Browsing Norwegian Geotechnical Institute (NGI) Digital Archive by Author "Birkeland, Karl W."
Now showing items 1-7 of 7
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Associations between shear strength of a buried surface hoar layer and stratigraphic, topographic and vegetation characteristics on a uniform slope. Extended abstract
Lutz, Eric; Birkeland, Karl W.; Schneebeli, Martin; Hansen, Kathy J.; Kronholm, Kalle (The International Snow Science Workshop (ISSW) Proceedings;, Chapter, 2006)In this study we quantify 1) changes in spatial and aspatial characteristics of the shear strength of a buried surface hoar layer, and 2) identify characteristics in terrain, vegetation and snow stratigraphy that can help ... -
Field measurements of sintering after fracture of snowpack weak layers
Birkeland, Karl W.; Kronholm, Kalle; Logan, Spencer; Schweizer, Jürg (Journal article, 2006)This research documents two cases where field workers unintentionally fractured a snowpack weak layer, but no avalanche released. Measurements from before and after the fractures provide unique data sets on the temporal ... -
Integrating spatial patterns into a snow avalanche cellular automata model
Kronholm, Kalle; Birkeland, Karl W. (Journal article, 2005)Snow avalanches are a major mountain hazard that kills hundreds of people and causes millions of dollars in damage worldwide annually. Yet, the relationship between the well-documented spatial variability of the snowpack ... -
Reliability of sampling designs for spatial snow surveys
Kronholm, Kalle; Birkeland, Karl W. (Journal article, 2007)Spatial patterns are an inherent property of most naturally occurring materials at a large range of scales. To describe spatial patterns in the field, several observations are made according to a certain sampling design. ... -
Review of spatial variability of snowpack properties and its importance for avalanche formation.
Schweizer, Jürg; Kronholm, Kalle; Jamieson, J.Bruce; Birkeland, Karl W. (Journal article, 2008)The seasonal snow cover is spatially variable. Spatial variability of layer properties is due to various external and internal process drivers interacting with terrain and ground cover during and after the deposition ... -
Surface hoar characteristics derived from a snow micropenetrometer using moving window statistical operations
Lutz, Eric; Birkeland, Karl W.; Kronholm, Kalle; Hansen, Kathy; Aspinall, Richard (Journal article, 2007)This study aims to improve analytical techniques for studying stratigraphic dimensions and hardness characteristics of thin weak layers in the mountain snowpack, with particular interest to buried surface hoar layers. By ... -
Temporal changes in the spatial variability of shear strength and stability.
Logan, Spencer; Birkeland, Karl W.; Kronholm, Kalle; Hansen, Kathy (The International Snow Science Workshop (ISSW) Proceedings;, Chapter, 2006)Avalanche forecasting involves the prediction of spatial and temporal variability of the snowpack. To predict avalanches with more accuracy it is important to determine whether the snowpack is becoming more spatially ...