Download or read book Planning of Deployment of an Autonomous Source for Year Round Acoustic Monitoring of the Arctic Ocean written by A. Gavrilov and published by . This book was released on 1995 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Planning of a year-round experiment on trans-Arctic acoustic transmission in the framework of the program Arctic Climate Observation using Underwater Sound" (ACOUS) is a complex problem involving, not only, scientific and technical issues, but requiring consideration, also, of the financial aspects. According to the ACOUS proposal, the NRAD's vertical array is one which can be used as the first receiving system for the year-round experiment, and this array should be deployed in the Lincoln Sea in the spring of 1996. Therefore, the main problem at the first stage of designing the experiment is to develop an optimum scheme for trans-Arctic acoustic transmissions to the Lincoln Sea.
Download or read book Planning of Deployment of an Autonomous Source for Year Round Acoustic Monitoring of the Arctic Ocean written by A. N. Gavrilov and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Planning of a year-round experiment on trans-Arctic acoustic transmission in the framework of the program Arctic Climate Observation using Underwater Sound" (ACOUS) is a complex problem involving, not only, scientific and technical issues, but requiring consideration, also, of the financial aspects. According to the ACOUS proposal, the NRAD's vertical array is one which can be used as the first receiving system for the year-round experiment, and this array should be deployed in the Lincoln Sea in the spring of 1996. Therefore, the main problem at the first stage of designing the experiment is to develop an optimum scheme for trans-Arctic acoustic transmissions to the Lincoln Sea.
Download or read book Development of the Method for Deployment of an Autonomous Source for Year Round Acoustic Monitoring of the Arctic Ocean the Acoustic Complex for Horizontal Location of an Autonomous Source and Communication of the Navigation Data written by A. Doroshenko and published by . This book was released on 1996 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: In acoustic thermometry of the ocean, interpretation of the results of the measurements implies that all distances between sources and receivers in the thermometry system are fixed during an experiment. This means that the acoustic sources and receivers should be firmly installed on the bottom. However, it is not always possible to deploy such stable systems in the ocean, especially in deep water. One of the acoustic emitting complexes for the ACOUS (Arctic Climate Observation using Underwater Sound) experiment is planned for deployment in the deep-water Central Arctic Basin. Arctic conditions make it difficult to deploy a long-baseline system, since the ice drift cannot be controlled and the navigation beacons cannot be accurately deployed at the determined points on the bottom around the main mooring system. In these conditions, the beacons should be self-locating and the system construction adapted for fast deployment. Moreover, the necessary resolution of the thermometry system in the ACOUS experiment requires positioning accuracy better than that in the available commercial devices. This paper discusses these requirements of the acoustic positioning system as well as addressing the issue of communication between the complex and the shore.
Download or read book Arctic Ocean Long term Acoustic Monitoring written by Ethan H. Roth and published by . This book was released on 2008 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Arctic Ocean has experienced wide-spread decreases in sea ice concentrations that may impact various marine ecosystems. This study analyzes yearlong ocean acoustic recordings from north of Barrow, Alaska, to provide baseline measurements prior to possible increases in anthropogenic activities. In September 2006, two autonomous High-frequency Acoustic Recording Packages (HARPs) were deployed to the seafloor (250m), where sound was continuously recorded by hydrophones for nine months. Ice conditions during the recordings included open water, pack ice formation, shore-fast canopies, and thermal breakup, providing a wide range of Arctic Ocean acoustic measurements. Spectral-averaging was used to determine received sound-pressure levels. Across the low-frequency band, fall was the noisiest season, reaching 87dB re [mu]Pa between 20-60Hz, while 10% of October was exposed to noise above 130dB re [mu]Pa at 10Hz and 112dB re [mu]Pa between 20-30Hz; seismic airguns were present from September to November. Acoustic data was compared with sea ice concentration and wind speed; during summer and fall, sound-pressure spectrum levels correlate directly with high wind speeds, typically indicative of low-pressure atmospheric events. Throughout winter and spring, strong winds and thermal fracturing in sea ice opens leads, resulting in correlations with spectral energy-peaks. Bioacoustic recordings of cetaceans and pinnipeds were analyzed using long-term spectral-averages to determine presence or absence on an hourly basis. Combined with ancillary measurements, long-term acoustic monitoring is an effective tool for observing changing levels of ambient sound related to sea ice dynamics, environmental noise-generating mechanisms, and anthropogenic noise, while simultaneously detecting marine mammals.
Download or read book Report on the Acoustic Network Arctic Deployment written by and published by . This book was released on 1995 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the March 1994 Arctic deployment undertaken by the Acoustic Telemetry Group of WHOI. The deployment was a part of the 1994 Sea Ice Mechanics Initiative (SIMI) project and was based at the west SIMI camp, approximately 150 Nautical miles north-east of Prudhoe Bay, Alaska. The goal of the deployment was to install a network of six high-performance acoustic modems, developed at WHOI, and to obtain a data set demonstrating the communications and acoustic monitoring capabilities of the network. The six modems in the network were deployed over an area of 22 square km and communicated via radio Ethernet with a computer at the SIMI camp. Each modem had a global positioning system, an acoustic source and an 8 element receiving array. The network was operated in a round-robin broadcast mode (i.e., each modern in turn transmitted a packet of data while the others received). The transmissions were 5000 bits-per-second QPSK with a 15kHz carrier. An extensive data set including raw acoustic data, source localization information, and modem position was collected during the deployment. An additional function of the acoustic network was to communicate with, and track, the Odyssey, an autonomous underwater vehicle operated by the Mff group at the SIMI camp. To this end, the Odyssey was equipped with a Datasonics modem configured for periodic QPSK transmission to the network. A data set was obtained from which both the up-link communication and localization capabilities of the network can be determined. (KAR) P. 5.
Download or read book Low Frequency Acoustic Propagation Loss in the Arctic Ocean Results of the Arctic Climate Observations Using Underwater Sound Experiment written by and published by . This book was released on 2004 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustic data from the Arctic Climate Observations using Underwater Sound (ACOUS) experiment are analyzed to determine the correlation between acoustic propagation loss and the seasonal variability of sea ice thickness. The objective of this research is to provide long-term synoptic monitoring of sea ice thickness, an important global climate variable, using acoustic remote sensing. As part of the ACOUS program an autonomous acoustic source deployed northwest of Franz Josef Land transmitted tomographic signals at 20.5 Hz once every four days from October 1998 until December 1999. These signals were received on a vertical array in the Lincoln Sea 1250 km away. Two of the signals transmitted in April 1999 were received on a vertical array at ice camp APLIS in the Chukehi Sea north of Point Barrow, Alaska, at a distance of approximately 2720 kin from the source. Temporal variations of the modal propagation loss are examined. The influence of ice parameters, variations of the sound speed profile, and mode- coupling effects on the propagation losses of individual modes is studied. The experimental results are compared to the results of the earlier experiments and the theoretical prediction using numerical modeling.
Download or read book Initial Arctic Acoustic Source Design Study written by Mark Slavinsky and published by . This book was released on 1995 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first pilot experiment on transarctic underice low-frequency (LF) sound propagation in Arctic Ocean-Transarctic Acoustic Propagation (TAP) experiment was successfully carried out in April, 1994. This experiment was performed by American, Canadian and Russian scientists. The acoustic data provided by tone and complex signals propagation along paths of lengths approx. 900 km and approx. 2600 km were collected within 5 days. The TAP experiment has confirmed the principle possibility of observing rather low temperature water-mass trends and averaged over Arctic ice cover characteristics provided by long-term observation of variable phase, propagation time and amplitude of acoustic signals. Acoustic monitoring of climatic variations and study of temperature noises caused by space-time variability of dynamic processes in the Arctic Ocean will require the arrangement of an acoustic network capable of at least ten year functioning. The new program - Arctic Climate Observations using Underwater Sound (ACOUS) being developed for these purposes implies at the first stage arranging continuous collection of acoustic data on paths similar to TAP experiment during 1996-1997.
Download or read book Passive Acoustic Monitoring of Arctic Cetaceans written by Joshua M. Jones and published by . This book was released on 2021 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Arctic marine mammal habitats are changing rapidly while marine shipping is increasing in some areas of the Arctic. Passive acoustic monitoring can increase understanding of Arctic marine mammal responses to change and to stressors, like ship traffic. The strength of inference from underwater sound recordings is limited by several factors that I address in this dissertation with the aim of improving the usefulness of acoustic monitoring findings for Arctic marine resource management. I provide spatial context for acoustic detections of bowhead whale sounds, enabling direct comparisons of acoustic presence across different locations and environmental conditions. Ice cover and noise substantially reduce the predicted listening area around underwater sound recorders. Spatially normalized acoustic detections reveal that bowhead whales utilize an area at least 140 km north of Alaska during their spring migration, migrating through large areas of >90% sea ice cover. I describe acoustic characteristics of beluga and narwhal echolocation clicks, which differ substantially in frequency content and rhythmic patterns. Sound absorption by seawater and apparent changes in animal orientation strongly affect frequency spectra of recorded clicks. Finally, I measure the underwater soundscape within a narwhal summer habitat and quantify underwater noise added by commercial ship traffic. The natural soundscape, excluding periods with nearby ships, is relatively quiet in an acoustically sheltered fiord. Distant sounds from regional shipping are apparent at a less-sheltered location open to long-range sound propagation. When ships pass the recording locations, sound levels are elevated above the median levels of natural sounds for periods ranging from 30 minutes up to >4 hours with each transit. Icebreaker and tanker ships radiate more underwater noise than general cargo and bulk carrier ships. Ship sounds overlap with common social sounds produced by narwhals and ringed seals at distances of 5 to >30 km from passing ships, possibly interfering with animal communication. Improved detection distance estimates and understanding of detection probability estimation coupled with increased confidence in detection and identification of beluga, narwhal, and bowhead sounds will facilitate passive acoustic density estimation of Arctic marine mammals, investigation of their relationships with habitat, and studies of their behavioral responses to ship traffic.
Download or read book Development and Validation of a Mobile Autonomous Broadband Passive Acoustic Monitoring System for Marine Mammals written by and published by . This book was released on 2009 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our long-range objective is to understand the oceanographic processes that influence the distribution of whales in the ocean. In support of this objective we seek to develop a fully-integrated autonomous acoustic observing system capable of detecting and classifying a wide range of marine mammal vocalizations (from blue whales to beaked whales; 10 Hz - 100 kHz) with proven performance. This work will ultimately improve our ability to predict whale distribution and bolster efforts to mitigate human impacts on marine mammals. Long-endurance oceanographic sampling platforms such as gliders and profiling floats provide a new opportunity for acquiring acoustic signals from marine animals with immediate applications in conservation and mitigation.
Download or read book Deployment of Autonomous Hydrophone Array in the Scotia Sea written by and published by . This book was released on 2008 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The remote area of the Atlantic Ocean near the Antarctic Peninsula and the South Scotia Sea is a region where acoustic surveillance by International Monitoring System (IMS) hydrophones is at best limited. Sound originating in this area is either blocked or hindered by the South Georgia Islands (SGI) and the associated seafloor ridge system, making the region a potential hydroacoustic blind spot for IMS stations. In the spring of 2008, we successfully completed the deployment of a hydrophone array consisting of six autonomous underwater hydrophones (AUHs) in the Scotia Sea area. The array configuration is optimum to study sound propagation through the Antarctic Convergence Zone (ACZ), as well as acoustic blockage and reflection caused by islands and associated seafloor topography. Regional seismo-acoustic signals and episodic harmonic tremor from large icebergs will be utilized as natural sound sources.
Download or read book Proceedings of the Scientific Committee on Oceanic Research written by International Council of Scientific Unions. Scientific Committee on Oceanic Research and published by . This book was released on 1995 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Federal Register written by and published by . This book was released on 2006-07-31 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Marine Mammals and Noise written by W. John Richardson and published by Academic Press. This book was released on 2013-10-22 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many marine mammals communicate by emitting sounds that pass through water. Such sounds can be received across great distances and can influence the behavior of these undersea creatures. In the past few decades, the oceans have become increasingly noisy, as underwater sounds from propellers, sonars, and other human activities make it difficult for marine mammals to communicate. This book discusses, among many other topics, just how well marine mammals hear, how noisy the oceans have become, and what effects these new sounds have on marine mammals. The baseline of ambient noise, the sounds produced by machines and mammals, the sensitivity of marine mammal hearing, and the reactions of marine mammals are also examined. An essential addition to any marine biologist's library, Marine Mammals and Noise will be especially appealing to marine mammalogists, researchers, policy makers and regulators, and marine biologists and oceanographers using sound in their research.
Download or read book Atlas of Submarine Glacial Landforms written by J.A. Dowdeswell and published by Geological Society of London. This book was released on 2016-12-16 with total page 631 pages. Available in PDF, EPUB and Kindle. Book excerpt: New geophysical techniques (multibeam echo sounding and 3D seismics) have revolutionized high-resolution imaging of the modern seafloor and palaeo-shelf surfaces in Arctic and Antarctic waters, generating vast quantities of data and novel insights into sedimentary architecture and past environmental conditions. The Atlas of Submarine Glacial Landforms is a comprehensive and timely summary of the current state of knowledge of these high-latitude glacier-influenced systems. The Atlas presents over 180 contributions describing, illustrating and discussing the full variability of landforms found on the high-latitude glacier-influenced seafloor, from fjords and continental shelves to the continental slope, rise and deep-sea basins beyond. The distribution and geometry of these submarine landforms provide key information on past ice-sheet extent and the direction and nature of ice flow and dynamics. The papers discuss individual seafloor landforms, landform assemblages and entire landsystems from relatively mild to extreme glacimarine climatic settings and on timescales from the modern margins of tidewater glaciers, through Quaternary examples to ancient glaciations in the Late Ordovician.
Download or read book The Ocean Economy in 2030 written by OECD and published by OECD Publishing. This book was released on 2016-04-27 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report explores the growth prospects for the ocean economy, its capacity for future employment creation and innovation, and its role in addressing global challenges. Special attention is devoted to the emerging ocean-based industries.
Download or read book Passive Acoustic Monitoring of Cetaceans written by Walter M. X. Zimmer and published by Cambridge University Press. This book was released on 2011-04-21 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: Passive acoustic monitoring is increasingly used by the scientific community to study, survey and census marine mammals, especially cetaceans, many of which are easier to hear than to see. PAM is also used to support efforts to mitigate potential negative effects of human activities such as ship traffic, military and civilian sonar and offshore exploration. Walter Zimmer provides an integrated approach to PAM, combining physical principles, discussion of technical tools and application-oriented concepts of operations. Additionally, relevant information and tools necessary to assess existing and future PAM systems are presented, with Matlab code used to generate figures and results so readers can reproduce data and modify code to analyse the impact of changes. This allows the principles to be studied whilst discovering potential difficulties and side effects. Aimed at graduate students and researchers, the book provides all information and tools necessary to gain a comprehensive understanding of this interdisciplinary subject.
Download or read book Responding to Oil Spills in the U S Arctic Marine Environment written by National Research Council and published by National Academies Press. This book was released on 2014-08-01 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: U.S. Arctic waters north of the Bering Strait and west of the Canadian border encompass a vast area that is usually ice covered for much of the year, but is increasingly experiencing longer periods and larger areas of open water due to climate change. Sparsely inhabited with a wide variety of ecosystems found nowhere else, this region is vulnerable to damage from human activities. As oil and gas, shipping, and tourism activities increase, the possibilities of an oil spill also increase. How can we best prepare to respond to such an event in this challenging environment? Responding to Oil Spills in the U.S. Arctic Marine Environment reviews the current state of the science regarding oil spill response and environmental assessment in the Arctic region north of the Bering Strait, with emphasis on the potential impacts in U.S. waters. This report describes the unique ecosystems and environment of the Arctic and makes recommendations to provide an effective response effort in these challenging conditions. According to Responding to Oil Spills in the U.S. Arctic Marine Environment, a full range of proven oil spill response technologies is needed in order to minimize the impacts on people and sensitive ecosystems. This report identifies key oil spill research priorities, critical data and monitoring needs, mitigation strategies, and important operational and logistical issues. The Arctic acts as an integrating, regulating, and mediating component of the physical, atmospheric and cryospheric systems that govern life on Earth. Not only does the Arctic serve as regulator of many of the Earth's large-scale systems and processes, but it is also an area where choices made have substantial impact on life and choices everywhere on planet Earth. This report's recommendations will assist environmentalists, industry, state and local policymakers, and anyone interested in the future of this special region to preserve and protect it from damaging oil spills.
