International Snow Science Workshop

HIGH ARCTIC AVALANCHE MONITORING IN MARITIME SVALBARD

Markus Eckerstorfer*, Ullrich Neumann, Hanne H. Christiansen Department of Geology, The University Centre in Svalbard, UNIS, N­9171 Longyearbyen, Norway

ABSTRACT: The arctic, high relief Svalbard landscape, largely without vegetation and with a continuous snow cover for large parts of the year, is very exposed to avalanches. Wide plateaus with 500 m deep valleys domi­ nate the geomorphology in central Svalbard, allowing extensive snow drifting. In a changing climate and with an increasing number of people traveling around the Svalbard landscape, there is increased focus on avalanches and their meteorological control. A significant part of a three year research project (CRYOSLOPE Svalbard) is the year around avalanche monitoring programme. The results of avalanche mapping, meteorological observations and snow pit studies are collected in a database accessible online. The collected data show, that avalanches are observed year around. During autumn and the polar night only a few take place. As the air temperature increases and the maximum amount of snow are present at the same time in spring, the peak avalanche season occurs. Avalanches triggered by cornice falls form the majority. The collected data forms the important first systematic knowledge about meteorological, to­ pographical and snowpack conditions, which trigger avalanches in Svalbard.

KEYWORDS: Avalanche monitoring and mapping, meteorological observations, high arctic avalanche climate, snowpit study

1. INTRODUCTION takes place, surrounding the main settlement Longyearbyen. Thus avalanche recording is given In the last 50 years a number of ava­ a special importance. lanches caused casualties, material and infrastruc­ To date, little research has been done on ture damage on Svalbard. More knowledge about avalanches in Svalbard. Andrè (1990a, 1990b) the mechanism of snow avalanches in a high arc­ focused on the geomorphologic effects of ava­ tic environment is of great interest to the communi­ lanches, the Norwegian Geotechnical Institute ties living on Svalbard. The increasing snow mo­ (NGI) focused on avalanche safety issues. Hum­ bile traffic takes place in mountainous terrain af­ lum (2002) evaluated avalanche risk by modeling fected by active slope processes. The total num­ wind and topography in the Longyeardalen area ber of rental days of snow mobiles per year more as avalanche building factors. Hestnes (2000) than doubled from 2000 in 1997 to 4500 in 2001 identified meteorological factors which cause ava­ (Unger, 2003). Community traffic is not included. lanches. Ellehauge (2003) first established a win­ Increasing temperature and more precipitation in ter­spring spatial avalanche observation. northern high latitudes predicted by global climate This paper gives an overview of the first models, (Houghton et al. 2001) make improved results from the 1.5 years of the Cryoslope project. knowledge of snow avalanches in high arctic envi­ The workflow, the main tasks and the field work ronments timely and important. Therefore the area are described. An accurate analysis of all three year research project “Cryoslope Svalbard” observed avalanche events and avalanche caus­ coordinated by the University Center in Svalbard ing factors will be carried out. A “high arctic ava­ focus the main scientific question on how cold lanche and snow climate” as an improvement to mountain slopes will respond to future projected the common snow climates, used in different ava­ climate changes on Svalbard. lanche studies (Tremper 2001, McClung 1993), is A main part of the project is a year round introduced. observation of snow avalanches within the area, where most of the tourist and community traffic 2. STUDY AREA AND CLIMATE * Corresponding author address: Markus Eckerstorfer, Department of Geology, The Univer­ The study area (~ 16.8 km²) is located sity Centre in Svalbard, UNIS, N­9171 Longyear­ around Longyearbyen at 78 N in the high arctic, byen, Norway; Tel: +47 79023346; email: containing the 70 km long observation round (so [email protected] called “little round”) (Fig. 1). Longyearbyen (2000

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inhabitants) is the largest of only a few settlements vegetation in the high relief landscape. The domi­ in the Svalbard archipelago, situated in the centre nant annual wind direction across the study area is of the main island Spitsbergen. The whole archi­ from SSE, local wind directions may vary (Hum­ pelago covers about 63 000 km², between 74 ­ lum, 2002). 81 N and 10 – 35 E. Due to its high latitude, the study area in Mountain massifs, intersected by wide val­ Svalbard is influenced by the polar night (26 Octo­ leys tending E­W dominate the area, reaching ber to 16 February) and midnight sun (19 April to more than 1000 m a.s.l. Many mountains display a 23 August) season, which cause large seasonal plateau­like summit form, controlled by horizontal variations in the amounts of incoming radiation. bedding of the sedimentary rocks. Alpine topogra­ phy can also be found in the area. About 60 % of Svalbard is glacier covered today. Glaciation is 3. METHODS limited to smaller 5 km long glaciers in the study area (Humlum, 2002). The Cryoslope project, studying modern Permafrost is continuous on Svalbard day slope processes, has three main parts. First (Humlum, 2003, et al.) and the thickness in the and most important is the year round observation study area is relatively well known from mining of high arctic mountain slope processes, their im­ operations, ranging from less than 100 m near the pact on traffic, and their potential response to cli­ coasts to more than 500 m in the higher parts. mate change, especially during the snow season. Permafrost affects the ground thermal regime and The second task is the maintenance and compila­ thus also the snowpack temperature. tion of an avalanche observation database. The Sea currents and air masses with different data is processed statistically, mapped in a GIS thermal characteristics heavily influence Svalbard and made accessible to the public on the project and affect the meteorology. The northernmost webpage (http://www.skred.svalbard.no), which margin of the North Atlantic Drift flows along the forms the third main task. During spring 2008, 60 west coast of Svalbard, while cold polar water field trips were carried out in 4 months, so obser­ flows south along the east coast. Another major vation every second day. One part of the study influence is the rapid variations in sea­ice extent, area follows the avalanche exposed Svalsat road which largely control changes in atmospheric cir­ up the plateau mountain west of Longyearbyen culation (Benestad, 2002, et al.) The meteorology (Fig. 1). The main round (50 % of our field trips) is well documented since 1911 (Førland, 1997, et. carried out by snow mobile, passes through six al.) in Longyearbyen. The coldest month is usually valleys, which are divided for the data analysis into February with an average air temperature of 8 parts (Fig. 1). The criteria for choosing this route ­15.2 C, the warmest July, with 6.2 C. The late were: 20 th ­century MAAT (mean annual air temperature) is ­5.8 C (average 1975­2000), but rising up to ­ The frequent traffic on the “little round” by tour­ ­5 C at the beginning of the 21 st century. (Met.no) ists and inhabitants makes safety perspectives Precipitation at sea level is only about 190 of this survey applicable for infrastructure mm water equivalent in Longyearbyen (Førland, planning and daily life activities. 1997, et. al.), but a significant vertical precipitation ­ The variety in elevation. The snow mobile gradient exists with more snow in higher altitudes. track mainly follows the valley bottoms, vary­ The periods February ­ March and August ­ Sep­ ing from 0 m a.s.l. to over 440 m a.s.l. tember are humid, April ­ May is relatively dry. No­ ­ Proximity to Longyearbyen, enables quick and vember ­ December may experience heavy snow­ frequent field access. fall as well as short­lived mild spells. However, all ­ A minimum of logistics and safety, although a seasonal phenomena are exposed to large inter­ full survival kit, rifle and signal pistol for polar annual variations. Therefore snow may fall at any bear protection and a satellite phone are man­ altitude and any time of the year, and forms the datory. During the polar night season, night vi­ dominant type of precipitation. At sea level, the sion equipment is used for slope observations. ground surface is usually snow covered from early ­ The landscape in this area provides both October to early June, higher altitudes tend to be sharp mountain peaks and ridges, as well as covered continuously by snow, except wind ex­ plateau mountains and valleys. posed peaks, slopes and plateaus. ­ The valleys tend N­S as well as E­W and are The wind largely influences the meteorol­ both wide and narrow in cross section. ogy in Svalbard with significant redistribution of snow due to its consistency and the lack of any tall

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­ The variety of slope aspects and slope inclina­ cate the longer snow period 2008. The high pres­ tions, thus being exposed to different wind di­ sure weather in March / April 2008, as well as the rections and solar radiation, causing different large amount of snow fall in the first week of May conditions in terms of avalanche formation. 2008, resulted in a longer constant snow cover, ­ Coastal as well as inland settings in the study causing a longer field investigation period and area in terms of meteorological and topog­ more avalanches in mid and late May. raphical factors. 4.2 Type and timing of avalanches Intensive field observation starts when Seven different types of avalanches as light conditions and better visibility increase traffic described in the Glossary Snow and Avalanches along the common snow mobile routes. When the (Working group European Avalanche Forecasting snow starts to melt in late spring, making it impos­ Service) were recorded. Besides the main com­ sible to drive around, the snow season field work mon type loose snow avalanches and slab ava­ ends. Only the easily accessible slopes in lanches we also distinguished between cornice fall Longyeardalen and above the Svalsat road are avalanches, cornice falls which triggered slabs or then studied. The following observations are done loose snow avalanches, rock falls and slushs. The in the field: data analyzed shows an equal distribution of loose snow avalanches, cornice falls and slabs. 93 % of ­ Avalanches: Type, size, shape, slope inclina­ all avalanches were naturally triggered, only 4 % tion, debris front position, geographical distri­ by snow mobiles and 3 % by skiers, snowboarders bution or climbers. ­ Meteorology: Precipitation, wind, temperature Ordering the different avalanche types and cloud cover. chronologically over the whole Cryoslope project ­ Snowpack observations: Layering, sintering, period gives a more detailed picture. Loose snow density and hardness from snow pit studies. avalanches rarely happen during the polar night ­ Snow stability: Relationship between season (1 in February 07, 3 in February 08), while downslope loads and the shear strength from in March 2007 their number increased to 30. In stability tests. 2008 this rush took place two months later, in ­ Hazard evaluation: Evaluation of the local ava­ May. These wet, loose snow avalanches started lanche danger by combination and considera­ triggering with ongoing saturation of the snow­ tion of meteorological and snowpack data, pack. Dry, loose avalanches usually form under avalanche data and photographs. windless conditions and therefore only rarely take place on Svalbard. Only little sluffs, triggered by The collected field data is stored in a da­ snow mobiles on steep slopes and small dry, tabase, presented in a GIS and published on the loose snow avalanches after dry snow showers in project webpage. All avalanches are stored with all winter, were observed. No clear monthly distribu­ observation parameters. Additional photographs tion of slab avalanches is found because of the show the extent and location, which is also visual­ requirement of a weak layer and a cohesive plate ized in an embedded “Google Maps” application. of snow. Therefore slabs depend much on differ­ ent meteorological situations, for example in May 2008 (­1.9 C average temperature), when a weak 4. RESULTS AND DISCUSSION layer of medium sized facets was built by diurnal recrystallization. Cornice falls happen year round The Cryoslope Svalbard project started in and were mostly observed after significant tem­ January 2007. The data presented in this paper perature rise in combination with strong winds, as was collected between this date and 5 June mark­ well as during the melting period. ing the end of the 2008 field season. The regional variations give a good un­ derstanding about both meteorological and topog­ 4.1 Number of avalanches raphical factors, which control avalanches. Toda­ During this first project period, 332 ava­ len and Longyeardalen, which have the most ava­ lanches were observed, recorded and analyzed lanche activity, are orientated NNE – SSW (Fig. (Fig. 1). In spring 2008 more avalanches were re­ 1). Therefore the prevailing wind from the SE built corded than in whole 2007, due to a longer snow large cornices, which collapsed and released other period with more frequent fieldwork. Most ava­ avalanches. Also more weak snow layers in the lanches occurred in May 2008 (79 avalanches), avalanche starting zones beneath the ridges of the March (67) and April (61) 2007, which also indi­ plateau shaped mountains were found. From the

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topographical point of view, Todalen and terrain, the smaller the avalanche debris size and Longyeardalen are both surrounded by similar volume are. Studying the average debris volume slopes. A sharp ridge line steeply drops down (in­ grouped by aspect shows, that the largest ava­ clination of between 50 and 60 ) and runs lanches happened between SW to NW as well as smoothly out to about 15 . 53 % of all avalanches between N to E. stop between 20 and 30 , 30 % between 10 and 20 , but almost 10 % run down to less than 10 4.5 Meteorological event analysis and put the snow mobile routes at high risk (Fig. Four different meteorological events 1). which, represent the snow season 2008 (January – June) have been identified (Fig. 2). The four 4.3 Aspect of avalanches events represent the maritime climate of Svalbard Avalanches take place in all aspects. Dif­ and its affects on snowpack layering, stability and ferences in the amounts are mainly influenced by increase of avalanche activity. These events are wind. This close relationship is underlined by the typical for a “high arctic snow climate”, which will fact that 22 % of all avalanches happen on slopes be further discussed in the conclusion. facing NW and only 11 % on SE facing slopes, due to the prevailing wind from SE. In every other 4.5.1 Winter warm spell event aspect (except NW and SE), the distribution is The maritime meteorology of Svalbard quite uniform around 15 %, only 5 % of all ava­ causes warm spells to happen every winter when lanches are observed on slopes facing north (Fig. low pressures bring warm air from S/SW. The last 1). Only slopes in Bødalen and at the Svalsat road three days of 2007 were constantly cold, with tem­ face north. This is underlined by a differentiation of peratures below ­20 C. The year 2008 started with the number of avalanches by aspect per valley. a very quick temperature rise up to +5.8 C at sea Particularly in Todalen, the valley with the longest level with 18 m/s maximum wind speed from W. N­S extension the wind influence is clear. Overall, On 3 January 11 mm of rain fell at sea level, the more than a third of all avalanches were triggered normal amount of precipitation in January is 15 on slopes facing NW and were classified as cor­ mm. On 4 January, the temperature suddenly nice fall avalanches. Loose snow avalanches dropped to ­14 C and rose again on 5 January, up mainly occurred on NNE (25 %) and SSW (25 %) to 1.5 C. facing slopes. Slab avalanches occurred on all The presence of rain and fluctuating tem­ aspects equally, with most being observed on SE peratures resulted in the formation of a rain curst to SW facing slopes. This may be an indicator of up to 10 cm thick. This crust was buried under a more rapid metamorphism in the snowpack during 20 cm snow layer on 21 January. Because of the springtime, as a result of solar radiation, as well as polar night with constant low temperatures, the constant cross loading by the prevailing wind. rain crust remained a long time in the snowpack and could be found in almost every valley, aspect 4.4 Volume of avalanches and height in the study area, until the end of April The three largest avalanches happened at when large temperature gradients formed it into a the end of March 2007 on Nordenskioldfjellet (Fig. layer of small facets (Fig. 2). 1). Two slabs and one cornice fall, which triggered The avalanche activity and ­danger did not a slab, were naturally triggered after heavy snow increase immediately following the warm weather falls. The weak layer was an up to 15 cm thick event at the beginning of January. It increased layer of depth hoar. The cornice fall/slab debris after the heavy snowfall with strong winds (max. covered an area of 150 000 m² with a volume of 17 m/s, SE) on 21, 28 and 29 January. The in­ 225 000 m³. crease in avalanche activity mainly involved cor­ The largest avalanches were mainly cor­ nice fall avalanches on lee­side slopes and some nice falls, which triggered both slabs and loose wind slabs, triggered on the rain crust. snow avalanches. The average debris area was about 870 m² the average debris volume about 4.5.2 Stable high pressure period 484 m³. The largest debris size was observed in During February / March / April 2008, Longyeardalen with almost 2400 m², followed by Svalbard was influenced by classic winter high the Larsbreen area with nearly 2200 m². These pressure weather with stable cold temperatures sites are located below of mountain plateaus on (average temp. at 460 m a.s.l. ­12.25 C) and a steep slopes, providing perfect conditions for cor­ prevailing wind from SSE with average wind nice falls. The largest avalanche debris are depos­ speeds of 5.3 m/s, ranging to a maximum of ited at 10­20 slope inclination, and the steeper the

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Figure 2: Typical snow pits representing the four meteorological events which characterize the February, some cornice falls triggered both slabs snow season 2008 (January – June). and loose snow avalanches, which contained mainly only the wind packed layers that sled down 20 m/s. The normal average precipitation rate in on the well bonded and hard snowpack. February / March is about 20 mm (Met.no). The largest amount of snow fell in two periods around 4.5.3 Spring warming event 17 February and 25 March, both times with high Large amounts of snow (30 cm of new wind speeds between 12 and 15 m/s and high snow) in the first week of May increased the ava­ temperatures around ­1.5 C. lanche danger due to the traffic in the study area The combination of snowfall and strong during this time. Temperatures were near the wind immediately packed the precipitating snow freezing point, the midnight sun in combination into a dense wind slab. During this high pressure with strong winds and the large amount of new period the snowpack changed very slowly. A snow triggered many avalanches. The average common snowpack mainly consisted of a 10­15 temperature in May was 4.8 C on Gruvefjell with a cm thick layer of depth hoar on the ground, a hard minimum of ­13 C. The stable high pressure which and dense layer of facets above and the ice layer dominated during March / April was replaced by from the beginning of January underneath equilib­ low pressure weather from the West. rium snow layers. On top fragmented snow or The 24 hour daylight and increasing tem­ highly broken particles were found. (Fig. 2). peratures had a large impact on the snowpack in The snowpack was mostly very hard, dry May. South facing slopes were more saturated in and cold, with a small temperature gradient and a the top layers with a large temperature gradient, common layering in different valleys, elevations resulting in rapid faceting. A sun crust was found and aspects. Weak layers such as the rain crust on slopes at all aspects. The warm snow surface, buried underneath a very hard and dense snow­ air temperature close to 0 C and a cold snowpack, pack were almost impossible to trigger by addi­ created a steep temperature gradient which tional load (Fig. 2). Several Compression Tests metamorphosed the top few centimeters into me­ showed (never under 25 hits) stable conditions dium sized facets (diurnal recrystallization) (Fig. during this period. The metamorphosis of the 2). This phenomenon became dangerous after snowpack happened slowly, therefore the different new snow fell on top of this weak layer, packed layers persisted for quite a long time. Differences and sled down on it. in the snowpack thickness were only found in the Most avalanche activity was observed snowpack height due to wind loading, mainly cross from mid May, primarily in the form of slabs and loading in flat areas and top loading on lee­side some loose snow avalanches, which were trig­ slopes. The avalanche activity mostly took place in gered by falling rocks or the ongoing increase in

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water content of the near surface snow layers. year round, but mainly in late winter and Many naturally triggered avalanches, as well as a spring. few slabs triggered by snow mobiles, occurred in c. Constant cold temperatures from high pres­ all aspects and elevations. This highlighted the sure weather with temperatures below ­25 C, unstable conditions, which were also observed in causing stable avalanche situation during several snow pit studied. spring. d. Strong redistribution of snow by wind as a 4.5.4 Melting period main factor for building of slabs. Between mid May and mid June, the av­ e. 24 hour solar radiation during the midnight sun erage air temperature increased to ­1.7 C at sea season resulting in a weak snowpack and an level, resulting in countless small, loose snow ava­ increasing wet, loose snow avalanche activity. lanches. From the second week of June, Svalbard faced strong winds, and some snow precipitation. 2. Topographical factors: At the beginning of summer, the weather is gener­ a. Large cornices along plateaus build up many ally unstable, with constant wind (mostly from W), cornice falls. often partly cloudy and with fluctuating air tem­ b. Avalanche run­out tends to be long due to the perature (around ­3 C to +5 C). lack of vegetation. The mild temperatures, in combination c. The field area contains both coastal and with the constant solar radiation, saturated the mountainous (up to 1000 m) locations, provid­ snowpack through to the ground, loss of strength ing differences in temperature, wind speed, and hardness could be observed, as well as an precipitation and therefore different avalanche isothermal snowpack without different layers (Fig. activity. 2). The large cornices on the plateau mountains which were growing during the entire winter and 3. Snowpack factors: remained because of the constant high pressure a. Existence of depth hoar as a persistent weak weather in early spring, finally began to melt. They layer. respectively released small amounts of snow b. Mostly identical, very hard and dense snow­ which triggered loose snow avalanches or they fell pack, therefore very stable conditions during down completely, causing deposition on the ava­ the polar night and early spring. lanche fens. c. Quick melting process through the whole The snow mobile season ended around snowpack in spring due to the midnight sun the end of May, thus the danger of triggering an and rising temperatures. avalanche was close to zero. Mainly loose snow avalanches which triggered down to the ground or The common snow climate classification sled down on the depth hoar, and cornice falls (McClung & Schaerer, 1993) does not suit the high could have potential avalanche dangers. These arctic environment on Svalbard very well. But avalanches often did not run far due to the rough identifying general characteristics and parameters surface and the small amount of snow left on the and classifying them into a snow climate, could be slopes. Rapid melting took place from the second used for designing appropriate avalanche safety week of June, mainly in the lower part of the land­ programs and climate change related avalanche scape. More cornice falls and slush avalanches models. Given the failure of the current snow cli­ were expected after this time. mate and avalanche climate classification in high arctic environments, we propose a new snow cli­ mate, the “high arctic snow climate” which con­ 5. CONCLUSION tains a “high arctic avalanche climate”. After Hae­ geli and McClung (2003), the “avalanche climate” The first systematic observations show the is an adjunct to the description of the “snow cli­ following characteristics: mate” in an area, in our case the area around Longyearbyen in central Spitsbergen, which 1. Meteorological factors: represents high arctic mountain climates. The a. Little precipitation, therefore only thin and “high arctic avalanche climate” contains some weak snowpacks with high temperature gradi­ “continental snow climate” parameters but is heav­ ents in the midsummer period. ily maritime and influenced by the high latitude: b. Storms can bring snowfall also during the summer time, therefore avalanches can occur ­ Thin snowpack (between 0.5 and 3.5 meters).

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­ Cold temperatures (­15 C to ­35 C) during the Førland, E.J., Hanssen­Bauer, I., Nordli, P.Ø., polar night with warm spells. 1997. Climate Statistics and Long­term Series of ­ Very dry precipitation snow. Temperature and Precipitation at Svalbard and ­ Common weak layers, like depth hoar, are Jan Mayen. Det Norske Meteorologiske Institutt, very persistent through time. Oslo, Klima report No. 21/97. 72pp. ­ Very hard and dense snowpack, therefore Haegeli, P., McClung, D. M., 2003. Avalanche stable for most of the winter. characteristics of a transitional snow climate – Co­ ­ Snow avalanches can occur during the whole lumbia Mountains, British Columbia, Canada. Cold year. Regions Science and Technology 37. 2003. 255­ ­ Slush avalanches can occur all over on slopes 276. with less than 10 degrees inclination. ­ The change from the stable high pressure Hestnes, E., 2000. Impact of rapid mass move­ spring to the midnightsun period causes most ment and drifting snow on the infrastructure and of the avalanches. development of Longyearbyen, Svalbard. Interna­ ­ Many avalanches occur as direct response to tional Workshop on Permafrost Engineering. precipitation and wind. Longyearbyen, Svalbard 2000. Proceedings. 259­ ­ Stability evaluation involves all factors: 282. weather, avalanche activity, snowpit study, Houghton, J.T., Ding, Y., Griggs, D.J., Noguer, M., stability tests, and surface clues. van der Linden, P.J., Dai, X., Maskell, K. and Johnson, C.A., 2001. Climate Change 2001: The More detailed data collection, of ava­ Scientific Basis. Contribution of Working Group 1 lanche observation and snowpack parameters as to the Third Assessment Report of the Intergov­ well as avalanche path visualization, will be car­ ernmental Panel on Climate change. Cambridge ried out in the second 1.5 years of the Cryoslope University Press. 881 pp. Svalbard project. Humlum, O., 2002. Modeling late 20 th ­century pre­ cipitation in Nordenskiold Land, Svalbard, by 6. ACKNOWLEDGEMENTS geomorphic means. Norsk Geografisk Tidsskrift – The Cryoslope Svalbard project is funded by the Norwegian Journal of Geography. 56:2. 96­103. Research Council of Norway (2007­2009). Thanks Humlum, O., Instanes, A., Sollid, J.L., 2003. Per­ to all colleagues and Longyearbyen inhabitants mafrost in Svalbard: a review of research history, informing us about avalanches in our study area. climatic background and engineering challenges. Polar Research 22(2). 191­215. 7. REFERENCES: Met.no, http://www.yr.no/sted/Norge/Svalbard/Longyearby André, M.­F., 1990a. Frequency of debris flows en/statistikk.html and slush avalanches in Spitsbergen: a tentative McClung, D.M., Schaerer, P., 1993. The Ava­ evaluation from lichenometry. Polish PolarRe­ lanche Handbook. The Mountaineers, Seattle, search. 11. 345­363. WA, 272 pp. André, M.­F., 1990b. Geomorphic impact of spring Tremper, B., 2001. Staying alive in avalanche ter­ avalanches in northwest Spitsbergen (79°N). Per­ rain. The Mountaineers, Seattle, WA. 284 pp. mafrost and Periglacial Processes. 1, 97­110. Benestad, R.E., Hanssen­Bauer, I., Skaugen, Unger, S., 2003. Wilderness Management on T.E., Førland, E.J., 2002. Associations between Svalbard – Recent Concepts, Future Options, and Sea­ice and the Local Climate on Svalbard. Nor­ Social Consequences. Diploma thesis. Unis. wegian Meteorological Institute Report No.07/02. 144pp. 1–7. Working group European Avalanche Forecasting Ellehauge, J., 2003. Influence of meteorological Service, Glossary Snow and Avalanches, and topographic conditions on snow avalanches n http://www.avalanches.org central Spitsbergen, Svalbard. Master thesis. UNIS. 65 pp.

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