Slope failures and erosion rates on a glacierized high-mountain face under climatic changes

2013 ◽  
Vol 38 (8) ◽  
pp. 836-846 ◽  
Author(s):  
Luzia Fischer ◽  
Christian Huggel ◽  
Andreas Kääb ◽  
Wilfried Haeberli
Keyword(s):  
Climatic Changes ◽  
High Mountain ◽  
Slope Failures ◽  
Erosion Rates

scholarly journals Steady erosion rates in the Himalayas through late Cenozoic climatic changes

2020 ◽  
Vol 13 (6) ◽  
pp. 448-452 ◽  
Author(s):  
Sebastien J. P. Lenard ◽  
Jérôme Lavé ◽  
Christian France-Lanord ◽  
Georges Aumaître ◽  
Didier L. Bourlès ◽  
...  
Keyword(s):  
Climatic Changes ◽  
Late Cenozoic ◽  
Erosion Rates

scholarly journals On the influence of topographic, geological and cryospheric factors on rock avalanches and rockfalls in high-mountain areas

2012 ◽  
Vol 12 (1) ◽  
pp. 241-254 ◽  
Author(s):  
L. Fischer ◽  
R. S. Purves ◽  
C. Huggel ◽  
J. Noetzli ◽  
W. Haeberli
Keyword(s):  
Slope Failure ◽  
Temporal Distribution ◽  
High Mountain ◽  
European Alps ◽  
Permafrost Degradation ◽  
Slope Failures ◽  
Mountain Areas ◽  
Investigation Area ◽  
Rock Avalanches ◽  
Slope Instabilities

Abstract. The ongoing debate about the effects of changes in the high-mountain cryosphere on rockfalls and rock avalanches suggests a need for more knowledge about characteristics and distribution of recent rock-slope instabilities. This paper investigates 56 sites with slope failures between 1900 and 2007 in the central European Alps with respect to their geological and topographical settings and zones of possible permafrost degradation and glacial recession. Analyses of the temporal distribution show an increase in frequency within the last decades. A large proportion of the slope failures (60%) originated from a relatively small area above 3000 m a.s.l. (i.e. 10% of the entire investigation area). This increased proportion of detachment zones above 3000 m a.s.l. is postulated to be a result of a combination of factors, namely a larger proportion of high slope angles, high periglacial weathering due to recent glacier retreat (almost half of the slope failures having occurred in areas with recent deglaciation), and widespread permafrost occurrence. The lithological setting appears to influence volume rather than frequency of a slope failure. However, our analyses show that not only the changes in cryosphere, but also other factors which remain constant over long periods play an important role in slope failures.

scholarly journals Last-glacial-cycle glacier erosion potential in the Alps

2021 ◽  
Vol 9 (4) ◽  
pp. 923-935
Author(s):  
Julien Seguinot ◽  
Ian Delaney
Keyword(s):  
Climatic Conditions ◽  
High Mountain ◽  
Glacial Cycle ◽  
Glacier Surface ◽  
Climate History ◽  
Last Glacial ◽  
Erosion Rates ◽  
Erosion Processes ◽  
The Alps ◽  
The Last Glacial

Abstract. The glacial landscape of the Alps has fascinated generations of explorers, artists, mountaineers, and scientists with its diversity, including erosional features of all scales from high-mountain cirques to steep glacial valleys and large overdeepened basins. Using previous glacier modelling results and empirical inferences of bedrock erosion under modern glaciers, we compute a distribution of potential glacier erosion in the Alps over the last glacial cycle from 120 000 years ago to the present. Despite large uncertainties pertaining to the climate history of the Alps and unconstrained glacier erosion processes, the resulting modelled patterns of glacier erosion include persistent features. The cumulative imprint of the last glacial cycle shows a very strong localization of erosion potential with local maxima at the mouths of major Alpine valleys and some other upstream sections where glaciers are modelled to have flowed with the highest velocity. The potential erosion rates vary significantly through the glacial cycle but show paradoxically little relation to the total glacier volume. Phases of glacier advance and maximum extension see a localization of rapid potential erosion rates at low elevation, while glacier erosion at higher elevation is modelled to date from phases of less extensive glaciation. The modelled erosion rates peak during deglaciation phases, when frontal retreat results in steeper glacier surface slopes, implying that climatic conditions that result in rapid glacier erosion might be quite transient and specific. Our results depict the Alpine glacier erosion landscape as a time-transgressive patchwork, with different parts of the range corresponding to different glaciation stages and time periods.

The rise of high mountain peaks: Feedbacks between orographic precipitation, fluvial erosion and flexural isostasy

2020 ◽  
Author(s):  
Jörg Robl ◽  
Stefan Hergarten
Keyword(s):  
Windward Side ◽  
Leeward Side ◽  
Orographic Precipitation ◽  
High Mountain ◽  
Precipitation Pattern ◽  
Fluvial Erosion ◽  
Erosion Rates ◽  
Erosional Unloading ◽  
Orogenic Plateaus ◽  
Valley Incision

<p>The majority of the highest mountain peaks on Earth is located at the dissected rim of large orogenic plateaus such as the Tibetan Plateau or the Altiplano. The striking spatial coexistence of deep, incised valleys and extraordinary high peaks located at the interfluves led to the idea of a common formation even a hundred years ago: focused erosion in valleys triggers the rise of mountain peaks due to erosional unloading and isostatically driven uplift. Ridgelines rise at the interfluves parallel to major rivers, but an additional ridgeline forms perpendicular to the principal flow direction separating the dissected rim from the undissected center of the plateau. As major rivers originate within the plateau and bypass the highest peaks, the latter rigdeline does not form a principal drainage divide. However, it forms a strong orographic barrier with wet conditions at the windward and dry conditions towards the plateau center at the leeward side. The height of the ridgeline is controlled by valley incision via erosional unloading and isostatic uplift.  If the precipitation pattern responsible for localized valley incision is controlled by the geometry of orographic barriers, a series of complex feedbacks between precipitation, erosion and ridgeline uplift (including the evolution of the highest peaks) occurs.</p><p>In this study, we present first results of a novel numerical model, which couples (a) fluvial erosion based on the stream power law, (b) flexural isostasy including viscous relaxation and (c) orographic precipitation based on the advection and diffusion of moisture and its reaction on topographic barriers. Originating from a simple model setup with a plateau in the center of the model domain and moisture transported along a predominant wind direction, we explore the co-formation of valleys and the rise of ridgelines including the growth of extraordinary high peaks. As the evolving topography controls the precipitation pattern, erosion rates are high at the wet windward side of the ridgeline, which parallels the plateau rim, while the leeward side towards the plateau center is characterized by low precipitation and very low erosion rates. As it prevents elevated low-relief areas from dissection, we suggest that this mechanism is a principal cause for the longevity of orogenic plateaus.</p>

scholarly journals Recent and future warm extreme events and high-mountain slope stability

2010 ◽  
Vol 368 (1919) ◽  
pp. 2435-2459 ◽  
Author(s):  
C. Huggel ◽  
N. Salzmann ◽  
S. Allen ◽  
J. Caplan-Auerbach ◽  
L. Fischer ◽  
...  
Keyword(s):  
Slope Stability ◽  
Climate Models ◽  
Swiss Alps ◽  
High Mountain ◽  
Temperature Pattern ◽  
European Alps ◽  
High Mountains ◽  
Slope Failures ◽  
Recent Climate ◽  
The Future

The number of large slope failures in some high-mountain regions such as the European Alps has increased during the past two to three decades. There is concern that recent climate change is driving this increase in slope failures, thus possibly further exacerbating the hazard in the future. Although the effects of a gradual temperature rise on glaciers and permafrost have been extensively studied, the impacts of short-term, unusually warm temperature increases on slope stability in high mountains remain largely unexplored. We describe several large slope failures in rock and ice in recent years in Alaska, New Zealand and the European Alps, and analyse weather patterns in the days and weeks before the failures. Although we did not find one general temperature pattern, all the failures were preceded by unusually warm periods; some happened immediately after temperatures suddenly dropped to freezing. We assessed the frequency of warm extremes in the future by analysing eight regional climate models from the recently completed European Union programme ENSEMBLES for the central Swiss Alps. The models show an increase in the higher frequency of high-temperature events for the period 2001–2050 compared with a 1951–2000 reference period. Warm events lasting 5, 10 and 30 days are projected to increase by about 1.5–4 times by 2050 and in some models by up to 10 times. Warm extremes can trigger large landslides in temperature-sensitive high mountains by enhancing the production of water by melt of snow and ice, and by rapid thaw. Although these processes reduce slope strength, they must be considered within the local geological, glaciological and topographic context of a slope.

scholarly journals Last glacial cycle glacier erosion potential in the Alps

2021 ◽  
Author(s):  
Julien Seguinot ◽  
Ian Delaney
Keyword(s):  
Climatic Conditions ◽  
High Mountain ◽  
Glacial Cycle ◽  
Glacier Surface ◽  
Climate History ◽  
Last Glacial ◽  
Erosion Rates ◽  
Erosion Processes ◽  
The Alps ◽  
The Last Glacial

Abstract. The glacial landscape of the Alps has fascinated generations of explorers, artists, mountaineers and scientists with its diversity, including erosional features of all scales from high-mountain cirques, to steep glacial valleys and large over-deepened basins. Using previous glacier modelling results, and empirical inferences of bedrock erosion under modern glaciers, we compute a distribution of potential glacier erosion in the Alps over the last glacial cycle from 120 000 years ago to the present. Despite large uncertainties pertaining to the climate history of the Alps and unconstrained glacier erosion processes, the resulting modelled patterns of glacier erosion include persistent features. The cumulative imprint of the last glacial cycle shows a very strong localization of glacier erosion with local maxima at the mouths of major Alpine valleys and some other upstream sections where glaciers are modelled to have flown with the highest velocity. The modelled erosion rates vary significantly through the glacial cycle, but show paradoxically little relation to the total glacier volume. Phases of glacier advance and maximum extension see a localization of rapid erosion rates at low elevation, while glacier erosion at higher elevation is modelled date from phases of less extensive glaciation. The modelled erosion rates peak during deglaciation phases, when frontal retreat results in steeper glacier surface slopes, implying that climatic conditions that result in rapid glacier erosion might be quite transient and specific. Our results depict the Alpine glacier erosion landscape as a time-transgressive patchwork, with different parts of the range corresponding to different glaciation stages and time periods.

scholarly journals Epic landslide erosion from mountain roads in Yunnan, China – challenges for sustainable development

2014 ◽  
Vol 14 (11) ◽  
pp. 3093-3104 ◽  
Author(s):  
R. C. Sidle ◽  
M. Ghestem ◽  
A. Stokes
Keyword(s):  
Slope Failures ◽  
Sediment Delivery ◽  
The Road ◽  
Erosion Rates ◽  
Construction Techniques ◽  
Road Development ◽  
On The Road ◽  
Steep Terrain ◽  
Cut Slopes ◽  
Trigger Mechanisms

Abstract. Expanding systems of mountain roads in developing countries have significantly increased the risk of landslides and sedimentation, and have created vulnerabilities for residents and aquatic resources. We measured landslide erosion along seven road segments in steep terrain in the upper Salween River basin, Yunnan, China and estimated sediment delivery to channels. Landslide erosion rates along the roads ranged from 2780 to 48 235 Mg ha−1 yr−1, the upper end of this range being the highest rate ever reported along mountain roads. The two roads with the highest landslide erosion (FG1 = 12 966 Mg ha−1 yr−1; DXD = 48 235 Mg ha−1 yr−1) had some of the highest sediment delivery rates to channels (about 80 and 86%, respectively). Overall, 3 times more landslides occurred along cut slopes compared to fill slopes, but fill slope failures had a combined mass > 1.3 times that of cut slope failures. Many small landslides occurred along road cuts, but these were often trapped on the road surface. Given the magnitude of the landslide problem and the lack of attention to this issue, a more sustainable approach for mountain road development is outlined based on an analysis of landslide susceptibility and how thresholds for landslide trigger mechanisms would be modified by road location and different construction techniques.

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