal distribution and habitat utilization is vital for understanding the impact of climate change on Arctic ecosystems. Moreover, as industrial use of the Arctic increases with the expansion of the open-water summer season, there is an urgent need to monitor the effects of noise from oil and gas exploration and commercial shipping on marine mammals. During September 2013, we deployed a single Slocum glider equipped with a digital acoustic monitoring (DMON) instrument to record and process in situ low-frequency (<5 kHz) audio to characterize marine mammal occurrence and habitat as well as ambient noise in the Chukchi Sea off the northwest coast of Alaska, USA. The DMON was programmed with the low-frequency detection and classification system (LFDCS) to autonomously detect and classify sounds of a variety of Arctic and sub-Arctic marine mammal species. The DMON/LFDCS reported regularly in near real time via Iridium satellite detailed detection data, summary classification information, and spectra of background noise. The spatial distributions of bowhead whale, bearded seal, and walrus call rates were correlated with surface salinity measured by the glider. Bowhead whale and walrus call rates were strongly associated with a warm and salty water mass of Bering Sea origin. With a passive acoustic capability that allows both archival recording and near real-time reporting, we envision ocean gliders will become a standard tool for marine mammal and ocean noise research and monitoring in the Arctic.

scholarly journals Cues, creaks, and decoys: using passive acoustic monitoring as a tool for studying sperm whale depredation

2015 ◽  
Vol 72 (5) ◽  
pp. 1621-1636 ◽  
Author(s):  
Aaron Thode ◽  
Delphine Mathias ◽  
Janice Straley ◽  
Victoria O'Connell ◽  
Linda Behnken ◽  
...  
Keyword(s):  
Low Frequency ◽  
Field Tests ◽  
Sperm Whale ◽  
Acoustic Monitoring ◽  
Sperm Whales ◽  
Passive Acoustic Monitoring ◽  
Long Distance ◽  
Fishing Activity ◽  
Fishing Vessels ◽  
Passive Acoustic

Abstract Since 2003, a collaborative effort (SEASWAP) between fishers, scientists, and managers has researched how Alaskan sperm whales locate demersal longline fishing activity and then depredate sablefish from gear. Sperm whales constantly produce relatively low-frequency biosonar signals whenever foraging; therefore, over the past decade, passive acoustic monitoring (PAM) has become a basic tool, used for both measuring depredation activity and accelerating field tests of potential depredation countermeasures. This paper reviews and summarizes past published PAM research on SEASWAP, and then provides a detailed example of how PAM methods are currently being used to test countermeasures. The review covers two major research thrusts: (i) identifying acoustic outputs of fishing vessels that provide long-distance “cues” that attract whales to fishing activity; and (ii) validating whether distinctive “creak” sounds can be used to quantify and measure depredation rates, using both bioacoustic tags and statistical comparisons between visual and acoustic depredation estimates during federal sablefish surveys. The latter part of the paper then provides an example of how PAM is being used to study a particular potential countermeasure: an “acoustic decoy” which transmits fishing vessel acoustic cues to attract animals away from true fishing activity. The results of an initial 2011 field trial are presented to show how PAM was used to design the decoy signals and monitor the efficacy of the deployment. The ability of PAM to detect both whale presence and depredation behaviour has reduced the need to deploy researchers or other specialists on fishing cruises. Instead, volunteer fishers can deploy “user-friendly” acoustic recorders on their gear, greatly facilitating the testing of various deterrents, and providing the industry and regulators a convenient and unobtrusive tool for monitoring both the scale and long-term spread of this behaviour across the Alaskan fishery.

scholarly journals Passive underwater acoustic evolution of a calving event

2012 ◽  
Vol 53 (60) ◽  
pp. 113-122 ◽  
Author(s):  
Erin C. Pettit
Keyword(s):  
Spectral Characteristics ◽  
Low Frequency ◽  
Acoustic Measurements ◽  
Dynamic Nature ◽  
High Frequencies ◽  
Direct Measurements ◽  
Audible Sound ◽  
Passive Acoustic ◽  
Remotely Sense ◽  
Ocean Boundary

AbstractDirect measurements of processes occurring at the ice–ocean boundary are difficult to acquire because of the dangerous and dynamic nature of the boundary, yet these processes are among the least well understood in glaciology. Because sound travels well through water, passive underwater acoustics offers a method to remotely sense activity at this boundary. Here we present passive acoustic measurements and spectral analysis of the evolution of a subaerial calving event and the subsequent mini-tsunami and seiche at Meares Glacier, Alaska, USA. Using two hydrophones to record sound from 1 to 40 000 Hz, we find that each phase of a calving event has distinctive spectral characteristics. An event begins with an infrasound rumble (1–20 Hz), then the ice fractures (20–100 Hz), falls and impacts the water (200–600 Hz). High-frequency (>10 000 Hz) sound increases in intensity quickly as the iceberg oscillates, creating turbulence, spray and waves. Within 10 s, the low-frequency audible sound dissipates and the mini-tsunami and seiche sounds dominate (infrasound plus high frequencies) and continue for over 10 min. The specific frequencies and duration of each phase of a calving event depend on its size and location and the glacier and fjord characteristics.

Understanding the Dynamic Coupling Effects in Deep Water Floating Structures Using a Simplified Model

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Ying Min Low ◽  
Robin S. Langley
Keyword(s):  
Frequency Domain ◽  
Deep Water ◽  
Time Domain ◽  
Low Frequency ◽  
Wave Frequency ◽  
Computational Time ◽  
Coupled Analysis ◽  
Floating Platform ◽  
Coupling Effects ◽  
Mooring Lines

The global dynamic response of a deep water floating production system needs to be predicted with coupled analysis methods to ensure accuracy and reliability. Two types of coupling can be identified: one is between the floating platform and the mooring lines/risers, while the other is between the mean offset, the wave frequency, and the low frequency motions of the system. At present, it is unfeasible to employ fully coupled time domain analysis on a routine basis due to the prohibitive computational time. This has spurred the development of more efficient methods, including frequency domain approaches. A good understanding of the intricate coupling mechanisms is paramount for making appropriate approximations in an efficient method. To this end, a simplified two degree-of-freedom system representing the surge motion of a vessel and the fundamental vibration mode of the lines is studied for physical insight. Within this framework, the frequency domain equations are rigorously formulated, and the nonlinearities in the restoring forces and drag are statistically linearized. The model allows key coupling effects to be understood; among other things, the equations demonstrate how the wave frequency dynamics of the mooring lines are coupled to the low frequency motions of the vessel. Subsequently, the effects of making certain simplifications are investigated through a series of frequency domain analyses, and comparisons are made to simulations in the time domain. The work highlights the effect of some common approximations, and recommendations are made regarding the development of efficient modeling techniques.

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