Mapping Snow Cover Duration, Avalanches and Other Geomorphic Processes by Automatic Digital Cameras, Longyeardalen, Svalbard

A project funded by the University Courses on Svalbard (UNIS) 2000-2005

Ole Humlum, UNIS, Department of Geology, Svalbard, Norway

Background

Longyearbyen (10-100 m asl.) and the surrounding high ground (400-1000 m asl.) is exposed to significant snow drifting by SSE winds throughout most of the winter. Even though the annual precipitation is low, around 200 mm w.e., this causes a thick (1-4 m) snow cover to accumulate in lee-side locations, while no or only a thin snow cover is present at upwind sites. Very big snow drift forms (cornices) may form along the the down wind rim of extensive mountain plateaus, which act as source areas for drifting snow.

This redistribution of precipitation has significance for many phenomena. As one important example, snow drifting is presumably controlling the mass balance characteristics of many glaciers on Svalbard and many small glaciers face downwind (NNW) for that reason. 

On a more local scale, the thickness of the snow cover is important for ground temperatures due to the insulating effect, thereby influencing upon temperature and thickness of permafrost in the region. Also the plant cover is influenced by the thickness and duration of the snow cover, both during winter where the snow cover protects from physical wind abrasion and low temperatures, and during the growing season where surviving snow patches act as water reservoirs. For that reason, the most prominent vegetation is often found shortly downstream in relation to snow patches. Finally, the accumulation of big cornices along downwind mountain rims may represent a potential avalanche hazard for installations in the valley bottom below.

Manual mapping of the changing snow cover is difficult and requires a lot of manpower. During wintertime manual mapping will often be highly dangerous on steep slopes (avalanches). Therefore automatic digital cameras have been installed at four  different sites in the mountains around Longyearbyen. Each of these cameras obtain a scene once a day at solar noon and may operate without service for more than a full year. Power supply is ensured by high-capacity batteries supplemented by solar panels. The concept has previously been applied successfully in NE Greenland (Zackenberg; 74^oN)) and has capacity to survive both low temperatures and several months of winter darkness.

The camera (see illustration above) was developed by technician Ulf Thomas, assisted by Paul Christiansen, both at the Department of Geography, University of Copenhagen. 

From February 2002 it is possible to order the camera from the firm MetSupport. Click here for further information.

Based on such digital visual observations a mapping of wind-induced snow redistribution will be possible and will be correlated with meteorological data from the Auroral Station in Adventdalen and a number of small meteorological stations installed at various sites in the landscape around Longyearbyen. Also a mapping of the snow cover duration in various parts of the landscape will be easy to obtain from these visual data sets. This will provide visual data for estimating concepts as modern snow avalanche activity, mass balance on glaciers and the importance of snow accumulation for rock glacier activity.

Many other types of geomorphic events (snow avalanches, mudflows, landslides, etc.) will be recorded by the cameras. Of special interest will be the possibility of monitoring long-term variations of vegetation and the maximum snowline on glaciers (Larsbreen and Longyearbreen). 

The digital photos will be stored in a database at UNIS and  may represent a valuable source for later investigations within a broad range of subjects (geography, biology, etc.). Of immediate use will be the potential as a test facility for various computer modeled terrain activity.

Click on one of the 6 small pictures below in order to see a series of selected exposures obtained by the camera chosen. All exposures shown are reduced significantly as to resolution and is not representative for the high number of details visible in the original photos. All photos are taken at maximum daylight (at solar noon). 

    CAM11: Longyearbyen and lower Adventvalley; latest update 11. August 2003.

   CAM12+23: Longyearbreen; latest update 11. August 2003.

CAM19: Larsbreen; latest update 11. August 2003.

CAM20: Vandledningsfirnen; latest update 11. August 2003.

If you want to see what the meteorological conditions are like in the area around Longyearbyen, please click here.

Latest update: 3. January 2006.