Item: Snow depth measurements in avalanche starting zones
Title: Snow depth measurements in avalanche starting zones
Proceedings: Proceedings of the 2000 International Snow Science Workshop, October 1-6, Big Sky, Montana
Authors: Magnus Mar Magnusso, Jon Gunnar Egilsson and Oddur Petursson ICELANDIC METEOROLOGICAL OFFICE
Abstract: In the last few years, Iceland has started an extensive programme to build avalanche defense structuresfor threatened towns and villages. Part of those defense structures will be retaining structures in the starting zone. The design snow depth is a critical factor in designing such structures because they become much less effective jf they get buried. In order to evaluate this design snow depth, we have started a programme of measuring snow depth in avalanche starting zones. The programme consists of several different methods. First, we have Put snow stakes in the starting zones, which are read from down below, using theodolites several times throughout the winter. Also in late winter our snow observers go into the starting zones and measure snow depth along a profile, using avalanche probes. We have also experimented using a laser distometer to measure specific profilesin snow free conditions and then also during the winter. The difference will give us the snow depth. We have started experimenting taking aerial photographs of the starting zones in spring and having contour maps made of the snow surface and then using a geographical information system (GIS) to find the difference between the snow sUrface and the regular surface and thus obtaining the snow depth. In this paper we will give a description of the different methods, compare them and give examples of the results.
Keywords: avalanche starting zones, snow depth, snow mapping, acoustic depth sensors, laser distometers
Digital Abstract Not Available