Multi-method (14 C, 36 Cl, 234 U/230 Th) age bracketing of the Tschirgant rock avalanche (Eastern Alps): implications for absolute dating of catastrophic mass-wasting

2016 ◽  
Vol 42 (7) ◽  
pp. 1110-1118 ◽  
Author(s):  
Marc Ostermann ◽  
Susan Ivy-Ochs ◽  
Diethard Sanders ◽  
Christoph Prager
Keyword(s):  
Rock Avalanche ◽  
Eastern Alps ◽  
Mass Wasting ◽  
Absolute Dating

scholarly journals Slope Failure in a Period of Increased Landslide Activity: Sennwald Rock Avalanche, Switzerland

Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 331
Author(s):  
Selçuk Aksay ◽  
Susan Ivy-Ochs ◽  
Kristina Hippe ◽  
Lorenz Grämiger ◽  
Christof Vockenhuber
Keyword(s):  
Slope Failure ◽  
Rock Avalanche ◽  
Eastern Alps ◽  
Rock Failure ◽  
Rhine River ◽  
Stratigraphic Sequence ◽  
Exposure Age ◽  
Wet Climate ◽  
Cosmogenic Nuclide Dating ◽  
Additional Support

The Säntis nappe is a complex fold-and-thrust structure in eastern Switzerland, consisting of numerous tectonic discontinuities and a range of hillslopes prone to landsliding and large slope failures that modify the topography irreversibly. A slope failure, namely the Sennwald rock avalanche, occurred in the southeast wall of this fold-and-thrust structure due to the rock failure of Lower Cretaceous Helvetic limestones along the Rhine River valley. In this research, this palaeolandslide is examined in a multidisciplinary approach for the first time with detection and mapping of avalanche deposits, dynamic run-out modelling and cosmogenic nuclide dating. During the rock failure, the avalanche deposits were transported down the hillslope in a spreading-deck fashion, roughly preserving the original stratigraphic sequence. The distribution of landslide deposits and surface exposure age of the rock failure support the hypothesis that the landslide was a single catastrophic event. The 36Cl surface exposure age of avalanche deposits indicates an age of 4.3 ± 0.5 ka. This time coincides with a notably wet climate period, noted as a conditioning factor for landslides across the Alps in the mid-Holocene. The contemporaneity of our event at its location in the Eastern Alps provide additional support for the contention of increased regional seismic activity in mid-Holocene.

scholarly journals Medieval age determined for the hitherto undescribed/undated rock avalanche of Münster (Inn valley, Eastern Alps)

Geomorphology ◽  
2021 ◽  
pp. 107802
Author(s):  
Diethard Sanders ◽  
Maximilian Wallner ◽  
Hannah Pomella
Keyword(s):  
Rock Avalanche ◽  
Eastern Alps

Extreme mass wasting during 2021 Dhauli Ganga event in the Higher Himalaya: insight from the landscape

2021 ◽  
Author(s):  
Anand Kumar Pandey ◽  
Kotluri Sravan Kumar ◽  
Virendra Mani Tiwari ◽  
Puranchand Rao ◽  
Kirsten Cook ◽  
...  
Keyword(s):  
Debris Flow ◽  
Extreme Event ◽  
Rock Avalanche ◽  
Slope Instability ◽  
Mass Wasting ◽  
Outburst Flood ◽  
Flood Warning ◽  
River Bed ◽  
High Flood ◽  
Glacial Lake Outburst Flood

<p>The slope instability and associated mass wasting are among the most efficient surface gradation processes in the bedrock terrain that produce dramatic landscape change and associated hazards. The wedge failure in periglacial Higher Himalaya terrain on 7th February in Chamoli, Uttarakhand (India) produced >1.5 km high rock avalanche, which amalgamated with the glacial debris on the frozen river bed produced massive debris flow along the high gradient Rishi Ganga catchment. The high-velocity debris flow and a surge of high flood led to extensive loss of life and infrastructures and issuing the extreme event flood warning along the Alakananda-Ganga river, despite there was no immediate extreme climatic event. The affected region is the locus of extreme mass wasting events associated with Glacial Lake Outburst Flood (GLOF) and Landslide Lake Outburst Flood (LLOF) in the recent past. We analyzed the landscape to understand its control on the 7th February 2021 Rishi Ganga event and briefly discuss other significant events in the adjoining region e.g. 1893/1970 Gohna Tal/Lake LLOF and 2013-Uttarakhand events in Chamoli, which have significance in understanding the surface processes in Higher Himalayan terrain.</p>

scholarly journals Created by the Monte Peron rock avalanche: Lago di Vedana (Dolomites, Italy) and its sediment record of landscape evolution after a mass wasting event

Landslides ◽  
2021 ◽  
Author(s):  
Bernd Zolitschka ◽  
Irene Sophie Polgar ◽  
Hermann Behling
Keyword(s):  
Little Ice Age ◽  
Rock Avalanche ◽  
Ice Age ◽  
Mass Wasting ◽  
Human Occupation ◽  
Cultural Changes ◽  
Sediment Stratigraphy ◽  
Artificial Opening ◽  
Eighteenth And Nineteenth Centuries ◽  
Lacustrine Ecosystem

AbstractThe timing of the Monte Peron Landslide is revised to 2890 cal. BP based on a radiocarbon-dated sediment stratigraphy of Lago di Vedana. This age fosters the importance of hydroclimatic triggers in the light of accelerating global warming with a predicted increase of precipitation enhancing the regional predisposition to large landslides. Moreover, a layer enriched in allochthonous organic and minerogenic detritus dating to the same wet period is interpreted as response to a younger and yet unidentified mass wasting event in the catchment of Lago di Vedana. Rock debris of the Monte Peron Landslide impounded the Cordevole River valley and created a landslide-dammed lake. Around AD 1150, eutrophication of this lacustrine ecosystem started with intensified human occupation – a process that ended 150 years later, when the river was diverted back into its original bed. Most likely, this occurred due to artificial opening of the river dam. In consequence, Lago di Vedana was isolated from an open and minerogenic to an endorheic and carbonaceous lacustrine system. After a monastery was established nearby in AD 1457, a second eutrophication process was initiated due to intensified land use linked with deforestation. Only in the eighteenth and nineteenth centuries, deposition of organic matter decreased coinciding with climatic (Little Ice Age) and cultural changes. Conversational measures are the likely reasons for a trend towards less eutrophic conditions since AD 1950.

scholarly journals Early late-glacial rock avalanche and its lasting effects on drainage and sediment dispersal (Strassberg valley catchment, Northern Calcareous Alps, Austria)

2018 ◽  
Vol 111 (2) ◽  
pp. 180-203
Author(s):  
Diethard Sanders ◽  
Hannah Pomella ◽  
Charlotte Gild
Keyword(s):  
Large Scale ◽  
Rock Avalanche ◽  
Late Glacial ◽  
Northern Calcareous Alps ◽  
Scale Morphology ◽  
Mass Wasting ◽  
Sediment Dispersal ◽  
Northern Calcareous ◽  
Last Glacial ◽  
Stream Incision

AbstractIn intramontane landscapes shaped by glacial-interglacial cycles, the most rapid changes during the proglacial/paraglacial phases may be amplified by catastrophic mass-wasting. Herein, we describe the Last Glacial Maximum (LGM) to Holocene development of a catchment in the Northern Calcareous Alps wherein intense proglacial/paraglacial sedimentation and descend of a rock avalanche persistently modified drainage and sediment dispersal.During buildup of the LGM, the pre-last glacial Strassberg valley – the trunk valley of this study – was filled with a proglacial fluvio-lacustrine succession. Thereafter, the area became largely buried under the Inn ice stream. During deglacial ice melt, copious sediment was shed from glacially-conditioned mountain flanks. Alluvial fans cut off from their former supply area, and perched in isolated position, result from presumed sediment dispersal across dead ice. Shortly after deglaciation, a ~11 Mm3 rock avalanche detached from a high cliff, overran an opposing mountain ridge, and spread over a lower-positioned plateau. The rock avalanche blocked the Strassberg valley and set the base-level to an intramontane basin that persists until present. A quartz OSL age from a loess drape above the rock-avalanche deposit dates mass wasting prior to 18.77 ± 1.55 ka; so far, this is the oldest age-bracketed post-LGM catastrophic mass-wasting of the Eastern Alps.After mass wasting, the valley was barred by the rock-avalanche deposit. This, in turn, triggered a westward switch of drainage thalweg and stream incision. The present Strassberg valley is an epigenetic bedrock gorge 1.5 km in length and down to 100 m in depth. A 234U/230Th calcite disequilibrium age of 9 ± 1 ka from cemented talus indicates that most incision took place during the late-glacial to early Holocene. Aside of the large-scale morphology (valleys, ranges) the drainage, the smaller-scale morphology, and the sediment volumes of the study area are mainly coined by proglacial/paraglacial processes and by rock avalanching. Holocene landscape changes are modest and chiefly comprise aggradation of high-positioned scree slopes, colluvial/alluvial redeposition and stream incision, and slope stabilization by reforestation. Our results underscore that intramontane sceneries are mosaics with respect to the age of landforms and that large parts of the landscape still are off geomorphic equilibrium with interglacial conditions.

Anatomy of a cascading hazard: the flood part of the 7 February Uttarakhand event

2021 ◽  
Author(s):  
Michael Dietze ◽  
Himangshu Paul ◽  
Anand Kumar Pandey ◽  
Rajesh Rekapalli ◽  
Puranchand Rao ◽  
...  
Keyword(s):  
Seismic Data ◽  
Slope Failure ◽  
Rock Avalanche ◽  
Physical Models ◽  
Data Sets ◽  
Mass Wasting ◽  
Spectral Signal ◽  
Seismic Networks ◽  
Kinetics Of ◽  
Initial Rock

<p>The 7 February Chamoli, Uttarakhand singularity imposed a severe geomorphic crisis. While remote sensing imagery quickly identified a major rock avalanche as its origin, there is a fundamental lack in high precision temporal information on the kinetics of this event about when, how, and why it evolved from a slope failure into a channel-confined mass wasting process, and ultimately into a debris laden flood. Furthermore, while the initial rock slide could be detected and located by global seismic networks, it was the flood which caused most of the destruction and fatalities. Yet, that part of the process cascade remained elusive in global seismic data sets.</p><p>Here, we present a detailed anatomy of the hazard cascade, with emphasis on the flood part. Using information from a dense seismic network, we explore the limits of detection and constrain its propagation velocity. By jointly inverting two physical models that predict spectral signal properties of floods, we estimate important hydraulic and sediment transport metrics. These information are key for designing any future early warning infrastructure.</p>

scholarly journals Created by the Monte Peron rock avalanche: Lago di Vedana (Dolomites, Italy) and its sediment record of landscape evolution after a mass wasting event

2021 ◽  
Author(s):  
Bernd Zolitschka ◽  
Irene Polgar ◽  
Hermann Behling
Keyword(s):  
Little Ice Age ◽  
Rock Avalanche ◽  
Ice Age ◽  
Mass Wasting ◽  
Sediment Record ◽  
Human Occupation ◽  
Cultural Changes ◽  
Sediment Stratigraphy ◽  
Artificial Opening ◽  
Lacustrine Ecosystem

The timing of the Monte Peron Landslide is revised to 2890 cal. BP based on a radiocarbon-dated sediment stratigraphy of Lago di Vedana. This age fosters the importance of hydroclimatic triggers in the light of accelerating global warming with a predicted increase of precipitation enhancing the regional predisposition to large landslides. Moreover, a layer enriched in allochthonous organic and minerogenic detritus dating to the same wet period is interpreted as response to a younger and yet unidentified mass wasting event in the catchment of Lago di Vedana. Rock debris of the Monte Peron Landslide impounded the Cordevole River valley and created a landslide-dammed lake. Around AD 1150, eutrophication of this lacustrine ecosystem started with intensified human occupation – a process that ended 150 years later, when the river was diverted back into its original bed. Most likely, this occurred due to artificial opening of the river dam. In consequence, Lago di Vedana was isolated from an open and minerogenic to an endorheic and carbonaceous lacustrine system. After a monastery was established nearby in AD 1457, a second eutrophication process was initiated due to intensified land use linked with deforestation. Only in the 18th and 19th century, deposition of organic matter decreased coinciding with climatic (Little Ice Age) and cultural changes. Conversational measures are the likely reasons for a trend towards less eutrophic conditions since AD 1950.

scholarly journals Discrimination of hot versus cold avalanche deposits: Implications for hazard assessment at Mount Meager, B.C.

2003 ◽  
Vol 3 (6) ◽  
pp. 713-724 ◽  
Author(s):  
M. L. Stewart ◽  
J. K. Russell ◽  
C. J. Hickson
Keyword(s):  
Risk Assessment ◽  
Volcanic Rock ◽  
Hazard Assessment ◽  
Rock Avalanche ◽  
Volcanic Edifice ◽  
Volcanic Complex ◽  
Critical Component ◽  
Mass Wasting ◽  
Lava Domes ◽  
Surficial Deposits

Abstract. The surficial deposits surrounding the Mount Meager volcanic complex include numerous avalanche deposits. These deposits share many attributes: (a) they are nearly monolithologic and comprise mainly intermediate volcanic rock clasts, (b) they lack internal structure, and (c) they are very poorly sorted. Despite these similarities, the avalanche deposits represent two distinct processes. Mass wasting of the Mount Meager volcanic edifice has produced cold rock avalanche deposits, whereas gravitational collapse of active lava domes and flows has produced hot block and ash avalanche deposits. The ability to discriminate between these "hot" and "cold" avalanche deposits is a critical component in the assessment of hazards in volcanic terranes. Hot block and ash avalanche deposits can be distinguished by the presence of radially-oriented joints, breadcrust textures, and incipient welding, which are features indicative of high emplacement temperatures. Conversely, rock avalanche deposits resulting from mass wasting events may be distinguished by the presence of clasts that preserve pre-depositional weathering and jointing surfaces. Volcanic avalanches are mechanically similar to rock avalanches but pose a greater hazard due to high temperatures, increased fluidization from degassing and the potential to decouple highly mobile elutriated ash clouds. The increasing use of hazardous regions such as the Lillooet River valley requires more reliable risk assessment in order to minimize losses from future hazardous events.

Momentum transfer and friction in the debris of rock avalanches

1989 ◽  
Vol 26 (4) ◽  
pp. 623-628 ◽  
Author(s):  
W. Van Gassen ◽  
D. M. Cruden
Keyword(s):  
Momentum Transfer ◽  
Sliding Friction ◽  
Rock Avalanche ◽  
Initial Position ◽  
Mass Wasting ◽  
Accurate Calculation ◽  
Frictional Material ◽  
Runout Distance ◽  
Debris Accumulation ◽  
Centre Of Gravity

When a mass of loose, dry, purely frictional material slides down an incline after release at a given velocity, the runout (the distance the centre of gravity of the displaced mass moves from its initial position) depends on momentum transfer within the mass. This can be estimated from the profile of the debris accumulation, which also allows more accurate calculation of apparent angles of sliding friction in rockfall avalanches. The apparent extreme mobility of the Elm and Frank slides, typical rockfall avalanches, is explained by momentum transfer in a loose, dry, purely frictional material with an angle of friction of 30°. Key words: mass wasting, momentum transfer, landslide, accumulation, rock avalanche, runout distance.

scholarly journals Early Holocene (8.6ka) rock avalanche deposits, Obernberg valley (Eastern Alps): Landform interpretation and kinematics of rapid mass movement

Geomorphology ◽  
2012 ◽  
Vol 171-172 ◽  
pp. 83-93 ◽  
Author(s):  
Marc Ostermann ◽  
Diethard Sanders ◽  
Susan Ivy-Ochs ◽  
Vasily Alfimov ◽  
Manfred Rockenschaub ◽  
...  
Keyword(s):  
Mass Movement ◽  
Rock Avalanche ◽  
Eastern Alps ◽  
Early Holocene ◽  
Rapid Mass
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