Download or read book An acoustic emissions monitoring system for avalanche snowpacks written by Donald McNair and published by . This book was released on 1977 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Acoustic Emissions Monitoring System for Avalanche Snowpacks written by Donald McNair and published by . This book was released on 1977 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Snow Avalanche and Acoustic Emissions written by R. A. Sommerfeld and published by . This book was released on 1983 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book USDA Forest Service Research Note RM written by Rocky Mountain Forest and Range Experiment Station (Fort Collins, Colo.) and published by . This book was released on 1973 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book U S Forest Service Research Note written by United States. Rocky Mountain Forest and Range Experiment Stations, Fort Collins, Colo and published by . This book was released on 1976 with total page 498 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 Selected Water Resources Abstracts written by and published by . This book was released on 1978 with total page 1216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Acoustic Emission and Mechanical Properties of Snow Related to Avalanche Release written by R. L. Brown and published by . This book was released on 1977 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: The project was concerned with evaluation of the physical and mechanical processes associated with snow avalanche initiation. Four separate tasks were involved in this effort: (1) a stress wave study to evaluate the response of snow to transient loads, (2) a slope stability investigation to determine the effectiveness of boundary conditions on slope stability, (3) a material constitutive representation to evaluate material properties for loads characteristically found in snow slopes, and (4) an acoustic emission study to study the process of slab release. Considerable progress was achieved in all portions of the project. An electromagnetic stress wave generator was successfully constructed and tested and tests are now being carried out with this instrument. An equivalent linear viscoelastic model has been formulated for snow for densities, temperatures, and load conditions characteristic of alpine snow slopes. The acoustic emission field study is still gathering data, and a predictable pattern of acoustic emissions appears to be related to the process of fracture and avalanche initiation. The results of this one year project have been reported in seven publications and symposium presentations. (Author).

Download or read book Advances in North American Avalanche Technology 1972 Symposium written by and published by . This book was released on 1973 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Acoustic Emission Monitoring of Pressurized Systems written by W. F. Hartman and published by ASTM International. This book was released on 1979 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1978 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Snow Avalanche Hazards and Mitigation in the United States written by National Research Council and published by National Academies Press. This book was released on 1990-02-01 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present mortality as a result of snow avalanches exceeds the average mortality caused by earthquakes as well as all other forms of slope failure combined. Snow avalanches can range from small amounts of loose snow moving rapidly down a slope to slab avalanches, in which large chunks of snow break off and destroy everything in their path. Although considered a hazard in the United States since the westward expansion in the nineteenth century, in modern times snow avalanches are an increasing concern in recreational mountainous areas. However, programs for snow avalanche hazard mitigation in other countries are far ahead of those in the United States. The book identifies several steps that should be taken by the United States in order to establish guidelines for research, technology transfer, and avalanche legislation and zoning.

Download or read book Avalanches written by and published by . This book was released on 1977 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contributions reviewing the state of the art concerning avalanches

Download or read book Monthly Catalog of United States Government Publications written by United States. Superintendent of Documents and published by . This book was released on 1978 with total page 1228 pages. Available in PDF, EPUB and Kindle. Book excerpt: February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index

Download or read book Forestry Research West written by and published by . This book was released on 1977 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Federal Information Processing Standards Publication written by and published by . This book was released on with total page 1228 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Forestry Research written by and published by . This book was released on 1977 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: