subject:(Avalanches)

University of Hong Kong

1. 景路; Jing, Lu. Segregation, runout and deposition in debris flow.

Degree: PhD, 2017, University of Hong Kong

► Debris flow is one of the most destructive natural hazards due to its high mobility and long runout. The prediction of its runout distance, deposit… (more)

▼ Debris flow is one of the most destructive natural hazards due to its high mobility and long runout. The prediction of its runout distance, deposit area, and impact pressure on structure are of great importance to hazard mitigation (e.g. the design of debris-resisting barriers). The deposit morphology of debris flow is largely affected by particle-scale mechanisms, such as size segregation. Segregation leads to boulder-rich front and self-formed lateral levees that enhance runout distance. From the macroscopic perspective, rheological properties are controlling parameters for depositional characteristics. Due to the multi-phase and multi-scale nature of debris flow, this thesis employs both continuum and discrete approaches to add in-depth understanding to the processes of segregation, runout and deposition. Size segregation is studied using discrete element method (DEM). A parametric study shows how size ratio, slope angle, volume concentration and inter-particle friction affect the progress and maximum extent of segregation. Statistical analyses link DEM data to the state-of-the-art continuum theory of segregation, which confirms the theoretical consideration that the excess pressure taken by large particles drives their upward movements. A migration mechanism is proposed for large particles: unlike small particles dropping through voids without enduring contacts, large particles undergo more endurable contacts within crowded and anisotropic contact networks; they are subject to shear due to the surface-driven velocity gradient, and are expulsed with necessary rotations. Moreover, since non-slip condition is crucial to the modelling of segregation with DEM, a roughness parameter Ra is proposed to characterise base roughness. A phase transition from slip (Ra < 0.51) to non-slip (Ra > 0.62) regimes is observed with this parameter. Runout and deposition are studied in computational fluid dynamics (CFD) with homogeneous viscoplastic models, which are more relevant to debris flow with high contents of water and fines. Focus is laid on the effect of rheological parameters, i.e. yield stress and viscosity. Numerical results, which are validated against small-scale flume experiments, show that the rapid deposition of debris flow is due to relatively low viscosity, resulting in elongated deposit morphology; high yield stress leads to thick deposits and steep edges. Runout scaling from laboratory to field is established taking yield stress and viscosity into consideration. To understand fluid–particle interactions in debris flow, a numerical framework coupling DEM and CFD is developed, incorporating the volume of fluid (VOF) scheme to track the dynamics of free fluid surface. With the coupled CFD–DEM model, good agreement is achieved in the simulation of a three-phase (i.e. air, water, solid) dambreak experiment. This model will exploit the strengths of both DEM and CFD to explore the interplay between granular segregation and fluid rheology. Future work will focus on developing constitutive models that bridge…

Subjects/Keywords: Debris avalanches

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APA (6^th Edition):

景路; Jing, L. (2017). Segregation, runout and deposition in debris flow. (Doctoral Dissertation). University of Hong Kong. Retrieved from http://hdl.handle.net/10722/241402

Chicago Manual of Style (16^th Edition):

景路; Jing, Lu. “Segregation, runout and deposition in debris flow.” 2017. Doctoral Dissertation, University of Hong Kong. Accessed September 19, 2019. http://hdl.handle.net/10722/241402.

MLA Handbook (7^th Edition):

景路; Jing, Lu. “Segregation, runout and deposition in debris flow.” 2017. Web. 19 Sep 2019.

Vancouver:

景路; Jing L. Segregation, runout and deposition in debris flow. [Internet] [Doctoral dissertation]. University of Hong Kong; 2017. [cited 2019 Sep 19]. Available from: http://hdl.handle.net/10722/241402.

Council of Science Editors:

景路; Jing L. Segregation, runout and deposition in debris flow. [Doctoral Dissertation]. University of Hong Kong; 2017. Available from: http://hdl.handle.net/10722/241402

Montana State University

2. Chesley-Preston, Tara Lea. Patterns of natural avalanche activity associated with new snow water equivalance and upper atmospheric wind direction and speed in the mountains surrounding Gothic, Colorado: Patterns of natural avalanche activity associated with new snow water equivalence and upper atmospheric wind direction and speed in the mountains surrounding Gothic, Colorado.

Degree: College of Letters & Science, 2010, Montana State University

URL: https://scholarworks.montana.edu/xmlui/handle/1/1067

► Snowfall, temperature and wind are three factors that quickly change avalanche conditions. Ridge-top winds have been used to assess avalanche conditions with mixed success due… (more)

▼ Snowfall, temperature and wind are three factors that quickly change avalanche conditions. Ridge-top winds have been used to assess avalanche conditions with mixed success due to high variability. Few analyses have tested the effect upper atmospheric winds have on avalanche conditions. This study attempts to quantify the effect upper atmospheric wind direction and speed have on the spatial pattern of natural avalanching in the mountains near Gothic, Colorado. The Gothic dataset consists of over 3,300 natural avalanches spanning a time period of 33 years. These data are associated with daily new snow water equivalence (SWE) collected at Gothic, as well as 500mb wind direction and speed from the National Centers for Environmental Protection/National Center for Atmospheric Research (NCEP/NCAR) gridded reanalysis project. I hypothesize that prevailing 500mb winds are more likely to be associated with natural avalanches in avalanche paths with a starting zone aspect lee to the prevailing free air winds. In addition, I hypothesize that the odds of a natural avalanche occurring increases with increasing new SWE, increasing 500mb wind speeds, and 500mb wind direction. These hypotheses are tested using simple probability analysis as well as a two-component hurdle model. As expected, avalanche paths lee to the 500mb wind direction have an increased probability of avalanching in relation to paths facing in other directions. However, exceptions do occur, some of which can be explained by cross-loading. The hurdle model results indicate that after accounting for new SWE, 500mb wind speed is significant in determining whether or not a day will be considered an avalanche day. Once a day is determined to be an avalanche day, 500mb wind direction is an important determinant for the daily avalanche hazard after accounting for new SWE. These results have practical significance. They give avalanche forecasters confidence that upper air wind direction is a useful predictor of the pattern of avalanche activity at the valley or mountain range scale, and the exceptions observed show that such predictions cannot be applied at the path scale. These scale issues demonstrate the general nature of backcountry advisories and why they cannot be applied at the scale of individual slopes. Advisors/Committee Members: Chairperson, Graduate Committee: Stephan G. Custer. (advisor).

Subjects/Keywords: Avalanches.; Winds.

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APA (6^th Edition):

Chesley-Preston, T. L. (2010). Patterns of natural avalanche activity associated with new snow water equivalance and upper atmospheric wind direction and speed in the mountains surrounding Gothic, Colorado: Patterns of natural avalanche activity associated with new snow water equivalence and upper atmospheric wind direction and speed in the mountains surrounding Gothic, Colorado. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/1067

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Chesley-Preston, Tara Lea. “Patterns of natural avalanche activity associated with new snow water equivalance and upper atmospheric wind direction and speed in the mountains surrounding Gothic, Colorado: Patterns of natural avalanche activity associated with new snow water equivalence and upper atmospheric wind direction and speed in the mountains surrounding Gothic, Colorado.” 2010. Thesis, Montana State University. Accessed September 19, 2019. https://scholarworks.montana.edu/xmlui/handle/1/1067.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Chesley-Preston, Tara Lea. “Patterns of natural avalanche activity associated with new snow water equivalance and upper atmospheric wind direction and speed in the mountains surrounding Gothic, Colorado: Patterns of natural avalanche activity associated with new snow water equivalence and upper atmospheric wind direction and speed in the mountains surrounding Gothic, Colorado.” 2010. Web. 19 Sep 2019.

Vancouver:

Chesley-Preston TL. Patterns of natural avalanche activity associated with new snow water equivalance and upper atmospheric wind direction and speed in the mountains surrounding Gothic, Colorado: Patterns of natural avalanche activity associated with new snow water equivalence and upper atmospheric wind direction and speed in the mountains surrounding Gothic, Colorado. [Internet] [Thesis]. Montana State University; 2010. [cited 2019 Sep 19]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/1067.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Chesley-Preston TL. Patterns of natural avalanche activity associated with new snow water equivalance and upper atmospheric wind direction and speed in the mountains surrounding Gothic, Colorado: Patterns of natural avalanche activity associated with new snow water equivalence and upper atmospheric wind direction and speed in the mountains surrounding Gothic, Colorado. [Thesis]. Montana State University; 2010. Available from: https://scholarworks.montana.edu/xmlui/handle/1/1067

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Montana State University

3. Logan, Spencer Carl. Temporal changes in the spatial patterns of weak layer shear strength and stability on uniform slopes.

Degree: College of Letters & Science, 2005, Montana State University

URL: https://scholarworks.montana.edu/xmlui/handle/1/1744

► Avalanche forecasting involves the prediction of spatial and temporal variability of the stability of the snowpack. Greater spatial variability increases the uncertainty of forecasts and… (more)

▼ Avalanche forecasting involves the prediction of spatial and temporal variability of the stability of the snowpack. Greater spatial variability increases the uncertainty of forecasts and reduces the ability of a forecaster to extrapolate snowpack stability reliably. A greater understanding of the spatial patterns of stability, and how they change through time, could improve avalanche forecasting. I examined temporal changes in shear strength and stability of three persistent weak layers at three different sites. Sites were located on uniform slopes to minimize factors that introduce variability or large-scale trends in the snowpack. At each site, shear strength and stability of the same persistent layer were measured in adjacent plots, sampled at intervals of one to eight days apart. Experimental variograms and pit-to-plot ratios provided measures of the spatial variability. Because adjacent plots began with similar conditions, differences between the plots were attributed to temporal change. Shear strength of two buried surface hoar layers increased through time and became more variable. As the layers aged, the rate of strengthening decreased. Stability indices initially increased, then decreased as snowfall increased the slab stress. Changes in the spatial structure were most apparent when the layers were younger and gaining strength most rapidly. As the layers aged, the spatial measures provided less information. Strength of depth hoar increased initially, then decreased as the depth hoar grew and bonds weakened. Spatial correlation increased over time between the first three plots. A strong wind event and warm weather led to considerable change to the snowpack between the third and fourth samples, complicating comparisons. On these three weak layers, shear strength could be reliably extrapolated over a distance of at least 17 m on 86% of the days sampled, provided a sufficient number of tests were conducted to characterize the statistical distribution. The optimal spacing of tests changes as the autocorrelation length of shear strength changes. The number of tests required increases as the overall variability of shear strength increases. This suggests that test spacing is less important on older layers because the autocorrelation length is short, but more tests are required to characterize the slope statistically. Advisors/Committee Members: Chairperson, Graduate Committee: Katherine Hansen. (advisor).

Subjects/Keywords: Avalanches.

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APA (6^th Edition):

Logan, S. C. (2005). Temporal changes in the spatial patterns of weak layer shear strength and stability on uniform slopes. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/1744

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Logan, Spencer Carl. “Temporal changes in the spatial patterns of weak layer shear strength and stability on uniform slopes.” 2005. Thesis, Montana State University. Accessed September 19, 2019. https://scholarworks.montana.edu/xmlui/handle/1/1744.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Logan, Spencer Carl. “Temporal changes in the spatial patterns of weak layer shear strength and stability on uniform slopes.” 2005. Web. 19 Sep 2019.

Vancouver:

Logan SC. Temporal changes in the spatial patterns of weak layer shear strength and stability on uniform slopes. [Internet] [Thesis]. Montana State University; 2005. [cited 2019 Sep 19]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/1744.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Logan SC. Temporal changes in the spatial patterns of weak layer shear strength and stability on uniform slopes. [Thesis]. Montana State University; 2005. Available from: https://scholarworks.montana.edu/xmlui/handle/1/1744

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Montana State University

4. Gleason, John Andrew. Terrain parameters of avalanche starting zones and their effect on avalanche frequency.

Degree: College of Letters & Science, 1996, Montana State University

URL: https://scholarworks.montana.edu/xmlui/handle/1/7490

Subjects/Keywords: Avalanches.

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APA (6^th Edition):

Gleason, J. A. (1996). Terrain parameters of avalanche starting zones and their effect on avalanche frequency. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/7490

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Gleason, John Andrew. “Terrain parameters of avalanche starting zones and their effect on avalanche frequency.” 1996. Thesis, Montana State University. Accessed September 19, 2019. https://scholarworks.montana.edu/xmlui/handle/1/7490.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Gleason, John Andrew. “Terrain parameters of avalanche starting zones and their effect on avalanche frequency.” 1996. Web. 19 Sep 2019.

Vancouver:

Gleason JA. Terrain parameters of avalanche starting zones and their effect on avalanche frequency. [Internet] [Thesis]. Montana State University; 1996. [cited 2019 Sep 19]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/7490.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Gleason JA. Terrain parameters of avalanche starting zones and their effect on avalanche frequency. [Thesis]. Montana State University; 1996. Available from: https://scholarworks.montana.edu/xmlui/handle/1/7490

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Montana State University

5. Trautman, Simon August. Wet loose snow avalanching in southwestern Montana.

Degree: College of Letters & Science, 2007, Montana State University

URL: https://scholarworks.montana.edu/xmlui/handle/1/2438

► Results are consistent with prior research and clearly show that temperature alone is not a good indicator. The third relates wet loose snow avalanching to… (more)

Subjects/Keywords: Avalanches.; Avalanches Forecasting.

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APA (6^th Edition):

Trautman, S. A. (2007). Wet loose snow avalanching in southwestern Montana. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/2438

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Trautman, Simon August. “Wet loose snow avalanching in southwestern Montana.” 2007. Thesis, Montana State University. Accessed September 19, 2019. https://scholarworks.montana.edu/xmlui/handle/1/2438.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Trautman, Simon August. “Wet loose snow avalanching in southwestern Montana.” 2007. Web. 19 Sep 2019.

Vancouver:

Trautman SA. Wet loose snow avalanching in southwestern Montana. [Internet] [Thesis]. Montana State University; 2007. [cited 2019 Sep 19]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/2438.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Trautman SA. Wet loose snow avalanching in southwestern Montana. [Thesis]. Montana State University; 2007. Available from: https://scholarworks.montana.edu/xmlui/handle/1/2438

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Montana State University

6. Romig, Jeannette M. March wet avalanche prediction at Bridger Bowl ski area, Montana.

Degree: College of Letters & Science, 2004, Montana State University

URL: https://scholarworks.montana.edu/xmlui/handle/1/2151

► Wet avalanches are a safety concern for all ski areas because they are difficult to control artificially and the shift from safe to dangerous wet… (more)

▼ Wet avalanches are a safety concern for all ski areas because they are difficult to control artificially and the shift from safe to dangerous wet snow conditions can happen very quickly. Forecasting for wet avalanche conditions in intermountain ski areas, such as Bridger Bowl, Montana, can be especially difficult because intermountain snow climates can exhibit wet avalanche characteristics of either maritime or continental snow climates. Various statistical models have been developed for avalanche prediction; however, most are tailored specifically for dry avalanche forecasting. Archived meteorological, snowpack and avalanche data for the month of March from 1968 to 2001 (1996 data unavailable) were used to develop 68 possible predictor variables related to temperature, snowpack settlement, and precipitation characteristics. The original Bridger Bowl dataset was divided into a ♯new snowα and an ♯old snowα dataset. A ♯new snowα day has newly fallen snow that is less than 48 hours old; an ♯old snowα day has newly fallen snow that is more than 48 hours old. The two datasets were used to determine whether the factors that influence ♯old snowα and ♯new snowα wet avalanche occurrence differ. Hypotheses were developed and tested to determine which ♯old snowα and ♯new snowα variables behaved significantly different on days with wet avalanches compared to days with no wet avalanches. The 33 ♯old snowα significant variables and the 22 ♯new snowα significant variables were analyzed with binomial logistic regression to produce one prediction model for ♯old snowα wet avalanche conditions and another prediction model for ♯new snowα wet avalanche conditions. The ♯old snowα model uses the prediction day minimum temperature and the two day change in total snow depth as predictor variables. This model has a 75% success rate for calculating accurate wet avalanche probabilities for ♯old snowα days. The ♯new snowα model uses the prediction day minimum temperature as well as the three day cumulative new snow water equivalent as predictor variables. This model has a 72% success rate for calculating accurate wet avalanche probabilities for ♯new snowα days. Advisors/Committee Members: Chairperson, Graduate Committee: Stephan G. Custer. (advisor).

Subjects/Keywords: Avalanches Forecasting.; Avalanches.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Romig, J. M. (2004). March wet avalanche prediction at Bridger Bowl ski area, Montana. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/2151

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Romig, Jeannette M. “March wet avalanche prediction at Bridger Bowl ski area, Montana.” 2004. Thesis, Montana State University. Accessed September 19, 2019. https://scholarworks.montana.edu/xmlui/handle/1/2151.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Romig, Jeannette M. “March wet avalanche prediction at Bridger Bowl ski area, Montana.” 2004. Web. 19 Sep 2019.

Vancouver:

Romig JM. March wet avalanche prediction at Bridger Bowl ski area, Montana. [Internet] [Thesis]. Montana State University; 2004. [cited 2019 Sep 19]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/2151.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Romig JM. March wet avalanche prediction at Bridger Bowl ski area, Montana. [Thesis]. Montana State University; 2004. Available from: https://scholarworks.montana.edu/xmlui/handle/1/2151

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Université du Québec à Montréal

7. Martin, Jean-Philippe. Reconstitution dendrochronologique des années de forte activité avalancheuse dans la Chaîne présidentielle (New Hampshire, États-Unis) : scénarios météorologiques et climatiques.

Degree: 2016, Université du Québec à Montréal

URL: http://archipel.uqam.ca/8820/1/D3116.pdf

► Les avalanches de neige constituent un risque naturel important dans les chaînes de montagnes à l'échelle globale, mais également dans le Nord-Est nord-américain. La Chaîne… (more)

▼ Les avalanches de neige constituent un risque naturel important dans les chaînes de montagnes à l'échelle globale, mais également dans le Nord-Est nord-américain. La Chaîne Présidentielle (New Hampshire, États-Unis) constitue l'une des plus vastes superficies alpines au sud du Labrador. À cet effet, elle représente un lieu important pour la pratique des sports de montagne sur les versants raides. Bien qu'un programme de prévision des avalanches est instauré depuis 1959, aucune archive historique n'existe. La dendrochronologie est reconnue comme une technique valide pour reconstituer l'occurrence passée de processus géomorphologiques divers. Cette thèse vise à documenter par dendrochronologie l'historique des avalanches de forte intensité dans la Chaîne Présidentielle et à mieux comprendre comment les facteurs météorologiques et climatiques influencent cette dynamique. Dans un premier temps, il importe de se questionner sur la singularité des milieux alpins du Nord-Est nord-américain. Une méta-analyse de la littérature scientifique a démontré que l'occurrence de cet environnement à si basse altitude dans la région d'étude résulte des interactions complexes entre la géosphère, l'atmosphère et la biosphère. Bien que la colonisation végétale ait suivi le même gradient sud-nord que le retrait de l'inlandsis Laurentien, trois facteurs contribuent à la mise en place, au maintien et à la diversité de ces environnements : l'élasticité du temps paraglaciaire, les effets de synergie entre les facteurs locaux tels que les dynamiques écologiques et les forçages climatiques, ainsi que la sensibilité et la résilience des milieux alpins. Dans un deuxième temps, afin de contribuer à l'avancement des méthodes en dendrogéomorphologie, la possibilité de discriminer le signal attribué aux avalanches de neige d'autres perturbations climatiques, écologiques ou géomorphologiques a été étudiée. Ces cas d'études ont permis de démontrer que la surcharge nivale peut entraîner des séquences de bois de réaction suffisamment importantes pour être considérées comme des perturbations majeures à l'instar des avalanches de neige. D'autre part, la réponse dendrochronologique des châblis et de l'activité torrentielle présente des patrons spatiaux distincts des avalanches de neige, ce qui permet de les distinguer même si leur occurrence peut être synchrone à l'échelle annuelle. Ensuite, une reconstitution dendrochronologique de l'activité avalancheuse de sept couloirs a permis d'identifier des variables météorologiques reliées à l'occurrence d'avalanches de neige de forte intensité grâce aux arbres de classification. Cet algorithme s'est avéré supérieur aux régressions logistiques par sa capacité à prédire correctement les années avalancheuses. Leur architecture a permis de dégager des scénarios expliquant l'activité avalancheuse, soit : 1) une fréquence importance de tempêtes de neige; 2) un enneigement supérieur à la moyenne; 3) des températures favorisant la formation de couches fragiles et 4) la présence de vents violents. Finalement, à partir de ces…

Subjects/Keywords: Avalanches – Presidential Range – Histoire; Dendrochronologie; Avalanches – Facteurs climatiques – Presidential Range – Méthodes statistiques; Avalanches – Lutte contre

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Martin, J. (2016). Reconstitution dendrochronologique des années de forte activité avalancheuse dans la Chaîne présidentielle (New Hampshire, États-Unis) : scénarios météorologiques et climatiques. (Thesis). Université du Québec à Montréal. Retrieved from http://archipel.uqam.ca/8820/1/D3116.pdf

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Martin, Jean-Philippe. “Reconstitution dendrochronologique des années de forte activité avalancheuse dans la Chaîne présidentielle (New Hampshire, États-Unis) : scénarios météorologiques et climatiques.” 2016. Thesis, Université du Québec à Montréal. Accessed September 19, 2019. http://archipel.uqam.ca/8820/1/D3116.pdf.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Martin, Jean-Philippe. “Reconstitution dendrochronologique des années de forte activité avalancheuse dans la Chaîne présidentielle (New Hampshire, États-Unis) : scénarios météorologiques et climatiques.” 2016. Web. 19 Sep 2019.

Vancouver:

Martin J. Reconstitution dendrochronologique des années de forte activité avalancheuse dans la Chaîne présidentielle (New Hampshire, États-Unis) : scénarios météorologiques et climatiques. [Internet] [Thesis]. Université du Québec à Montréal; 2016. [cited 2019 Sep 19]. Available from: http://archipel.uqam.ca/8820/1/D3116.pdf.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Martin J. Reconstitution dendrochronologique des années de forte activité avalancheuse dans la Chaîne présidentielle (New Hampshire, États-Unis) : scénarios météorologiques et climatiques. [Thesis]. Université du Québec à Montréal; 2016. Available from: http://archipel.uqam.ca/8820/1/D3116.pdf

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Hong Kong University of Science and Technology

8. Chan, Wai Yuen. Probabilistic debris mobility modeling.

Degree: 2009, Hong Kong University of Science and Technology

URL: https://doi.org/10.14711/thesis-b1070898 ; http://repository.ust.hk/ir/bitstream/1783.1-6309/1/th_redirect.html

► Debris mobility modeling is important and challenging in Hong Kong. Under the concept of equivalent fluid, which is aimed to reproduce the motion experienced by… (more)

Subjects/Keywords: Debris avalanches – Forecasting – Mathematical models

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APA (6^th Edition):

Chan, W. Y. (2009). Probabilistic debris mobility modeling. (Thesis). Hong Kong University of Science and Technology. Retrieved from https://doi.org/10.14711/thesis-b1070898 ; http://repository.ust.hk/ir/bitstream/1783.1-6309/1/th_redirect.html

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Chan, Wai Yuen. “Probabilistic debris mobility modeling.” 2009. Thesis, Hong Kong University of Science and Technology. Accessed September 19, 2019. https://doi.org/10.14711/thesis-b1070898 ; http://repository.ust.hk/ir/bitstream/1783.1-6309/1/th_redirect.html.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Chan, Wai Yuen. “Probabilistic debris mobility modeling.” 2009. Web. 19 Sep 2019.

Vancouver:

Chan WY. Probabilistic debris mobility modeling. [Internet] [Thesis]. Hong Kong University of Science and Technology; 2009. [cited 2019 Sep 19]. Available from: https://doi.org/10.14711/thesis-b1070898 ; http://repository.ust.hk/ir/bitstream/1783.1-6309/1/th_redirect.html.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Chan WY. Probabilistic debris mobility modeling. [Thesis]. Hong Kong University of Science and Technology; 2009. Available from: https://doi.org/10.14711/thesis-b1070898 ; http://repository.ust.hk/ir/bitstream/1783.1-6309/1/th_redirect.html

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Montana State University

9. Peitzsch, Erich Hans. Water movement in a stratified and inclined snowpack : implications for wet slab avalanches.

Degree: College of Letters & Science, 2009, Montana State University

URL: https://scholarworks.montana.edu/xmlui/handle/1/2034

► Wet snow avalanches are dangerous and can be particularly difficult to predict. The rate of change from safe snow conditions to dangerous snow conditions occurs… (more)

▼ Wet snow avalanches are dangerous and can be particularly difficult to predict. The rate of change from safe snow conditions to dangerous snow conditions occurs rapidly in a wet snowpack, often in response to water production and movement. This research focused on the relationship between snow stratigraphy and water movement in an inclined snowpack. Concentrating on transitions that impede water and flow finger formation within the snowpack, dye tracer was mixed with water and applied to a stratified snowpack to observe and measure the movement of water in various snow grain types, sizes, densities, and temperatures. There were two types of layer transitions that impeded water. Water was impeded at capillary boundaries caused by fine grains over coarse grains. It was also impeded at hydraulic conductivity boundaries, such as ice layers. In layer transitions that impeded water, the grain size of the layer above was significantly smaller than the layer below. The layer above a transition that impeded water was also significantly less dense than the layer below the transition. A qualitative analysis of grain type showed that there was no relationship between grain types in the layer above or below a transition and whether they will or will not impede water. A SnowMicroPen (SMP) was used to measure changes in structural element length to identify capillary boundaries. Results from SMP measurements indicate that microstructural analysis of the snowpack aids in characterizing capillary boundaries that impede water flow. The step change, rate of change, and percent increase were significantly larger in capillary boundaries than transitions that did not impede water for the entire dataset from all 8 sessions. When all transitions were ranked according to absolute change for each profile, capillary boundaries consistently ranked in the top two of all transitions evident within each SMP profile. The amount of water needed to produce flow fingers was highly variable. There was no significant relationship between the amount of water necessary to form flow fingers and snow density, snow grain size, snow temperature, or grain type. Layer transitions that impeded vertical water movement and flow finger formation may both play a large role in wet slab avalanche formation. Advisors/Committee Members: Chairperson, Graduate Committee: Katherine J. Hansen. (advisor).

Subjects/Keywords: Avalanches.; Snow Thermal properties.

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APA (6^th Edition):

Peitzsch, E. H. (2009). Water movement in a stratified and inclined snowpack : implications for wet slab avalanches. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/2034

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Peitzsch, Erich Hans. “Water movement in a stratified and inclined snowpack : implications for wet slab avalanches.” 2009. Thesis, Montana State University. Accessed September 19, 2019. https://scholarworks.montana.edu/xmlui/handle/1/2034.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Peitzsch, Erich Hans. “Water movement in a stratified and inclined snowpack : implications for wet slab avalanches.” 2009. Web. 19 Sep 2019.

Vancouver:

Peitzsch EH. Water movement in a stratified and inclined snowpack : implications for wet slab avalanches. [Internet] [Thesis]. Montana State University; 2009. [cited 2019 Sep 19]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/2034.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Peitzsch EH. Water movement in a stratified and inclined snowpack : implications for wet slab avalanches. [Thesis]. Montana State University; 2009. Available from: https://scholarworks.montana.edu/xmlui/handle/1/2034

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Montana State University

10. Guy, Zachary Mark. The influence of terrain parameters on the spatial variability of potential avalanche trigger locations in complex avalanche terrain.

Degree: College of Letters & Science, 2011, Montana State University

URL: https://scholarworks.montana.edu/xmlui/handle/1/1400

► More winter recreationists are venturing into steep avalanche chutes and "extreme" terrain each year, and avalanche fatalities are increasing. The slope-scale spatial variability of weak… (more)

▼ More winter recreationists are venturing into steep avalanche chutes and "extreme" terrain each year, and avalanche fatalities are increasing. The slope-scale spatial variability of weak layers and slabs and how it relates to this complex terrain is of critical importance but poorly understood. In this study, I use terrain parameters to model potential trigger locations (PTLs) of slab avalanches, which are defined based on slab thicknesses and presence of weak layers. In a sample couloirs and chutes in Montana and Wyoming, field teams tracked and mapped persistent weak layers and slabs with probe sampling. Terrain parameters derived from a one meter DEM were used to explore the relationships between PTLs and terrain. Exploratory analysis, multi-model classification trees, and logistic regression models support strong relationships between terrain and PTLs. Modeling of PTLs was highly successful for individual couloirs, with terrain-based model success rates frequently exceeding 70% for depth hoar PTLs and 85% for near-surface weak layers. However, models varied widely from couloir to couloir, with generally poor cross-validation results between couloirs, suggesting that the relationships between terrain and PTLs in each couloir are unique and highly complex. For these 21 couloirs in steep alpine terrain, parameters relating to wind deposition and scouring have the strongest association with PTLs.. Parameters with the greatest ability to discriminate PTLs are distance from the edge of a couloir, relative elevation, degree of wind exposure, and degree of terrain exposure. The influences of these and other terrain parameters vary, depending on broader-scale terrain characteristics, prior weather patterns, and seasonal trends. Practical implications from this study are numerous. With an understanding of the broader scale influences and physical processes involved, we can use terrain to optimize stability test locations, explosive placements, or route selection. The unique nature of each couloir means that simple rules relating terrain to PTLs will not apply, although couloirs in the same cirque generally share similarities. This work increases our understanding of how each parameter relates to the physical processes causing PTLs and how these relationships can vary. This information will help to improve practical decision-making ability as well as future modeling efforts. Advisors/Committee Members: Chairperson, Graduate Committee: Karl W. Birkeland. (advisor).

Subjects/Keywords: Snow.; Avalanches.; Depth hoar.

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APA (6^th Edition):

Guy, Z. M. (2011). The influence of terrain parameters on the spatial variability of potential avalanche trigger locations in complex avalanche terrain. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/1400

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Guy, Zachary Mark. “The influence of terrain parameters on the spatial variability of potential avalanche trigger locations in complex avalanche terrain.” 2011. Thesis, Montana State University. Accessed September 19, 2019. https://scholarworks.montana.edu/xmlui/handle/1/1400.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Guy, Zachary Mark. “The influence of terrain parameters on the spatial variability of potential avalanche trigger locations in complex avalanche terrain.” 2011. Web. 19 Sep 2019.

Vancouver:

Guy ZM. The influence of terrain parameters on the spatial variability of potential avalanche trigger locations in complex avalanche terrain. [Internet] [Thesis]. Montana State University; 2011. [cited 2019 Sep 19]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/1400.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Guy ZM. The influence of terrain parameters on the spatial variability of potential avalanche trigger locations in complex avalanche terrain. [Thesis]. Montana State University; 2011. Available from: https://scholarworks.montana.edu/xmlui/handle/1/1400

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Montana State University

11. Hancock, Holt John. Snow drift and avalanche activity in a high arctic maritime snow climate.

Degree: College of Letters & Science, 2016, Montana State University

URL: https://scholarworks.montana.edu/xmlui/handle/1/14624

► Snow drift endangers human life and infrastructure in alpine and arctic environments by contributing to snow avalanche formation in steep terrain and impacting transportation through… (more)

▼ Snow drift endangers human life and infrastructure in alpine and arctic environments by contributing to snow avalanche formation in steep terrain and impacting transportation through reduced visibilities and drift deposition on roadways. Understanding the local and synoptic scale meteorological conditions just prior to and during hazardous snow drift conditions is a crucial element in forecasting for – and mitigating the hazards associated with – snow drift processes. This is especially true in Svalbard, a High Arctic Norwegian archipelago, where snow drift processes have been linked to avalanche activity and hazardous travel conditions in the region's unique, direct-action maritime snow climate. This study uses a record of road closures due to drifting snow on a mountain road to further investigate Svalbard's snow climate and avalanche regime by characterizing meteorological conditions leading to regional snow drift events and exploring the relationship between these periods of snow drift and regional avalanche activity. A nine-year record of road closures is coupled with local meteorological observations and NCEP/NCAR synoptic composite maps to characterize the local and synoptic weather conditions leading to and occurring during periods of snow drift near Longyearbyen, Svalbard's primary settlement. This record of snow drift events is then compared with regional avalanche observations using a case study approach to illustrate the relationship between snow drift and avalanche activity in Svalbard. Results show snow drift events result from five distinct synoptic circulation types and are characterized by increased wind speeds, higher precipitation totals, and elevated air temperatures relative to average winter conditions. Four case studies qualitatively illustrate the interactions between local and synoptic weather patterns, snow drift processes, and regional avalanche activity. In addition to the suggested mitigation strategies provided, these results will help advance avalanche forecasting efforts throughout the region. Advisors/Committee Members: Chairperson, Graduate Committee: Jordy Hendrikx (advisor).

Subjects/Keywords: Snow.; Winds.; Avalanches.; Climatology.

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APA (6^th Edition):

Hancock, H. J. (2016). Snow drift and avalanche activity in a high arctic maritime snow climate. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/14624

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Hancock, Holt John. “Snow drift and avalanche activity in a high arctic maritime snow climate.” 2016. Thesis, Montana State University. Accessed September 19, 2019. https://scholarworks.montana.edu/xmlui/handle/1/14624.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Hancock, Holt John. “Snow drift and avalanche activity in a high arctic maritime snow climate.” 2016. Web. 19 Sep 2019.

Vancouver:

Hancock HJ. Snow drift and avalanche activity in a high arctic maritime snow climate. [Internet] [Thesis]. Montana State University; 2016. [cited 2019 Sep 19]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/14624.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Hancock HJ. Snow drift and avalanche activity in a high arctic maritime snow climate. [Thesis]. Montana State University; 2016. Available from: https://scholarworks.montana.edu/xmlui/handle/1/14624

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Montana State University

12. Rose, Charles Cleland. Seismic moment, stress drop, strain energy, dislocation radius, and location of seismic acoustical emissions associated with a high alpine snowpack at Berthoud Pass, Colorado.

Degree: College of Letters & Science, 1981, Montana State University

URL: https://scholarworks.montana.edu/xmlui/handle/1/3672

Subjects/Keywords: Avalanches.; Snow.

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APA (6^th Edition):

Rose, C. C. (1981). Seismic moment, stress drop, strain energy, dislocation radius, and location of seismic acoustical emissions associated with a high alpine snowpack at Berthoud Pass, Colorado. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/3672

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Rose, Charles Cleland. “Seismic moment, stress drop, strain energy, dislocation radius, and location of seismic acoustical emissions associated with a high alpine snowpack at Berthoud Pass, Colorado.” 1981. Thesis, Montana State University. Accessed September 19, 2019. https://scholarworks.montana.edu/xmlui/handle/1/3672.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Rose, Charles Cleland. “Seismic moment, stress drop, strain energy, dislocation radius, and location of seismic acoustical emissions associated with a high alpine snowpack at Berthoud Pass, Colorado.” 1981. Web. 19 Sep 2019.

Vancouver:

Rose CC. Seismic moment, stress drop, strain energy, dislocation radius, and location of seismic acoustical emissions associated with a high alpine snowpack at Berthoud Pass, Colorado. [Internet] [Thesis]. Montana State University; 1981. [cited 2019 Sep 19]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/3672.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Rose CC. Seismic moment, stress drop, strain energy, dislocation radius, and location of seismic acoustical emissions associated with a high alpine snowpack at Berthoud Pass, Colorado. [Thesis]. Montana State University; 1981. Available from: https://scholarworks.montana.edu/xmlui/handle/1/3672

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Montana State University

13. Lang, Renee M. Studies on surface hoar : formation and physical properties.

Degree: College of Engineering, 1985, Montana State University

URL: https://scholarworks.montana.edu/xmlui/handle/1/3999

Subjects/Keywords: Frost.; Avalanches.

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APA (6^th Edition):

Lang, R. M. (1985). Studies on surface hoar : formation and physical properties. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/3999

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Lang, Renee M. “Studies on surface hoar : formation and physical properties.” 1985. Thesis, Montana State University. Accessed September 19, 2019. https://scholarworks.montana.edu/xmlui/handle/1/3999.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Lang, Renee M. “Studies on surface hoar : formation and physical properties.” 1985. Web. 19 Sep 2019.

Vancouver:

Lang RM. Studies on surface hoar : formation and physical properties. [Internet] [Thesis]. Montana State University; 1985. [cited 2019 Sep 19]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/3999.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Lang RM. Studies on surface hoar : formation and physical properties. [Thesis]. Montana State University; 1985. Available from: https://scholarworks.montana.edu/xmlui/handle/1/3999

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Montana State University

14. Landry, Christopher Cameron. Spatial variations in snow stability on uniform slopes : implications for extrapolation to surrounding terrain.

Degree: College of Letters & Science, 2002, Montana State University

URL: https://scholarworks.montana.edu/xmlui/handle/1/8264

Subjects/Keywords: Avalanches.; Extrapolation.

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APA (6^th Edition):

Landry, C. C. (2002). Spatial variations in snow stability on uniform slopes : implications for extrapolation to surrounding terrain. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/8264

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Landry, Christopher Cameron. “Spatial variations in snow stability on uniform slopes : implications for extrapolation to surrounding terrain.” 2002. Thesis, Montana State University. Accessed September 19, 2019. https://scholarworks.montana.edu/xmlui/handle/1/8264.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Landry, Christopher Cameron. “Spatial variations in snow stability on uniform slopes : implications for extrapolation to surrounding terrain.” 2002. Web. 19 Sep 2019.

Vancouver:

Landry CC. Spatial variations in snow stability on uniform slopes : implications for extrapolation to surrounding terrain. [Internet] [Thesis]. Montana State University; 2002. [cited 2019 Sep 19]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/8264.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Landry CC. Spatial variations in snow stability on uniform slopes : implications for extrapolation to surrounding terrain. [Thesis]. Montana State University; 2002. Available from: https://scholarworks.montana.edu/xmlui/handle/1/8264

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Montana State University

15. Marienthal, Alex Grayson. Meteorological metrics associated with deep slab avalanches on persistent weak layers.

Degree: College of Letters & Science, 2014, Montana State University

URL: https://scholarworks.montana.edu/xmlui/handle/1/8786

► Snow avalanches are a potentially fatal and highly destructive natural hazard. Snow slab avalanches occur in steep alpine terrain due to an unstable layered snowpack.… (more)

▼ Snow avalanches are a potentially fatal and highly destructive natural hazard. Snow slab avalanches occur in steep alpine terrain due to an unstable layered snowpack. When a consolidated layer of snow forms a slab above a weak layer of snow the slab may collapse and slide downhill due to gravitational and applied forces (e.g., the weight of a skier, explosive, or new snowfall). Persistent weak layers form in the snowpack due to strong vapor pressure gradients, and they can last for weeks to months as a slab builds above them. Avalanches on persistent weak layers become less frequent, yet are typically larger and more destructive the longer and deeper the layer is buried. Deep slab avalanches on persistent weak layers pose a difficult forecasting problem due to their low likelihood of occurrence and potentially high consequences. This thesis aims to identify meteorological metrics that are associated with deep slabs on persistent weak layers. We used univariate analysis, classification trees, and random forests to explore relationships between seasons with deep slabs and summaries of meteorological metrics over the beginning of the season during weak layer formation. We also looked at the relationship between days with these avalanches and summaries of meteorological metrics over the days prior to them. In addition, we reviewed a case study of a season that had multiple deep slabs on a persistent weak layer and a historic wet slab avalanche cycle on the same layer, at Bridger Bowl ski area. Seasons with deep slabs typically had relatively low precipitation throughout the early part of the season (i.e., November - January), and a snowpack in the beginning of the season that was sufficiently deep, but shallow enough for a weak layer to develop. Our results also showed warmer twenty-four hour temperatures and more precipitation over seven day prior to days with dry deep slabs, and extended periods of above freezing temperatures were seen prior to days with deep wet slabs. These results are in line with previous research and are suggestive of meteorological summaries that may be useful to forecast deep slab avalanches on persistent weak layers. Advisors/Committee Members: Chairperson, Graduate Committee: Jordy Hendrikx (advisor).

Subjects/Keywords: Avalanches Forecasting.; Depth hoar.; Weather.

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APA (6^th Edition):

Marienthal, A. G. (2014). Meteorological metrics associated with deep slab avalanches on persistent weak layers. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/8786

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Marienthal, Alex Grayson. “Meteorological metrics associated with deep slab avalanches on persistent weak layers.” 2014. Thesis, Montana State University. Accessed September 19, 2019. https://scholarworks.montana.edu/xmlui/handle/1/8786.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Marienthal, Alex Grayson. “Meteorological metrics associated with deep slab avalanches on persistent weak layers.” 2014. Web. 19 Sep 2019.

Vancouver:

Marienthal AG. Meteorological metrics associated with deep slab avalanches on persistent weak layers. [Internet] [Thesis]. Montana State University; 2014. [cited 2019 Sep 19]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/8786.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Marienthal AG. Meteorological metrics associated with deep slab avalanches on persistent weak layers. [Thesis]. Montana State University; 2014. Available from: https://scholarworks.montana.edu/xmlui/handle/1/8786

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

16. Costa, Ariadne de Andrade. Quasi-criticalidade auto-organizada em avalanches neuronais.

Degree: Mestrado, Física Aplicada à Medicina e Biologia, 2011, University of São Paulo

URL: http://www.teses.usp.br/teses/disponiveis/59/59135/tde-17112011-204509/ ;

►

Experimentos têm revelado que redes de neurônios, tanto in vitro como in vivo, mantêm atividade descrita por avalanches e se organizam em um estado crítico… (more)

Subjects/Keywords: avalanches neuronais; criticalidade auto-organizada; neuronal avalanches; self-organized criticality

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APA (6^th Edition):

Costa, A. d. A. (2011). Quasi-criticalidade auto-organizada em avalanches neuronais. (Masters Thesis). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/59/59135/tde-17112011-204509/ ;

Chicago Manual of Style (16^th Edition):

Costa, Ariadne de Andrade. “Quasi-criticalidade auto-organizada em avalanches neuronais.” 2011. Masters Thesis, University of São Paulo. Accessed September 19, 2019. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-17112011-204509/ ;.

MLA Handbook (7^th Edition):

Costa, Ariadne de Andrade. “Quasi-criticalidade auto-organizada em avalanches neuronais.” 2011. Web. 19 Sep 2019.

Vancouver:

Costa AdA. Quasi-criticalidade auto-organizada em avalanches neuronais. [Internet] [Masters thesis]. University of São Paulo; 2011. [cited 2019 Sep 19]. Available from: http://www.teses.usp.br/teses/disponiveis/59/59135/tde-17112011-204509/ ;.

Council of Science Editors:

Costa AdA. Quasi-criticalidade auto-organizada em avalanches neuronais. [Masters Thesis]. University of São Paulo; 2011. Available from: http://www.teses.usp.br/teses/disponiveis/59/59135/tde-17112011-204509/ ;

University of Hong Kong

17. 趙汝豪; Chiu, Yu-ho. Design of barriers against recurrent debris flows.

Degree: MS, 2003, University of Hong Kong

URL: Chiu, Y. [趙汝豪]. (2003). Design of barriers against recurrent debris flows. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. Retrieved from http://dx.doi.org/10.5353/th_b3043166 ; http://dx.doi.org/10.5353/th_b3043166 ; http://hdl.handle.net/10722/31620

published_or_final_version

abstract

toc

Applied Geosciences

Master

Master of Science

Subjects/Keywords: Debris avalanches - Control.; Debris avalanches.

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APA (6^th Edition):

趙汝豪; Chiu, Y. (2003). Design of barriers against recurrent debris flows. (Masters Thesis). University of Hong Kong. Retrieved from Chiu, Y. [趙汝豪]. (2003). Design of barriers against recurrent debris flows. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. Retrieved from http://dx.doi.org/10.5353/th_b3043166 ; http://dx.doi.org/10.5353/th_b3043166 ; http://hdl.handle.net/10722/31620

Chicago Manual of Style (16^th Edition):

趙汝豪; Chiu, Yu-ho. “Design of barriers against recurrent debris flows.” 2003. Masters Thesis, University of Hong Kong. Accessed September 19, 2019. Chiu, Y. [趙汝豪]. (2003). Design of barriers against recurrent debris flows. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. Retrieved from http://dx.doi.org/10.5353/th_b3043166 ; http://dx.doi.org/10.5353/th_b3043166 ; http://hdl.handle.net/10722/31620.

MLA Handbook (7^th Edition):

趙汝豪; Chiu, Yu-ho. “Design of barriers against recurrent debris flows.” 2003. Web. 19 Sep 2019.

Vancouver:

趙汝豪; Chiu Y. Design of barriers against recurrent debris flows. [Internet] [Masters thesis]. University of Hong Kong; 2003. [cited 2019 Sep 19]. Available from: Chiu, Y. [趙汝豪]. (2003). Design of barriers against recurrent debris flows. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. Retrieved from http://dx.doi.org/10.5353/th_b3043166 ; http://dx.doi.org/10.5353/th_b3043166 ; http://hdl.handle.net/10722/31620.

Council of Science Editors:

趙汝豪; Chiu Y. Design of barriers against recurrent debris flows. [Masters Thesis]. University of Hong Kong; 2003. Available from: Chiu, Y. [趙汝豪]. (2003). Design of barriers against recurrent debris flows. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. Retrieved from http://dx.doi.org/10.5353/th_b3043166 ; http://dx.doi.org/10.5353/th_b3043166 ; http://hdl.handle.net/10722/31620

Oregon State University

18. May, Christine L. Debris flow characteristics associated with forest practices in the central Oregon Coast Range.

Degree: MS, Forest Engineering, 1998, Oregon State University

URL: http://hdl.handle.net/1957/9572

► Debris flows in the Pacific Northwest play a major role in routing wood and sediment stored on hillslopes and in first- through third-order channels to… (more)

▼ Debris flows in the Pacific Northwest play a major role in routing wood and sediment stored on hillslopes and in first- through third-order channels to higher order channels and valley floors. Forest practices on steep, unstable slopes and removal of riparian trees along low-order streams can affect the frequency, magnitude, and composition of debris flows. The quantity and quality of debris flow deposits provides sediment and wood fundamental to the development of the receiving channel. Field surveys document characteristics of the initiation site, runout zone, and deposit of 53 debris flows in the Siuslaw Basin of the central Oregon Coast Range, during the winter of 1996. Landslides that initiated debris flows in clearcuts had a higher frequency, larger average volume, and runout zones that affected a greater length of stream channel than landslides from forested slopes. This difference resulted in an increase in the total volume of sediment mobilized by the debris flow, and a greater proportion of this sediment came from hillslope sources. Debris flows initiated at roads had an order of magnitude greater volume of sediment compared to non-road-related failures. Debris flows of equivalent size that traveled through a forested channel delivered only a slightly greater volume of large wood, than those through clearcuts. Size-class distributions of wood in the deposit and trees on the hillslope were not well correlated. The average diameter of wood in the deposit was greater than the diameter of trees currently present on the surrounding hillslopes. This difference reflects the legacy of large woody debris stored in low-order channels and valley floors. Large trees along the edge of the runout zone is also an important component in the recovery of these low-order channels, which were transformed into a bedrock state. Large trees along the edges of forested slopes are already supplying wood to these channels, and were the only mechanism observed for trapping large volumes of sediment. This mechanism for retaining sediment in high gradient, low-roughness channels is not available in clearcuts, which now contain the greatest proportion of bedrock channels. Forest practices, by altering the frequency, magnitude, and composition of the debris flow, may alter the long-term potential for developing complex channel morphology and high-quality aquatic habitat. Advisors/Committee Members: Skaugset III, Arne E. (advisor).

Subjects/Keywords: Debris avalanches – Oregon

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APA (6^th Edition):

May, C. L. (1998). Debris flow characteristics associated with forest practices in the central Oregon Coast Range. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/9572

Chicago Manual of Style (16^th Edition):

May, Christine L. “Debris flow characteristics associated with forest practices in the central Oregon Coast Range.” 1998. Masters Thesis, Oregon State University. Accessed September 19, 2019. http://hdl.handle.net/1957/9572.

MLA Handbook (7^th Edition):

May, Christine L. “Debris flow characteristics associated with forest practices in the central Oregon Coast Range.” 1998. Web. 19 Sep 2019.

Vancouver:

May CL. Debris flow characteristics associated with forest practices in the central Oregon Coast Range. [Internet] [Masters thesis]. Oregon State University; 1998. [cited 2019 Sep 19]. Available from: http://hdl.handle.net/1957/9572.

Council of Science Editors:

May CL. Debris flow characteristics associated with forest practices in the central Oregon Coast Range. [Masters Thesis]. Oregon State University; 1998. Available from: http://hdl.handle.net/1957/9572

Oregon State University

19. Parker, Lauren E. Meteorological conditions associated with rain-related periglacial debris flows on Mount Hood, Oregon and Mount Rainier, Washington.

Degree: MS, Geography, 2009, Oregon State University

URL: http://hdl.handle.net/1957/11967

► In November of 2006 an intense rainstorm of tropical origin, known colloquially as the "Pineapple Express," inundated the Pacific Northwest region of the United States,… (more)

▼ In November of 2006 an intense rainstorm of tropical origin, known colloquially as the "Pineapple Express," inundated the Pacific Northwest region of the United States, initiating numerous periglacial debris flows on several of the stratovolcanoes in the Cascade Range of Oregon and Washington. These debris flows rapidly aggrade channels, deposit thick sediments in their path, and severely damage infrastructure. Consequently, this work seeks to understand the potential meteorological triggering mechanisms of these flow events. Here we focus on Mount Hood, Oregon and Mount Rainier, Washington in the investigation of the meteorological conditions associated with rain-related periglacial debris flow events and the variability of these conditions over time. The objectives of this research are to assess the correlation between "Pineapple Express" and "Atmospheric River" events and rain-related debris flows, and to explore the meteorological conditions associated with debris flow events based on 5 parameters: storm track based on geostrophic flow patterns, temperature, precipitation and orographic enhancement, integrated atmospheric moisture transport, and antecedent snow water equivalent (SWE). Dates for the debris flow events for each mountain were linked with corresponding Pineapple Express circulation and Atmospheric River events. Analysis from this work suggests that there is not a strong correlation between the occurrence of debris flows and the occurrence of Pineapple Express or Atmospheric River events as they are presently defined in the literature. NCEP/NCAR reanalysis data were used to determine geostrophic flow from 500h-Pa heights. Radiosonde data from Salem, Oregon and Quillayute, Washington were used to examine freezing altitudes. Precipitation data from Government Camp and Paradise meteorological stations were used to determine total rainfall amounts for rain events, and these data were compared with precipitation data from coupled lower elevation sites (Three Lynx and Longmire, respectively) to determine orographic enhancement values for each event. Reanalysis data were again used to determine the strength and direction of atmospheric moisture transport. Snowpack Telemetry (SNOTEL) data were used to examine the antecedent snowpack conditions for each debris flow event. Debris flows on both Mount Hood and Mount Rainier were found to be associated with both meridional and zonal flow regimes, variable precipitation, and unimpressive orographic enhancement values. However, the debris flow events virtually all experienced significantly high freezing altitudes and little or negligible antecedent SWE. Further, nearly all debris flow events were coupled with plumes of atmospheric moisture transport with high values relative to the surrounding region, implying Atmospheric River-like conditions. This finding evokes a potential need to re-examine the metrics used to classify or characterize Atmospheric Rivers, particularly through the lens of their relationship to natural hazards. This research suggests… Advisors/Committee Members: Nolin, Anne W. (advisor), Daly, Chris (committee member).

Subjects/Keywords: debris flows; Debris avalanches – Oregon – Hood, Mount

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APA (6^th Edition):

Parker, L. E. (2009). Meteorological conditions associated with rain-related periglacial debris flows on Mount Hood, Oregon and Mount Rainier, Washington. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/11967

Chicago Manual of Style (16^th Edition):

Parker, Lauren E. “Meteorological conditions associated with rain-related periglacial debris flows on Mount Hood, Oregon and Mount Rainier, Washington.” 2009. Masters Thesis, Oregon State University. Accessed September 19, 2019. http://hdl.handle.net/1957/11967.

MLA Handbook (7^th Edition):

Parker, Lauren E. “Meteorological conditions associated with rain-related periglacial debris flows on Mount Hood, Oregon and Mount Rainier, Washington.” 2009. Web. 19 Sep 2019.

Vancouver:

Parker LE. Meteorological conditions associated with rain-related periglacial debris flows on Mount Hood, Oregon and Mount Rainier, Washington. [Internet] [Masters thesis]. Oregon State University; 2009. [cited 2019 Sep 19]. Available from: http://hdl.handle.net/1957/11967.

Council of Science Editors:

Parker LE. Meteorological conditions associated with rain-related periglacial debris flows on Mount Hood, Oregon and Mount Rainier, Washington. [Masters Thesis]. Oregon State University; 2009. Available from: http://hdl.handle.net/1957/11967

Hong Kong University of Science and Technology

20. Song, Dongri CIVL. Mechanisms of debris flow impact on rigid and flexible barriers.

Degree: 2016, Hong Kong University of Science and Technology

URL: https://doi.org/10.14711/thesis-b1781035 ; http://repository.ust.hk/ir/bitstream/1783.1-88902/1/th_redirect.html

► Debris flows carry enormous momentum as they surge downslope and could cause loss of lives and damage to infrastructure. Structural countermeasures such as rigid and… (more)

▼ Debris flows carry enormous momentum as they surge downslope and could cause loss of lives and damage to infrastructure. Structural countermeasures such as rigid and flexible barriers are commonly installed in mountainous regions to intercept debris flows. The current design approaches regard the debris flow as a uniform equivalent fluid without considering the solid-fluid interaction. Estimation of the debris flow impact, i.e., impact force and run-up height, remains semi-empirical. The objectives of this research are to reveal the mechanisms of debris-barrier interaction and solid-fluid interaction in the process of debris flow impact on rigid and flexible barriers. Findings of this study help to improve the current design practice. Two research methodologies, namely the centrifuge and numerical modelling, were adopted. To investigate the debris flow impact mechanisms, a broad range of geophysical flows were modelled condiering continuous variation of solid fraction, i.e., stream flow (less than 10% solid fraction), hyperconcentrated flow (debris flood), debris flow, and dry debris avalanche. Effects of boulders were studied separately by modelling the dry glass beads and dry glass bead-sand mixtures. A newly developed model flexible barrier together with a rigid barrier was used to simulate impermeable barriers with contrast in the barrier stiffness. Numerical modelling was used to back-analyse the centrifuge test results and investigate the effects of barrier stiffness by parametric study. Results from physical and numerical modelling are compared with the theoretical impact load models’ prediction. Discrepancies are found and the current impact models are revised based on the findings from this research. It is found that with an increase of solid fraction, an enlarging dead zone is observed at the base of barriers, denoting the contribution of grain frictional stress in the transition from run-up to pile-up impact mechanism. Due to the elongated interaction duration of pure fluid and two-phase flows, the peak loads on flexible barrier are reduced by 30% to 50% of the impact on rigid barrier. The boulder impact induced impulse load on rigid barrier could reach up to 6 times of the static load. Furthermore, due to reverse segregation of boulder-sand mixture, the boulders tend to migrate to the free surface and front of the flows without much reduction in velocity. With the combination of static load and boulder impulse load, the peak load of boulder-sand mixture impact could be even higher than that of pure boulder impact. A new impact load model adopting a triangular load distribution is proposed. A triangular load distribution highlights the contribution of static deposition in the peak impact force and the efficiency of frictional energy dissipation for dense two-phase flows like debris flow. The modelled flow types are further quantified by the friction number N_fric to reflect the degree of solid-fluid interaction. The friction number N_fric and square of Froude number Fr² form…

Subjects/Keywords: Debris avalanches; Protection; Mathematical models; Retaining walls

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APA (6^th Edition):

Song, D. C. (2016). Mechanisms of debris flow impact on rigid and flexible barriers. (Thesis). Hong Kong University of Science and Technology. Retrieved from https://doi.org/10.14711/thesis-b1781035 ; http://repository.ust.hk/ir/bitstream/1783.1-88902/1/th_redirect.html

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Song, Dongri CIVL. “Mechanisms of debris flow impact on rigid and flexible barriers.” 2016. Thesis, Hong Kong University of Science and Technology. Accessed September 19, 2019. https://doi.org/10.14711/thesis-b1781035 ; http://repository.ust.hk/ir/bitstream/1783.1-88902/1/th_redirect.html.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Song, Dongri CIVL. “Mechanisms of debris flow impact on rigid and flexible barriers.” 2016. Web. 19 Sep 2019.

Vancouver:

Song DC. Mechanisms of debris flow impact on rigid and flexible barriers. [Internet] [Thesis]. Hong Kong University of Science and Technology; 2016. [cited 2019 Sep 19]. Available from: https://doi.org/10.14711/thesis-b1781035 ; http://repository.ust.hk/ir/bitstream/1783.1-88902/1/th_redirect.html.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Song DC. Mechanisms of debris flow impact on rigid and flexible barriers. [Thesis]. Hong Kong University of Science and Technology; 2016. Available from: https://doi.org/10.14711/thesis-b1781035 ; http://repository.ust.hk/ir/bitstream/1783.1-88902/1/th_redirect.html

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Montana State University

21. Lutz, Eric Robert. Spatial and temporal analysis of snowpack strength and stability and environmental determinants on an inclined, forest opening.

Degree: College of Letters & Science, 2009, Montana State University

URL: https://scholarworks.montana.edu/xmlui/handle/1/1765

► Avalanche hazard evaluation relies on snowpack stability observations. Because snowpack properties can vary extensively over time and space, estimating slope-scale stability is difficult. This study… (more)

▼ Avalanche hazard evaluation relies on snowpack stability observations. Because snowpack properties can vary extensively over time and space, estimating slope-scale stability is difficult. This study addressed these challenges by implementing a methodology that 1. quantified spatial and temporal patterns of snowpack stability, 2. identified spatial associations between the strength and stability of a weak layer and slab load, and radiation properties, 3. identified internal associations between weak layer thickness, shear strength, microstructural properties, and slab load. An instability associated with a buried surface hoar weak layer was examined on an inclined forest opening at Lionhead, southwest Montana, during February and March, 2005. During five sampling days, 824 snow depth and SnowMicroPen resistance profiles and 352 shear frame tests were performed. An objective texture-based stratigraphic sampling approach was developed to obtain microstructural estimates of a stratigraphic weakness and instability from SnowMicroPen profiles, utilizing the coefficient of variation of rupture force. Spatial models of hemispheric sky visibility, and incoming long- and shortwave radiation were generated for the surface hoar formation period using a Geographic Information System and independent optical observations. Despite relative topographic uniformity, in a distance of 30 m, the buried surface hoar weak layer thicknesses varied between 3 - 21 mm. Before burial, the surface hoar persisted despite moderate winds and above freezing air temperatures. Spatial patterns of modeled incoming longwave and shortwave radiation explained the large variation in weak layer thickness and strength properties. Areas exposed to large amounts of radiation contained a strong, thin buried surface hoar layer, while in areas with limited incoming longwave (due to high sky visibility) and shortwave radiation (due to shading), the layer was thicker and possessed low shear and microstructural strengths. Over time, the shear frame stability index and SnowMicroPen-derived microstrength of the surface hoar layer increased and values became spatially more variable (divergence): it became harder to predict stability as the snowpack became more stable. A loading event then decreased stability and micro-strength and caused spatial uniformity (convergence), thereby increasing predictive strength of observations. The findings illustrate the usefulness of the SnowMicroPen for evaluating spatial patterns and load-related changes in snowpack stability. Advisors/Committee Members: Chairperson, Graduate Committee: Katherine J. Hansen. (advisor).

Subjects/Keywords: Avalanches.; Snow mechanics.; Snow Analysis.; Snow Research.

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APA (6^th Edition):

Lutz, E. R. (2009). Spatial and temporal analysis of snowpack strength and stability and environmental determinants on an inclined, forest opening. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/1765

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Lutz, Eric Robert. “Spatial and temporal analysis of snowpack strength and stability and environmental determinants on an inclined, forest opening.” 2009. Thesis, Montana State University. Accessed September 19, 2019. https://scholarworks.montana.edu/xmlui/handle/1/1765.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Lutz, Eric Robert. “Spatial and temporal analysis of snowpack strength and stability and environmental determinants on an inclined, forest opening.” 2009. Web. 19 Sep 2019.

Vancouver:

Lutz ER. Spatial and temporal analysis of snowpack strength and stability and environmental determinants on an inclined, forest opening. [Internet] [Thesis]. Montana State University; 2009. [cited 2019 Sep 19]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/1765.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Lutz ER. Spatial and temporal analysis of snowpack strength and stability and environmental determinants on an inclined, forest opening. [Thesis]. Montana State University; 2009. Available from: https://scholarworks.montana.edu/xmlui/handle/1/1765

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Montana State University

22. McCollister, Christopher Michael. Geographic knowledge discovery techniques for exploring historical weather and avalanche data.

Degree: College of Letters & Science, 2004, Montana State University

URL: https://scholarworks.montana.edu/xmlui/handle/1/1820

► Many ski areas, backcountry avalanche centers, highway departments, and helicopter ski operations record and archive daily weather and avalanche data. The objective of this thesis… (more)

▼ Many ski areas, backcountry avalanche centers, highway departments, and helicopter ski operations record and archive daily weather and avalanche data. The objective of this thesis is to present probabilistic techniques that allow avalanche forecasters to better utilize weather and avalanche data by incorporating a Geographic Information System with a modified meteorological nearest neighbors approach. This nearest neighbor approach utilizes evolving concepts related to visualizing geographic information stored in large databases. The resulting interactive database tool, Geographic Weather and Avalanche Explorer, allows the investigation of the relationships between specific weather parameters and the spatial pattern of avalanche activity. In order to validate these new techniques, two case studies are presented using over 10,000 individual avalanche events from the past 23 years that occurred at the Jackson Hole Mountain Resort. The first case study explores the effect of new snowfall, wind speed, and wind direction on the spatial patterns of avalanche activity. Patterns exist at the slide path scale, and for groups of adjacent slide paths, but not for either the entire region as a whole or when slide paths are grouped by aspect. Since wind instrumentation is typically located to measure an approximation of the free air winds, specific topography around a given path, and not aspect, is more important when relating wind direction to avalanche activity. The second case study explores the spatial variability of hard slab and dry loose avalanches, and characterizes these avalanche types with respect to their geographic location and associated weather conditions. I analyzed these data with and without the incorporation of three weather parameters (wind speed, 24-hour maximum temperature, and new snow density). Slide paths near each other often had similar proportions of hard slabs and a higher proportion of hard slabs occurred on exposed ridges. The proportion of loose avalanches also was similar for adjacent slide paths, and these paths were typically sheltered from strong winds. When I incorporated the three weather parameters I found significant increases in the average proportion of hard slabs with increases in new snow density, but not for changes in the 24-hour maximum temperature or wind speed. When I analyzed the proportion of loose avalanches associated with the three weather parameters I found a more direct relationship than with hard slabs. Changes in both wind speed and density significantly changed the average proportion of loose avalanches, with low wind and low density resulting in higher proportions of loose avalanches. My results quantify what operational avalanche forecasters have long known: Geographic location and weather are both related to the proportion of hard slab and dry loose avalanches. Advisors/Committee Members: Chairperson, Graduate Committee: Katherine J. Hansen. (advisor).

Subjects/Keywords: Avalanches.; Meteorology Research.

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APA (6^th Edition):

McCollister, C. M. (2004). Geographic knowledge discovery techniques for exploring historical weather and avalanche data. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/1820

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

McCollister, Christopher Michael. “Geographic knowledge discovery techniques for exploring historical weather and avalanche data.” 2004. Thesis, Montana State University. Accessed September 19, 2019. https://scholarworks.montana.edu/xmlui/handle/1/1820.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

McCollister, Christopher Michael. “Geographic knowledge discovery techniques for exploring historical weather and avalanche data.” 2004. Web. 19 Sep 2019.

Vancouver:

McCollister CM. Geographic knowledge discovery techniques for exploring historical weather and avalanche data. [Internet] [Thesis]. Montana State University; 2004. [cited 2019 Sep 19]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/1820.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

McCollister CM. Geographic knowledge discovery techniques for exploring historical weather and avalanche data. [Thesis]. Montana State University; 2004. Available from: https://scholarworks.montana.edu/xmlui/handle/1/1820

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Montana State University

23. Eversman, Sharon. A comparison of plant communities and substrates of avalanche and non-avalanche areas in South-Central Montana.

Degree: College of Agriculture, 1968, Montana State University

URL: https://scholarworks.montana.edu/xmlui/handle/1/5093

Subjects/Keywords: Botany.; Avalanches.; Ecology.

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APA (6^th Edition):

Eversman, S. (1968). A comparison of plant communities and substrates of avalanche and non-avalanche areas in South-Central Montana. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/5093

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Eversman, Sharon. “A comparison of plant communities and substrates of avalanche and non-avalanche areas in South-Central Montana.” 1968. Thesis, Montana State University. Accessed September 19, 2019. https://scholarworks.montana.edu/xmlui/handle/1/5093.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Eversman, Sharon. “A comparison of plant communities and substrates of avalanche and non-avalanche areas in South-Central Montana.” 1968. Web. 19 Sep 2019.

Vancouver:

Eversman S. A comparison of plant communities and substrates of avalanche and non-avalanche areas in South-Central Montana. [Internet] [Thesis]. Montana State University; 1968. [cited 2019 Sep 19]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/5093.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Eversman S. A comparison of plant communities and substrates of avalanche and non-avalanche areas in South-Central Montana. [Thesis]. Montana State University; 1968. Available from: https://scholarworks.montana.edu/xmlui/handle/1/5093

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Oregon State University

24. Casebeer, Nathan E. Sediment storage in a headwater valley of the Oregon Coast Range : erosion rates and styles and valley-floor capacitance.

Degree: MS, Geology, 2004, Oregon State University

URL: http://hdl.handle.net/1957/9014

► This study is part of the effort to quantify sediment budgets and understand the geomorphic evolution of steep mountains where debris flows are the dominant… (more)

▼ This study is part of the effort to quantify sediment budgets and understand the geomorphic evolution of steep mountains where debris flows are the dominant agent of upland erosion. Observations indicate that headwater basins in the Oregon Coast Range (OCR) can store a large amount of sediment, mostly from debris flows, in wide valley floors. In Bear Creek, a 2.23 km2 tributary basin of Knowles Creek, surveyed sediment volume in the main-stem valley was 6.95 x 104 m3. We hypothesize that, by storing sediment, headwater valleys in the OCR act as a sediment reservoir that buffers larger-basin reaches from episodic debris flows. These reservoirs are "well-mixed": they release sediment "cohorts" in proportion to their relative volumes in storage and, therefore, have an exponential distribution of sediment ages or residence times. This exponential distribution of residence times results from these valleys receiving pulse inputs of sediment at discrete times and producing gradual outputs of sediment representing a wide range of input times. We determined two separate residence time distributions in Bear Creek by dividing the main-stem valley into two reservoirs: lower and upper reaches. In each of these reaches, wood and/or charcoal from randomly selected sampling points in the valley sediment were dated by radiocarbon methods. The mean radiocarbon age from sediments in the upper-reach was 4.43 x 102 years. The mean radiocarbon age from sediments in the lower-reach was 1.22 x 103 years. The volume-weighted mean age of sediments in the entire main-stem valley was 9.96 x 102 years. Erosion rates of 0.013 - 0.038 mm/yr and 0.011 - 0.033 mm/yr for each of the upper 1.32 km2 and full 2.23 km2 basins, respectively, were calculated by dividing the volume of sediment by the mean age and the contributing area. A density correction for conversion of rock to sediment defines the lower limit with no density change defining the upper limit. These erosion rates are generally lower than those determined by other methods in the OCR possibly reflecting inherited age in radiocarbon dates plus denudation by processes that do not form deposits datable by radiocarbon. Such denudation processes include dissolution of bedrock and sediments and the direct discharging of soil from the hilislopes to the channel, transported as suspended load. In order to account for inherited radiocarbon ages and assuming that all denudation processes cycle sediment through the reservoirs datable by radiocarbon, we rescaled the residence time distributions using independently derived mean ages for the sediment. These mean residence times are 5.5 x 101 years for the upper-reach and 1.18 x 102 years for the lower-reach, respectively. These mean residence times are derived from an assumed basin average erosion rate of 0.1 mm/yr. A two-stage 8-corrected Kolmogorov-Smirnov statistical goodness-of-fit test was used to find whether the radiocarbon age distributions from the upper and lower reaches are statistically consistent with exponential distributions defined by the…

Subjects/Keywords: Debris avalanches – Oregon

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Casebeer, N. E. (2004). Sediment storage in a headwater valley of the Oregon Coast Range : erosion rates and styles and valley-floor capacitance. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/9014

Chicago Manual of Style (16^th Edition):

Casebeer, Nathan E. “Sediment storage in a headwater valley of the Oregon Coast Range : erosion rates and styles and valley-floor capacitance.” 2004. Masters Thesis, Oregon State University. Accessed September 19, 2019. http://hdl.handle.net/1957/9014.

MLA Handbook (7^th Edition):

Casebeer, Nathan E. “Sediment storage in a headwater valley of the Oregon Coast Range : erosion rates and styles and valley-floor capacitance.” 2004. Web. 19 Sep 2019.

Vancouver:

Casebeer NE. Sediment storage in a headwater valley of the Oregon Coast Range : erosion rates and styles and valley-floor capacitance. [Internet] [Masters thesis]. Oregon State University; 2004. [cited 2019 Sep 19]. Available from: http://hdl.handle.net/1957/9014.

Council of Science Editors:

Casebeer NE. Sediment storage in a headwater valley of the Oregon Coast Range : erosion rates and styles and valley-floor capacitance. [Masters Thesis]. Oregon State University; 2004. Available from: http://hdl.handle.net/1957/9014

University of Illinois – Urbana-Champaign

25. Leblanc, Michael P. Avalanches in plastic deformation: maximum velocity statistics, finite temperature effects, and analysis of low time resolution data.

Degree: PhD, Physics, 2016, University of Illinois – Urbana-Champaign

URL: http://hdl.handle.net/2142/93010

► In both crystalline and amorphous solids, plastic deformation consists of intermittent jumps called avalanches, whose sizes are power-law-distributed over a scaling regime. In this thesis,… (more)

▼ In both crystalline and amorphous solids, plastic deformation consists of intermittent jumps called avalanches, whose sizes are power-law-distributed over a scaling regime. In this thesis, we study the statistics of a simple mean-field avalanche model, with emphasis on both theoretical calculations and application to the analysis of experimental data on material deformation. We establish a relationship between the simple mean-field model and a continuous time model called the ABBM model, originally proposed as a phenomenological model of Barkhausen noise in magnets. The relationship is formally valid for ductile materials without significant weakening, but the results of our calculations are expected to apply to the small avalanches even in materials with high weakening. We then use the ABBM model to calculate several exact results concerning a system's maximum velocity during an avalanche. We find that the scaling of the maximum velocity distribution agrees with experiments on crystal plasticity. Left over from our calculations are several experimental predictions ready to be tested. The maximum velocity is a robust experimental observable and it has several distinct advantages over the more commonly-considered avalanche durations, so we expect our predictions to be useful in future tests of avalanche statistics in experimental systems. Then, motivated by recent creep deformation experiments that find scale-invariant avalanches, we develop a scaling theory for thermally-activated avalanches in the simple avalanche model near the critical point and at low temperature. We highlight several generic predictions for how statistical observables scale with temperature. Finally, we use the simple avalanche model to study how experimental avalanche measurements are influenced by the time resolution of the data. Using both experimental data and simulation data from the model, we determine how measured quantities change with resolution. From these relationships, we develop methods to diagnose when the time resolution low enough that it changes the measured avalanche statistics. We also propose a new analysis method that allows us to extract accurate size statistics from low-resolution data, and show that it is successful both on simulation data and downsampled high-resolution experimental data. Advisors/Committee Members: Dahmen, Karin A (advisor), Weaver, Richard L (Committee Chair), Weissman, Michael B (committee member), Cooper, S. Lance (committee member).

Subjects/Keywords: Avalanches; Nonequilibrium Statistical Mechanics; plastic deformation

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APA (6^th Edition):

Leblanc, M. P. (2016). Avalanches in plastic deformation: maximum velocity statistics, finite temperature effects, and analysis of low time resolution data. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/93010

Chicago Manual of Style (16^th Edition):

Leblanc, Michael P. “Avalanches in plastic deformation: maximum velocity statistics, finite temperature effects, and analysis of low time resolution data.” 2016. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed September 19, 2019. http://hdl.handle.net/2142/93010.

MLA Handbook (7^th Edition):

Leblanc, Michael P. “Avalanches in plastic deformation: maximum velocity statistics, finite temperature effects, and analysis of low time resolution data.” 2016. Web. 19 Sep 2019.

Vancouver:

Leblanc MP. Avalanches in plastic deformation: maximum velocity statistics, finite temperature effects, and analysis of low time resolution data. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2016. [cited 2019 Sep 19]. Available from: http://hdl.handle.net/2142/93010.

Council of Science Editors:

Leblanc MP. Avalanches in plastic deformation: maximum velocity statistics, finite temperature effects, and analysis of low time resolution data. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2016. Available from: http://hdl.handle.net/2142/93010

Université de Grenoble

26. Caccamo, Paolo. Experimental study of the influence of protection structures on avalanches and impact pressures : Etude expérimentale de l'influence des structures de protection sur les avalanches et pressions d'impact.

Degree: Docteur es, Sciences de la terre et de l'univers, et de l'environnement, 2012, Université de Grenoble

URL: http://www.theses.fr/2012GRENU043

►

L'auteur n'a pas fourni de résumé en français

Experimental study of the influence of protection structures on avalanches and impact pressures Abstract: In the frame… (more)

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L'auteur n'a pas fourni de résumé en français

Experimental study of the influence of protection structures on avalanches and impact pressures Abstract: In the frame of snow avalanche protection, the optimisation of defence structure design depends on the understanding of the flow dynamics and on a exhaustive knowledge of the flow-obstacle interaction. The study presented here utilises a mainly experimental approach. Small-scale laboratory tests were combined with field measurements and observations. Dense snow avalanches are modelled by granular materials. Dry cohesionless and mono-dispersed glass beads are released down an inclined channel. Reference tests (with no obstacles) were carried out in order to characterise the flow dynamic properties, and an obstacle was then mounted and force measurements were taken. The geometry of two obstacles was tested: a large wall spanning the whole width of the flow and a narrower wall allowing lateral flows. Results showed that an influence zone forms uphill from the obstacle and plays an important role in the flow dynamics. An analysis of this zone was carried out, together with precise measurements of the flow depth (laser technique), surface velocity (PIV) and impact forces (force sensors). In relation to density currents, powder snow avalanches are modelled by a dyed salt solution flowing down an inclined channel immersed in a water tank. We investigated the influence of two different catching-dam-type obstacles on the flow behaviour with respect to reference conditions. The maximum flow height and its front and core velocity were measured by means of image processing and ultrasound Doppler velocimetry. Results mainly showed the higher effectiveness of a dam with vertical uphill face rather than inclined and underscored the importance of the velocity norm in the computation of the total incoming flow velocity. In-situ full-scale measurements complement small-scale laboratory tests. A new full-scale experimental site was implemented on the existing avalanche defence system of Taconnaz (Chamonix, France). Three breaking mounds were equipped with velocity and pressure sensors. The reference event, the rough site conditions, the need for data synchronization and remote access defined the design constraints. In December 2010, the first event was recorded, which proved that the conceived system works effectively and also provided the first set of data. Preliminary results showed very high pressure peaks with high impact pressures even for low velocity regimes and thus a drag coefficient which increases when the Froude number decreases. Isolated rocks or ice blocks struck the sensors, contributing significantly to the total energy released by the avalanche. This work provided effective inputs for numerical and analytical models and enhanced the current knowledge of avalanche dynamics in order to optimise the future design guidelines for avalanche protection structures. Keywords: Snow avalanches, impact pressure, laboratory experiments, dense avalanches, granular flows, influence…

Advisors/Committee Members: Naaim-Bouvet, Florence (thesis director), Faug, Thierry (thesis director).

Subjects/Keywords: Avalanches; Pressions; Ouvrages; Granulaire; Courant de gravité; Avalanches; Pressures; Protection structures; Granular; Gravity current; 550

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APA (6^th Edition):

Caccamo, P. (2012). Experimental study of the influence of protection structures on avalanches and impact pressures : Etude expérimentale de l'influence des structures de protection sur les avalanches et pressions d'impact. (Doctoral Dissertation). Université de Grenoble. Retrieved from http://www.theses.fr/2012GRENU043

Chicago Manual of Style (16^th Edition):

Caccamo, Paolo. “Experimental study of the influence of protection structures on avalanches and impact pressures : Etude expérimentale de l'influence des structures de protection sur les avalanches et pressions d'impact.” 2012. Doctoral Dissertation, Université de Grenoble. Accessed September 19, 2019. http://www.theses.fr/2012GRENU043.

MLA Handbook (7^th Edition):

Caccamo, Paolo. “Experimental study of the influence of protection structures on avalanches and impact pressures : Etude expérimentale de l'influence des structures de protection sur les avalanches et pressions d'impact.” 2012. Web. 19 Sep 2019.

Vancouver:

Caccamo P. Experimental study of the influence of protection structures on avalanches and impact pressures : Etude expérimentale de l'influence des structures de protection sur les avalanches et pressions d'impact. [Internet] [Doctoral dissertation]. Université de Grenoble; 2012. [cited 2019 Sep 19]. Available from: http://www.theses.fr/2012GRENU043.

Council of Science Editors:

Caccamo P. Experimental study of the influence of protection structures on avalanches and impact pressures : Etude expérimentale de l'influence des structures de protection sur les avalanches et pressions d'impact. [Doctoral Dissertation]. Université de Grenoble; 2012. Available from: http://www.theses.fr/2012GRENU043

Université de Grenoble

27. Hagenmuller, Pascal. Modélisation du comportement mécanique de la neige à partir d'images microtomographiques : Modeling snow mechanics with microtomographic images.

Degree: Docteur es, Sciences de la terre et de l'univers, et de l'environnement, 2014, Université de Grenoble

URL: http://www.theses.fr/2014GRENU042

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Caractériser les propriétés mécaniques de la neige est un défi majeur pour la prévision et la prédétermination du risque d’avalanche. Du fait du grand nombre… (more)

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Caractériser les propriétés mécaniques de la neige est un défi majeur pour la prévision et la prédétermination du risque d’avalanche. Du fait du grand nombre de types de neige et de la difficulté à effectuer des mesures sur ce matériau très fragile, la compréhension de la relation entre la microstructure de la neige et ses propriétés mécaniques est encore incomplète. Cette thèse aborde ce problème par le biais d’une approche de modélisation mécanique basée sur la microstructure tridimensionnelle de neige obtenue par microtomographie aux rayons X. Tout d’abord, afin d’automatiser et améliorer la segmentation des images microtomographiques, un nouvel algorithme tirant profit de la minimisation de l’énergie de surface de la neige a été développé et évalué. L’image air-glace est ensuite utilisée comme entrée géométrique d’un modèle éléments finis où la glace est supposée élastique fragile. Ce modèle permet de reproduire le comportement fragile en traction et révèle le comportement pseudoplastique apparent causé par l’endommagement microscopique, ainsi que la forte hétérogénéité des contraintes dans la matrice de glace. Pour reproduire les grandes déformations impliquant le ré-arrangement de grains, un modèle par éléments discrets a ensuite été développé. Les grains sont identifiés dans la microstructure en utilisant des critères géométriques dont la pertinence mécanique a été démontrée, et décrits dans le modèle par des blocs rigides de sphères. Le comportement simulé en compression est dominé par le rôle de la densité mais révèle également des différences liées au type de neige. Enfin, pour distinguer le degré de cohésion entre les types de neige, un indicateur microstructurel a été développé et s’est avéré être fortement corrélé aux propriétés mécaniques et physiques du matériau.

Characterizing the complex microstructure of snow and its mechanics is a major challenge for avalanche forecasting and hazard mapping. While the effect of environmental conditions on the snow metamorphism, which leads to numerous snow types, is fairly known, the relation between snow microstructure and mechanical properties is poorly understood because of the very fragile nature of snow. In order to decipher this relation for dry snow, this thesis presents a modeling approach of snow mechanics based on the three-dimensional microstructure of snow captured by X-ray microtomography and the properties of ice. First, in order to automatically process the microtomographic data, we take advantage of the minimization of the snow surface energy through metamorphism to efficiently binary segment grayscale images. Second, assuming an elastic brittle behavior of the ice matrix, the tensile strength of snow is modeled via a finite element approach. The model reveals an apparent pseudo-plastic behavior caused by damage, and the highly heterogenous stress distribution in the ice matrix. Third, we develop a discrete element model, accounting for grain-rearrangements and the creation/failure of inter-granular contacts. The grains, geometric input of the…

Advisors/Committee Members: Naaim, Mohamed (thesis director).

Subjects/Keywords: Microstructure; Neige; Microtomographie; Mécanique; Segmentation; Avalanches; Microstructure; Snow; Microtomography; Mechanics; Segmentation; Avalanches; 550; 530

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APA (6^th Edition):

Hagenmuller, P. (2014). Modélisation du comportement mécanique de la neige à partir d'images microtomographiques : Modeling snow mechanics with microtomographic images. (Doctoral Dissertation). Université de Grenoble. Retrieved from http://www.theses.fr/2014GRENU042

Chicago Manual of Style (16^th Edition):

Hagenmuller, Pascal. “Modélisation du comportement mécanique de la neige à partir d'images microtomographiques : Modeling snow mechanics with microtomographic images.” 2014. Doctoral Dissertation, Université de Grenoble. Accessed September 19, 2019. http://www.theses.fr/2014GRENU042.

MLA Handbook (7^th Edition):

Hagenmuller, Pascal. “Modélisation du comportement mécanique de la neige à partir d'images microtomographiques : Modeling snow mechanics with microtomographic images.” 2014. Web. 19 Sep 2019.

Vancouver:

Hagenmuller P. Modélisation du comportement mécanique de la neige à partir d'images microtomographiques : Modeling snow mechanics with microtomographic images. [Internet] [Doctoral dissertation]. Université de Grenoble; 2014. [cited 2019 Sep 19]. Available from: http://www.theses.fr/2014GRENU042.

Council of Science Editors:

Hagenmuller P. Modélisation du comportement mécanique de la neige à partir d'images microtomographiques : Modeling snow mechanics with microtomographic images. [Doctoral Dissertation]. Université de Grenoble; 2014. Available from: http://www.theses.fr/2014GRENU042

28. Liu, Chen. Dynamique critique à la transition d'écoulement et comportements de fluage des systèmes amorphes : modélisation mésoscopique : Critical dynamics at the yielding transition and creep behavior of amorphous systems : mesoscopic modeling.

Degree: Docteur es, Physique théorique, 2016, Grenoble Alpes

URL: http://www.theses.fr/2016GREAY066

► Les systèmes amorphes "mous", loin de leur transition vitreuse, comprennent les verres colloïdaux de hautefraction volumique, les émulsions concentrées, les mousses, etc...L’échelle de temps pour… (more)

▼ Les systèmes amorphes "mous", loin de leur transition vitreuse, comprennent les verres colloïdaux de hautefraction volumique, les émulsions concentrées, les mousses, etc...L’échelle de temps pour leur relaxationmicroscopique est divergente, et ils ne se mettent en écoulement que lorsque la contraint appliquée estsuffisamment grande. Cette transition dynamique d’un état apparemment solide à un état apparemmentliquide, suivant la contrainte imposée, est appelé transition d’écoulement. Cette transition est étudiéedans cette thèse par l’intermédiaire d’une modélisation mésoscopique, basé sur un modèle d’élémentsélasto-plastiques en interaction.Après une brève introduction à la transition vitreuse et aux systèmes réels supposés être décrit parle modèle élast-plastique, une formulation du modèle différente de celle qui est habituellement présentéedans la littérature est introduite, pour à la fois incorporer les protocole à taux de cisaillement fixé et leprotocole à contraint fixée. A travers des approximations, un modèle mésoscopique de type champ-moyen(à l’origine décrit par Hébraud et Lequeux) est déduit à partir du modèle elasto-plastique qui contient lesinformations spatiales.En appliquant le protocole à taux de cisaillement fixé, le transition d’écoulement est dans un premiertemps étudiée à travers la dépendance de la statistique des avalanches (chutes de contrainte) en taux decisaillement. Une transition d’un comportement de champ moyen à un comportement corrélé est observéen variant le taux de cisaillement. Les lois d’échelle observées dans la limite des petits taux de cisaillementsupportent l’idée que la transition d’écoulement appartient à une certaine classe d’universalité de transitiondynamique. L’étude de la symétrie de la forme moyenne des chutes de contrainte en fonction de leur durée,de la taille de système et du taux de cisaillement appliqué, conduit à l’interprétation que les chutes decontrainte résultent d’une superposition d’avalanches individuelles possédant une longueur coopérative etun temps coopératif.En étudiant les fluctuations de contrainte macroscopique, la longueur coopérative l_c est identifiéepar un crossover en taille de système en-dessous de laquelle le loi d’échelle avec la taille de système1/L^d impliquée par la théorème de limite centrale, ne fonctionne plus. En complément, une échelle detemps de saturation T_c est trouvé dans le séries temporaire de taux de cisaillement plastique, tempsen-dessous duquel la dynamique de la contrainte peut être décrite par un mouvement Brownien. Le tempsde saturation, pour les systèmes de taille plus petit que l_c obéit à une loi d’échelle avec la taille de systèmeT_c~(l_c)^z. Cette dernière peut être interprétée comme la loi d’échelle entre la longueur coopérative et letemps coopératif des avalanches individuelles.En appliquant le protocole de contrainte imposée, la transition d’écoulement est étudiée en simulantdes expériences de fluage sur les systèmes amorphes. Les modèles mésoscopiques (le modèle elasto-plastiqueet le modèle champ moyen de… Advisors/Committee Members: Barrat, Jean-Louis (thesis director), Martens, Kirsten (thesis director).

Subjects/Keywords: Verres; Avalanches; Fluage; Dynamique coopérative; Transition d'écoulement; Glasses; Avalanches; Creep; Cooperative dynamics; Yielding transition; 530

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Liu, C. (2016). Dynamique critique à la transition d'écoulement et comportements de fluage des systèmes amorphes : modélisation mésoscopique : Critical dynamics at the yielding transition and creep behavior of amorphous systems : mesoscopic modeling. (Doctoral Dissertation). Grenoble Alpes. Retrieved from http://www.theses.fr/2016GREAY066

Chicago Manual of Style (16^th Edition):

Liu, Chen. “Dynamique critique à la transition d'écoulement et comportements de fluage des systèmes amorphes : modélisation mésoscopique : Critical dynamics at the yielding transition and creep behavior of amorphous systems : mesoscopic modeling.” 2016. Doctoral Dissertation, Grenoble Alpes. Accessed September 19, 2019. http://www.theses.fr/2016GREAY066.

MLA Handbook (7^th Edition):

Liu, Chen. “Dynamique critique à la transition d'écoulement et comportements de fluage des systèmes amorphes : modélisation mésoscopique : Critical dynamics at the yielding transition and creep behavior of amorphous systems : mesoscopic modeling.” 2016. Web. 19 Sep 2019.

Vancouver:

Liu C. Dynamique critique à la transition d'écoulement et comportements de fluage des systèmes amorphes : modélisation mésoscopique : Critical dynamics at the yielding transition and creep behavior of amorphous systems : mesoscopic modeling. [Internet] [Doctoral dissertation]. Grenoble Alpes; 2016. [cited 2019 Sep 19]. Available from: http://www.theses.fr/2016GREAY066.

Council of Science Editors:

Liu C. Dynamique critique à la transition d'écoulement et comportements de fluage des systèmes amorphes : modélisation mésoscopique : Critical dynamics at the yielding transition and creep behavior of amorphous systems : mesoscopic modeling. [Doctoral Dissertation]. Grenoble Alpes; 2016. Available from: http://www.theses.fr/2016GREAY066

29. Valencia, Camilo Akimushkin. Avalanches e redes complexas no modelo Kinouchi-Copelli.

Degree: Mestrado, Física Básica, 2012, University of São Paulo

URL: http://www.teses.usp.br/teses/disponiveis/76/76131/tde-24102012-113159/ ;

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A capacidade de um sistema sensorial detectar estímulos eficientemente é tradicionalmente dimensionada pela faixa dinâmica, que é simplesmente uma medida da extensão do intervalo de… (more)

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A capacidade de um sistema sensorial detectar estímulos eficientemente é tradicionalmente dimensionada pela faixa dinâmica, que é simplesmente uma medida da extensão do intervalo de intensidades de estímulo para as quais a rede é suficientemente sensível. Muitas vezes, sistemas biológicos exibem largas faixas dinâmicas, que abrangem diversas ordens de magnitude. A compreensão desse fenômeno não é trivial, haja vista que todos os neurônios apresentam janelas de sensibilidade muito estreitas. Tentativas de explicação baseadas em argumentos de recrutamento sequencial dos neurônios sensoriais, com efeitos essencialmente aditivos, simplesmente não são realísticas, haja vista que seria preciso que os limiares de ativação das unidades também apresentassem um escalonamento por várias ordens de magnitude, para cobrir a faixa dinâmica empiricamente observada em nível macroscópico. Notavelmente, o modelo Kinouchi-Copelli (KC), que carrega o nome de seus idealizadores, mostrou que aquele comportamento pode ser um efeito coletivo (não aditivo) do conjunto de neurônios sensoriais. O modelo KC é uma rede de unidades excitáveis com dinâmicas estocásticas e acoplados segundo uma topologia de grafo aleatório. Kinouchi e Copelli mostraram que a taxa espontânea de disparo dos neurônios (ou atividade média) sinaliza uma transição de fase fora do equilíbrio do tipo ordem-desordem, e que exatamente no ponto crítico desta transição (em termos de um parâmetro ligado às características estruturais da rede) a sensibilidade a estímulos externos é máxima, ou seja, a faixa dinâmica exibe uma otimização crítica. Neste trabalho, investigamos como o ponto crítico depende da topologia, utilizando os modelos mais comuns das chamadas redes complexas. Além disso, estudamos computacionalmente os padrões de atividade (avalanches neuronais) exibidos pelo modelo, com especial atenção às mudanças qualitativas de comportamento devido às mudanças de topologia. Comentaremos também a relação desses resultados com experimentos recentes de monitoramento de dinâmicas neurais.

The capacity of a sensory system in efficiently detecting stimuli is usually given by the dynamic range, a simple measure of the range of stimulus intensity over which the network is sensible enough. Many times biological systems exhibit large dynamic ranges, covering many orders of magnitude. There is no easy explanation for that, since individual neurons present very short dynamic ranges isolatedly. Arguments based on sequential recruitment are doomed to failure since the corresponding arrangement of the limiar thresholds of the units over many orders of magnitude is unrealistic. Notably the so-called Kinouchi-Copelli (KC) model strongly suggested that large dynamic range should be a collective effect of the sensory neurons. The KC model is a network of stochastic excitable elements coupled as a random graph. KC showed the spontaneous activity of the network signals an order-disorder nonequilibrium phase transition and that the dynamic range exhibits an optimum precisely at the critical…

Advisors/Committee Members: Maia, Leonardo Paulo.

Subjects/Keywords: Avalanches; Avalanches; Complex Networks; Critical Phenomena; Fenômenos críticos; Kinouchi-Copelli model; Modelo de Kinouchi-Copelli; Psicofísica; Psychophysics; Redes Complexas

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Valencia, C. A. (2012). Avalanches e redes complexas no modelo Kinouchi-Copelli. (Masters Thesis). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/76/76131/tde-24102012-113159/ ;

Chicago Manual of Style (16^th Edition):

Valencia, Camilo Akimushkin. “Avalanches e redes complexas no modelo Kinouchi-Copelli.” 2012. Masters Thesis, University of São Paulo. Accessed September 19, 2019. http://www.teses.usp.br/teses/disponiveis/76/76131/tde-24102012-113159/ ;.

MLA Handbook (7^th Edition):

Valencia, Camilo Akimushkin. “Avalanches e redes complexas no modelo Kinouchi-Copelli.” 2012. Web. 19 Sep 2019.

Vancouver:

Valencia CA. Avalanches e redes complexas no modelo Kinouchi-Copelli. [Internet] [Masters thesis]. University of São Paulo; 2012. [cited 2019 Sep 19]. Available from: http://www.teses.usp.br/teses/disponiveis/76/76131/tde-24102012-113159/ ;.

Council of Science Editors:

Valencia CA. Avalanches e redes complexas no modelo Kinouchi-Copelli. [Masters Thesis]. University of São Paulo; 2012. Available from: http://www.teses.usp.br/teses/disponiveis/76/76131/tde-24102012-113159/ ;

30. Dunning, Stuart A. Rock avalanches in high mountains.

Degree: PhD, 2004, University of Bedfordshire

URL: http://hdl.handle.net/10547/322902

► Rock avalanches are a high magnitude, low frequency catastrophic mass movement involving the failure of over 1 x 106 m3 of mountainside. Rock avalanches are… (more)

▼ Rock avalanches are a high magnitude, low frequency catastrophic mass movement involving the failure of over 1 x 106 m3 of mountainside. Rock avalanches are considered a major hazard of the high mountains due to the excessive run-out often associated with them. To date the mechanism that allows for such excessive travel distance is unproven although several dozen possibilities have been proposed. Rock-avalanche deposits exhibit characteristic features such as sharp lateral margins, confinement to local topography, super-elevation on valley sides, intensely fragmented interiors and preserved stratigraphy relative to the source. However, there are few detailed studies of the internal sedimentology of rock-avalanche deposits. Such studies are a vital piece of evidence in the search for the mechanisms of motion as rock avalanches are rarely witnessed. This thesis examines the detailed sedimentology of five rock avalanche deposits of varied lithology and morphology. A novel methodology is developed to sample deposits for their grainsize distributions (GSD). The GSD's prove similar for deposits, with significant variation due to preserved lithological banding in the interior. This finding refutes the commonly held view that rock-avalanche deposits are simply inversely graded. Instead, a facies model is developed of a coarse Carapace facies forming the surface and near surface that overlies a highly fragmented Body facies that is in turn underlain by the Basal facies that is free to interact with the substrate. The sedimentology of the Body facies is considered in fine detail and is shown to be fractal in nature, that is, self-similar at all scales of observation. A predictive sedimentological plot is presented that allows generation of the grain-size distribution and descriptive statistics from a simple estimation of weight percent gravel at a rock avalanche exposure. The morphology of rock-avalanche deposits are examined and a classification presented of 'spread' 'two-phase' and 'stalled'. The hazard and features of each morphology is described in relation to the observed deposits.

Subjects/Keywords: 551.3; F643 Quaternary studies; avalanches; rock avalanches

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Dunning, S. A. (2004). Rock avalanches in high mountains. (Doctoral Dissertation). University of Bedfordshire. Retrieved from http://hdl.handle.net/10547/322902

Chicago Manual of Style (16^th Edition):

Dunning, Stuart A. “Rock avalanches in high mountains.” 2004. Doctoral Dissertation, University of Bedfordshire. Accessed September 19, 2019. http://hdl.handle.net/10547/322902.

MLA Handbook (7^th Edition):

Dunning, Stuart A. “Rock avalanches in high mountains.” 2004. Web. 19 Sep 2019.

Vancouver:

Dunning SA. Rock avalanches in high mountains. [Internet] [Doctoral dissertation]. University of Bedfordshire; 2004. [cited 2019 Sep 19]. Available from: http://hdl.handle.net/10547/322902.

Council of Science Editors:

Dunning SA. Rock avalanches in high mountains. [Doctoral Dissertation]. University of Bedfordshire; 2004. Available from: http://hdl.handle.net/10547/322902

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