Geomorphic evidence for present-day snow-avalanche and debris-flow impact in the Icelandic Westfjords

Decaulne, Armelle; Sæmundsson, Þorsteinn

doi:10.1016/j.geomorph.2005.09.007

Cited by 69 publications

(46 citation statements)

References 32 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Albeit these seem to cover the vast majority of the observed avalanche events here (see also e.g. Decaulne and Saemundsson, 2006), and are in widespread use in practice to model avalanche occurrence for long-term simulation, model tuning, and hazard evaluation (Salm et al, 1990;Burkard and Salm, 1992;Bartelt et al, 1999;Ancey et al, 2004;Barbolini et al, 2004), different triggering mechanisms can be observed. These include more frequent wet avalanches, or less frequent (T < 40 years or so) slush avalanches, including mud flows, both usually occurring at spring thaw (May to June, see e.g.…”

Section: Discussionmentioning

confidence: 98%

“…Preliminary analysis (reported in Bocchiola and Medagliani, 2007) showed that for 68% of the observed avalanches the triggering factor was linked to heavy precipitation in the 72 hours preceding the event (similar to e.g. Decaulne and Saemundsson, 2006). Therefore, it seems reasonable to investigate the probability of release as connected to the three day snowfall depth, H 72d .…”

Section: Probability Of Releasementioning

confidence: 99%

“…De Scally and Owens, 2005), sorting in the flowing and deposition area (e.g. Luckman, 1977;Gardner, 1983;Schaerer, 1988;Bell et al, 1990;Blikra and Saemundson, 1998;Heckmann et al, 2002;Decaulne and Saemundsson, 2006), and also soil chemical composition (e.g. Freppaz et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Use of a Regional Approach for Long-Term Simulation of Snow Avalanche Regime: a Case Study in the Italian Alps

Bocchiola

Medagliani

Rosso

2009

Arctic, Antarctic, and Alpine Research

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 98%

Section: Probability Of Releasementioning

confidence: 99%

See 1 more Smart Citation

Use of a Regional Approach for Long-Term Simulation of Snow Avalanche Regime: a Case Study in the Italian Alps

Bocchiola

Medagliani

Rosso

2009

Arctic, Antarctic, and Alpine Research

View full text Add to dashboard Cite

“…In the track, the presence of perched boulders reveals the geomorphic activity of snow avalanches. In the deposition zone, boulders transported by snow avalanches plough or not the slope surface and accumulate, being a clear indication of the snow-avalanche activity [5]. Several of these accumulations can be observed above settlements.…”

Section: Figurementioning

confidence: 99%

“On-zone” and “off-zone” geomorphic features for multirisk assessment related to slope dynamics in the Icelandic fjords

Decaulne¹,

Saemundsson²

2006

WIT Transactions on Ecology and the Environment, Vol 91

View full text Add to dashboard Cite

Geomorphological studies are a useful tool for risk analysis in mountainous areas, as most of the vulnerable settlements are located within the deposit zones of various processes acting on slopes. Risk assessment related to slope dynamics in the Icelandic fjords, such as snow avalanches and debris flows, often consider the geomorphic characteristics "on-zone", i.e. in the slope above the inhabited area, from the starting zone to the first houses. However, most of the useful extreme runout distance features are no longer visible in built areas, as slope deposits have been removed from the residential areas during the building time, and later on. Indeed, these landforms are of great significance in risk analysis. Therefore, inquiries into "off-zone" geomorphic evidences, in unspoiled areas with similar lithologic, topographic and meteorologic conditions to inhabited surroundings, reveal the missing information "on-zone". Based on field investigations and using dendrogeomorphologic opportunities, it especially indicates the potential runout distance of slope dynamics that are lacking in built areas. Consequently, by transferring the data from unspoiled areas to inhabited areas, geomorphic investigations are an indicator for damage potential analysis in areas subjected to devastating multi-slope dynamics. Furthermore, the specific topography of the Icelandic fjords is prone to unexpected risk, such as local snow-avalanche induced tsunamis. This process has not yet been taken in account in risk analysis, originating "off-zone". However, it caused severe damages and loss of lives during the last century in the Icelandic fjords.

show abstract

“…The role of snow avalanches as transporters of sediment and biogeochemical constituents has been acknowledged and attested to (e.g. Luckman, 1977Luckman, , 1978Gardner, 1983;Ward, 1985;Nyberg, 1989;Decaulne and Saemundsson, 2006), but received comparatively scarce attention from a quantitative view. Hence, compared to other processes of hillslope mass wasting such as rockfalls or debris flows, little is known about the geomorphic and ecological impacts of snow avalanches (Fig.…”

Section: Introductionmentioning

confidence: 99%

Soil erosion and organic carbon export by wet snow avalanches

Korup

Rixen²

2014

The Cryosphere

View full text Add to dashboard Cite

Abstract. Many mountain belts sustain prolonged snow cover for parts of the year, although enquiries into rates of erosion in these landscapes have focused almost exclusively on the snow-free periods. This raises the question of whether annual snow cover contributes significantly to modulating rates of erosion in high-relief terrain. In this context, the sudden release of snow avalanches is a frequent and potentially relevant process, judging from the physical damage to subalpine forest ecosystems, and the amount of debris contained in avalanche deposits. To quantitatively constrain this visual impression and to expand the sparse literature, we sampled sediment concentrations of n = 28 riverspanning snow-avalanche deposits (snow bridges) in the area around Davos, eastern Swiss Alps, and inferred an ordersof-magnitude variability in specific fine sediment and organic carbon yields (1.8 to 830 t km −2 yr −1 , and 0.04 to 131 t C km −2 yr −1 , respectively). A Monte Carlo simulation demonstrates that, with a minimum of free parameters, such variability is inherent to the geometric scaling used for computing specific yields. Moreover, the widely applied method of linearly extrapolating plot scale sample data may be prone to substantial under-or overestimates. A comparison of our inferred yields with previously published work demonstrates the relevance of wet snow avalanches as prominent agents of soil erosion and transporters of biogeochemical constituents to mountain rivers. Given that a number of snow bridges persisted below the insulating debris cover well into the summer months, snow-avalanche deposits also contribute to regulating in-channel sediment and organic debris storage on seasonal timescales. Finally, our results underline the potential shortcomings of neglecting erosional processes in the winter and spring months in mountainous terrain subjected to prominent snow cover.

show abstract

Geomorphic evidence for present-day snow-avalanche and debris-flow impact in the Icelandic Westfjords

Cited by 69 publications

References 32 publications

Use of a Regional Approach for Long-Term Simulation of Snow Avalanche Regime: a Case Study in the Italian Alps

Use of a Regional Approach for Long-Term Simulation of Snow Avalanche Regime: a Case Study in the Italian Alps

“On-zone” and “off-zone” geomorphic features for multirisk assessment related to slope dynamics in the Icelandic fjords

Soil erosion and organic carbon export by wet snow avalanches

Contact Info

Product

Resources

About