Download or read book Avalanche Detection Using Atmospheric Infrasound written by A. J. Bedard and published by . This book was released on 1997 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the phenomena that snow avalanches produce sounds in the 0.5 to 5.0 Hertz range. It also documents testing of an infrasound detection system to detect snow avalanches in the southwest mountains of Colorado. Two infrasound sensors were installed so the direction of the sound could be determined by comparing the phasing and arrival times. Avalanche detection was sometime obscured because of the high mountains nearby diverting the sound and causing clear-air turbulence. Linking sound events with avalanche events was hampered by the fact that the time of actual avalanches could only be determined within a 12-hour period.
Download or read book Infrasound Avalanche Monitoring System Research Evaluation written by Maria Vyas and published by . This book was released on 2009 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Little Cottonwood Canyon Road (SR-210) has one of the highest risks for avalanche activity for almost any road in North America. Until recently, UDOT staff members have generally relied on visual cues to know whether avalanche control operations have successfully triggered slides (the same holds true for naturally occurring slides). However, in poor lighting or blizzard/whiteout conditions, staff cannot visually monitor whether control operations were successful, or if there is still a risk of avalanche. In 2006, UDOT installed an Infrasonic Avalanche Detection system to monitor three locations in Little Cottonwood Canyon. The Infrasonic provides remote sensing of avalanche activity, so that in poor visibility conditions UDOT staff members are aware of whether an avalanche risk remains or not. The purpose of this research is to evaluate the performance and value of the Infrasonic and determine whether it increases the reliability of avalanche control operations, thereby enhancing public safety.
Download or read book Infrasound Monitoring for Atmospheric Studies written by Alexis Le Pichon and published by Springer. This book was released on 2018-10-26 with total page 1167 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the publication of the first volume “Infrasound monitoring for atmospheric studies” published in 2010, significant advances were achieved in the fields of engineering, propagation modelling, and atmospheric remote sensing methods. The global infrasound network, which consists of the International Monitoring Network (IMS) for nuclear test ban verification completed by an increasing number of regional cluster arrays deployed around the globe, has evidenced an unprecedented potential for detecting, locating and characterizing various natural and man-made sources. In recent years, infrasound has evolved into a broad interdisciplinary field encompassing academic disciplines of geophysics and innovative technical and scientific developments. The advances in innovative ground-based instruments, including infrasound inversions for continuous observations of the stratosphere and mesosphere, provide useful insights into the geophysical source phenomenology and atmospheric processes involved. Systematic investigations into low-frequency infrasound signals and the development of complementary observational platforms point out new insights into the dynamics of the middle atmosphere which play a significant role in both tropospheric weather and climate. This monitoring system also provides continuous relevant information about natural hazards with high societal benefits, like on-going volcanic eruptions, surface earthquakes, meteorites or severe weather. With this new edition, researchers and students benefit from a comprehensive content of both fundamental and applied inter-disciplinary topics.
Download or read book Signal Processing for the Detection of Snow Avalanches Using Infrasound written by Timothy J. Colgan and published by . This book was released on 2007 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inter-Mountain Laboratories Inc. of Sheridan, WY has developed an infrasonic avalanche monitoring system that is being used by the Wyoming Department of Transportation on two avalanche slide paths on Teton Pass near Jackson, WY. This study focuses upon the signal processing behind this type of system, and investigates several different signal processing techniques that might be used to improve the reliability and capabilities of such a system. The methods explored are the extraction of reliable features for avalanche detection, and cross-correlation updating techniques that could be used to improve reliability of the system as well as decrease the computational burden of an avalanche detection system.
Download or read book Publications Abstracts written by Environmental Research Laboratories (U.S.) and published by . This book was released on 1991 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental Research Laboratories Publication Abstracts written by Environmental Research Laboratories (U.S.) and published by . This book was released on 1991 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Seismic Methods Applied to the Study of Snow Avalanche Dynamics and Avalanche Formation written by Cristina Pérez Guillén and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Snow avalanches are extended moving sources of infrasonic and seismic energy. The acoustic and seismic wave fields generated by an avalanche is a complex natural phenomenon produced by the interaction of the flow with its environment. Seismic waves are mainly generated by friction and the impacts of the flow on the snow cover and terrain features; whereas the infrasound waves are generated by the interaction of the powder cloud with the air. Nowadays, avalanches are recorded using seismic and infrasound sensors that provide data that can be used to obtain information about the characteristics of the source and the basis processes that govern avalanche dynamics such as erosion and deposition. So far, the knowledge of how all these dynamical processes and the inherent characteristics of avalanches affect the signatures of the signals is limited and thus more quantitative data are require. Additionally, seismic and infrasonic monitoring systems can provide information on the avalanche triggering mechanisms such as, for example, the shaking produced by an earthquake. Few earthquake-generated avalanches have been documented to date, all of them visually or statistically identified. Hence, a complete dataset of such events does not exist. This study aims to enlarge the current application of seismic methods, mainly for snow avalanche research, which in turn, is relevant to improve monitoring systems. A catalogue of thirty-three snow avalanches of different natures is analysed using the seismic signals recorded with a set of seismic sensors at the Vallée de la Sionne test site in Switzerland. A comparative analysis of the seismic measurements and data acquired with other instrumentation such as infrasound sensor, several frequency-modulated continuous wave radars, and weather stations, is presented in each case to complement and validate the results. This thesis presents novel contributions using seismic methods in the research field of avalanche dynamics and in the field of avalanche formation, specifically in the field of avalanche induced by earthquakes. As a first step, the joint analysis of seismic and infrasound data, correlated with radar measurements, provides data of the onset of an avalanche with the arrival of an earthquake. Seismic data were used to quantify energy parameters and changes in the elastic stress field within the snowpack due to the earthquake. This event was compared with two stronger earthquakes that did not trigger any avalanche. The study was complemented by nivo-meteorological data and snow cover simulations. I conclude that when the snowpack is only marginally stable, then the displacement caused by even a small earthquake could be enough to trigger an avalanche. In addition, the analysis of the other two, even stronger, earthquake shows that in stable conditions no avalanche was triggered. Furthermore, in order to better understand the connection between seismic signals and avalanche dynamics, I quantify the seismic signals in a set of seismic indices. For each seismic signal, the duration, peak ground velocity of the envelope, and both the intensity and the frequency content were compared with the avalanche flow regimes and the thicknesses of the snow cover measured using radar measurements, as well as with the avalanche size. The frequency content of the seismic signal can be used to infer the avalanche flow regime and to characterize its internal parts. Furthermore, the seismic signal duration can be correlated to the avalanche size. If the snow cover absorption does not significantly weaken the intensity of the signal, the avalanche size can also be deduced from the peak ground velocity and its intensity. These results show that avalanche characteristics can be feasible inferred using only seismic data. Such analysis can be usefully employed in avalanche monitoring and management."--TDX.
Download or read book Environmental Research Laboratories Publication Abstracts written by Environmental Research Laboratories (U.S.) and published by . This book was released on 1990 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the International Snow Science Workshop 2002 written by International Snow Science Workshop Canada Inc and published by . This book was released on 2003 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of Methodology for Evaluation and Prediction of Avalanche Hazard in the San Juan Mountain Area of Southwestern Colorado written by Richard Ley Armstrong and published by . This book was released on 1974 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes research carried out from August 1973 to August 1974.
Download or read book Development and Application of Tools for Avalanche Forecasting Avalanche Detection and Snowpack Characterization written by Scott Christopher Havens and published by . This book was released on 2014 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Avalanche formation is a complex interaction between the snowpack, weather, and terrain. However, detailed observations typically can only be made at a single point and must be extrapolated over the slope or regional scale. This study aims to provide avalanche forecasters with tools to evaluate the snowpack, avalanche hazard, and avalanche occurrence when manual observations are not feasible. Avalanches that occur within the new storm snow are a prevalent problem for the avalanche forecasters with the Idaho Transportation Department (ITD) along Highway 21. We have implemented a real time SNOw Slope Stability (SNOSS) model that provides an index to the stability of that layer. SNOSS has been run real time starting during the winter of 2011/2012 with model results outputted to a webpage for easy viewing by avalanche forecasters. To further improve the accuracy of SNOSS, the model was evaluated with a large database of avalanches from the Utah Department of Transportation (UDOT). Using weather data and SNOSS results, the probability of an avalanche day producing a natural direct action avalanche was calculated using a Balanced Random Forest (BRF). In the future, we hope that the BRF can provide a probability of an avalanche occurrence given the current weather and snowpack conditions that can be utilized by avalanche forecasters in their normal operations. The concern for avalanche forecasters with highway operations is the threat of an avalanche releasing and hitting a highway. Infrasound generated by an avalanche moving downhill can be detected and tracked using array processing techniques. This will allow avalanche forecasters to evaluate the avalanche hazard more effectively by determining when and where avalanches have occurred. An avalanche detection system has been developed to detect avalanches in near real time using infrasound arrays. The system processes the infrasound data on-site, automatically detects events, and classifies the events using multiple neural networks. If an avalanche has been detected, the system will transmit the necessary information over satellite to be viewed by avalanche forecasters on a webpage."--Boise State University ScholarWorks.
Download or read book Special Report written by and published by . This book was released on 1989 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geohazards written by and published by Elsevier. This book was released on 2023-08-18 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Geophysics, Volume 64 in this ongoing serial, highlights new advances in the field, with this new volume presenting interesting chapters written by an international board of authors and covering topics such as Distributed acoustic sensing, Infrasound array monitoring of mass movements in Alpine regions, and The Hollin Hill Laboratory. Provides the authority and expertise of leading contributors from an international board of authors Presents interesting chapters written by an international board of authors covering topics such as Distributed acoustic sensing, Infrasound array monitoring of mass movements in Alpine regions, and more Updated release includes the latest information in the Advances in Geophysics
Download or read book Infrasound Monitoring for Atmospheric Studies written by Alexis Le Pichon and published by . This book was released on 2010-04-17 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt: The infrasound field, the science of low-frequency acoustic waves, has developed into a broad interdisciplinary field encompassing academic disciplines of physics and recent technical and scientific developments. The infrasound network of the International Monitoring Network (IMS) of the CTBT-Organization has demonstrated its capability for detecting and locating infrasonic sources such as meteorites, volcanic eruptions, earthquakes, auroras, mountain associated waves ... Nearly 70% of the global network is now operational and regional cluster arrays are deployed around the globe. Systematic investigations into low-frequency acoustic signals have evidenced an unprecedented potential of the monitoring of infrasonic waves permanently generated by natural and man-made events. Furthermore, recent studies point out new insights on quantitative relationships between observables and atmospheric specifications, and therefore opening new fields into the mathematics of geophysical inverse problems for atmospheric remote sensing. This volume reviews the most important areas of infrasound, with emphasis on the latest researches and applications, e.g. instrumentation, engineering, signal processing, source monitoring, propagation modeling, atmospheric dynamics, global changes, remote sensing methods. Researchers and students will benefit from a comprehensive content of infrasound related topics, where both fundamental and applied topics are discussed by authors from international institutions, all experts in their fields.
Download or read book Automatic Detection and Denoising of Signals in Large Geophysical Datasets written by Gabriel O. Trisca and published by . This book was released on 2015 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: "To fully understand the complex interactions of various phenomena in the natural world, scientific disciplines such as geology and seismology increasingly rely upon analyzing large amounts of observations. However, data collection is growing at a faster rate than what is currently possible to analyze through traditional approaches. These datasets, supplied by the increasing use of sensors and remote sensing, require specialized computer programs to effectively analyze complex and expansive volumes of data. Elaborating on existing geophysical data processing approaches for infrasound data collected from an avalanche-prone area, this project proposes new techniques for processing large geophysical datasets. These improved techniques take advantage of Graphical Processing Units (GPU) to accelerate floating-point, computationally expensive operations. Additionally, they allow for dividing the workload among nodes in a High Performance Computing cluster yielding a performance speedup of 3.5 times for every additional node added. Finally, a machine learning approach was used to classify events found in the processed data, which demonstrates the potential of automatic real-time avalanche detection. Applications with characteristics similar to infrasound processing are common throughout the earth-sciences, and this work exemplifies the potential of these techniques to an array of science fields. New algorithms for efficient data processing like those presented in this work are fundamental to analyzing large geophysical datasets, as well as to improving the accuracy of computer models across many disciplines."--Boise State University ScholarWorks.
Download or read book Project Skywater written by United States. Atmospheric Water Resources Program and published by . This book was released on 1971 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conference on Mountain Meteorology written by and published by . This book was released on 1998 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
