Blar i Norwegian Geotechnical Institute (NGI) Digital Archive på forfatter "Kristensen, Krister"

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    • GIS aided avalanche warning in Norway. 

      Jaedicke, Christian; Kronholm, Kalle; Kristensen, Krister; Bakkehøi, Steinar (The International Snow Science Workshop (ISSW) Proceedings;, Chapter, 2008)
      By 2008 detailed avalanche warning for the entire Norway is not available. The Norwegian Meteorological Institute only issues a general warning for large regions of the country for danger level 4 or 5, mainly based on ...

    • The Godtifonn avalanche 

      Kleemayr, Karl; Mayerl, Markus; Sailer, Rudolf; Kristensen, Krister; Pürstinger, Christian; Walter, Gerhard (Journal article, 2007)
      The group also had the chance to visit the Godtifonn avalanche track located about 25 km west of Stryn. 1 1/2 years previously, a huge avalanche event released and impacted one of the most important transnational roads ...

    • Human error revisited 

      Kristensen, Ida; Kristensen, Krister (The International Snow Science Workshop (ISSW) Proceedings;, Chapter, 2012)
      It is often reported that a majority of avalanche accidents, as well as accidents in other fields, are caused by human error. In these accident analyses, the accidents are attributed to the "human factor". This factor is ...

    • Monitoring snow avalanches in Grasdalen using an infrasound array 

      Gilbert, Graham; Kristensen, Krister (NGI-rapport;20170131-18-TN, Research report, 2020-06-26)
      The absence of near real-time information about the avalanche activity is a significant challenge for local avalanche forecasting (Schweizer and van Herwijnen 2013). Information about avalanche activity in neighboring paths ...

    • The Norwegian avalanche test site - Ryggfonn 

      Kleemayr, Karl; Kristensen, Krister; Mayerl, Markus; Pürstinger, Christian; Walter, Gerhard (Journal article, 2007)
      In 1981, NGI established the full scale avalanche test site at Ryggfonn. Since then the site has been fitted with an increasing number of sensors and instruments.

    • Observations of the dynamic structure of snow avalanches 

      Nishimura, K.; Maeno, N.; Kristensen, Krister; Sandersen, Frode; Norem, Harald; Lied, Karstein (Journal article, 1993)
      During two winters, 1990–92, the dynamic structures of snow avalanches were studied in western Norway. Artificially released wet-snow avalanches ran down the avalanche chute and stopped in front of the retaining dam. Running ...

    • On avalanche measurements at the Norwegian full-scale test-site Ryggfonn. 

      Gauer, Peter; Lied, Karstein; Kristensen, Krister (The International Snow Science Workshop (ISSW) Proceedings;, Chapter, 2008)
      Avalanche measurements and observations, which were carried out at the Ryggfonn test-site, Norway, on 16 April 2005, are analyzed. The data include pulsed Doppler radar measurements, impact pressure readings from load cells ...

    • On full-scale avalanche measurements at the Ryggfonn test site, Norway. 

      Gauer, Peter; Issler, Dieter; Lied, Karstein; Kristensen, Krister; Iwe, H.; Lied, Erik; Rammer, L.; Schreiber, H. (Journal article, 2007)
      Avalanche measurements carried out at the Ryggfonn test site, Norway, during several winter seasons are analyzed with emphasis on recognizing different flow regimes and estimating flow densities. Measurements include impact ...

    • On pulsed Doppler radar measurements of avalanches and their implication to avalanche dynamics. 

      Gauer, Peter; Kern, Martin; Kristensen, Krister; Lied, Karstein; Rammer, Lambert; Schreiber, Helmut (Journal article, 2007)
      Pulsed Doppler radar measurements from several avalanche releases are analyzed to gain an in-depth understanding of avalanche dynamics. A pulsed Doppler radar emits short pulses and samples the echo in distinct time ...

    • On snow avalanche flow regimes: Inferences from observations and measurements. 

      Gauer, Peter; Issler, Dieter; Lied, Karstein; Kristensen, Krister; Sandersen, Frode (The International Snow Science Workshop (ISSW) Proceedings;, Chapter, 2008)
      Mixed dry-snow avalanches are commonly thought to consist of a dense core and a dilute suspension layer, even though observations and measurements from Canada and Russia have long indicated the presence of an intermediate-density ...

    • Optimization and probabilistic calibration of avalanche block models 

      Gauer, Peter; Medina-Cetina, Zenon; Lied, Karstein; Kristensen, Krister (Journal article, 2009)
      The Norwegian Geotechnical Institute (NGI) has been performing full-scale avalanche tests at Ryggfonn in western Norway for more than 30 years. During those years, measurements from about three dozen dry-snow avalanches ...

    • Particle simulation of snow avalanche motion 

      Perla, R.; Lied, Karstein; Kristensen, Krister (Journal article, 1984)
      The continuum model of a snow avalanche is abandoned, and instead an avalanche is modeled as a collection of particles that move randomly and independently subject to gravity and resistive forces which have a random ...

    • Perception of risk in avalanche terrain 

      Kristensen, Krister; Genswein, Manuel; Munter, Werner (The International Snow Science Workshop (ISSW) Proceedings;, Chapter, 2012)
      Although avalanche training and the risk minimization strategies have greatly evolved and are being widely taught to recreational and professional users, too many serious accidents continue to happen within the educated ...

    • Probabilistic calibration of avalanche block models. 

      Gauer, Peter; Medina-Cetina, Zenon; Lied, Karstein; Kristensen, Krister (The International Snow Science Workshop (ISSW) Proceedings;, Chapter, 2008)
      The Norwegian Geotechnical Institute (NGI) has been operating the full-scale avalanche test-site Ryggfonn in western Norway for more than 25 years. During those years, measurements from about three dozen dry-snow avalanches ...

    • Radar measurements of snow avalanche full scale experiment in Ryggfonn. 

      Rammer, Lambert; Kristensen, Krister; Lied, Karstein (NGI Publication;203, Chapter, 1998)
      At the full scale experiment site of NG! in Ryggfonn, avalanche velocities and forces have been measured through 15 years. In April 1997 an Austrian developed INW pulsed Doppler radar was used to measure avalanche velocities ...

    • Risk management with mandatory upper risk threshold in the world's largest mountaineering school 

      Genswein, Manuel; Kristensen, Krister (The International Snow Science Workshop (ISSW) Proceedings;, Chapter, 2013)
      At the beginning of the new millennium, the DAV Summit Club, the commercial mountaineering school of the German Alpine Club and world’s largest provider of commercial mountaineering has developed a risk frame work with ...

    • Road traffic and avalanches - methods for risk evaluation and risk management 

      Kristensen, Krister; Harbitz, Carl Bonnevie; Harbitz, Alf (Journal article, 2003)
      This paper considers the methods for risk analysis and management in connection with avalanches and road traffic. Examples with calculations of encounter probability and quantification of uncertainty are given, along with ...

    • The Ryggfonn project. Avalanche data from the winters 1994/95 and 1995/96 

      Kristensen, Krister (NGI-rapport;58120-32, Research report, 1997-12-20)
      This report presents data collected from the full-scale Ryggfonn project during the winters 1994/95 and 1995/95. Only four avalanches were observed in the course of these two winters, three of which were naturally released ...

    • The Ryggfonn project. Avalanche data from the winters 1996/97, 1997/1998, 1998/1999 and 1999/2000 

      Kristensen, Krister (NGI-rapport;58120-33, Research report, 2001-11-01)
      This report presents data collected from the full-scale Ryggfonn project during the winters 1996/1997, 1997/1998, 1998/1999 and 1999/2000. The weather and snow conditions and avalanches characteristics are summarised. The ...

    • Significance of historical records for avalanche hazard zoning in Norway 

      Kristensen, Krister; Harbitz, Carl Bonnevie; Harbitz, Alf (The International Snow Science Workshop (ISSW) Proceedings;, Chapter, 2000)
      In avalanche hazard zoning, it is common practice to investigate the previous avalanche history for the area considered. Historical observations of avalanches serve as an aid in the classification of the terrain, and may ...