The Kandersteg rock avalanche (Switzerland): integrated analysis of a late Holocene catastrophic event

Singeisen, Corinne; Ivy‐Ochs, Susan; Wolter, Andrea; Steinemann, Olivia; Akçar, Naki; Yeșilyurt, Serdar; Vockenhuber, Christof

doi:10.1007/s10346-020-01365-y

Cited by 20 publications

(26 citation statements)

References 82 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From this crosscutting relationship and the oldest and lowermost (minimum) formation age atop its front of 8.9 ka (Err1), it follows that these lobes must have formed after the Egesen cirque glacier starvation during the late Younger Dryas (Frauenfelder et al, 2001;Kerschner and Ivy-Ochs, 2008;Ivy-Ochs et al, 2009;. After 10 ka, the climate shifted towards warmer conditions (Schimmelpfennig et al, 2014;Solomina et al, 2015). Already by the Middle Holocene, the lower continuous permafrost boundary rose to likely above 2600 m a.s.l.…”

Section: Episodic Formationmentioning

confidence: 94%

Deciphering the evolution of the Bleis Marscha rock glacier (Val d'Err, eastern Switzerland) with cosmogenic nuclide exposure dating, aerial image correlation, and finite element modeling

et al. 2021

Self Cite

View full text Add to dashboard Cite

Abstract. We constrain the Holocene development of the active Bleis Marscha rock glacier (Err–Julier area, eastern Swiss Alps) with 15 cosmogenic nuclide exposure ages (10Be, 36Cl), horizontal surface creep rate quantification by correlating two orthophotos from 2003 and 2012, and finite element modeling. We used the latter to separate the control on surface movement exerted by topography and material properties. Bleis Marscha is a stack of three overriding lobes whose formation phases are separated by time gaps expressed morphologically as over-steepened terrain steps and kinematically as a sharp downslope decrease in surface movement. The three discrete formation phases appear to be correlated to major Holocene climate shifts: Early Holocene low-elevation lobes (∼8.9–8.0 ka, after the Younger Dryas), Middle Holocene lobe (∼5.2–4.8 ka, after the Middle Holocene warm period), and Late Holocene high-elevation lobes (active since ∼2.8 ka, intermittently coexisting with oscillating Bleis Marscha cirque glacierets). The formation phases appear to be controlled in the source area by the climate-sensitive accumulation of an ice-debris mixture in proportions susceptible to rock glacier creep. The ongoing cohesive movement of the older generations requires ice at a depth which is possibly as old as its Early–Middle Holocene debris mantle. Permafrost degradation is attenuated by “thermal filtering” of the coarse debris boulder mantle and implies that the dynamics of the Bleis Marscha lobes that once formed persisted over millennia are less sensitive to climate. The cosmogenic radionuclide inventories of boulders on a moving rock glacier ideally record time since deposition on the rock glacier root but are stochastically altered by boulder instabilities and erosional processes. This work contributes to deciphering the long-term development and the past to quasi-present climate sensitivity of rock glaciers.

show abstract

Section: Episodic Formationmentioning

confidence: 94%

Deciphering the evolution of the Bleis Marscha rock glacier (Val d'Err, eastern Switzerland) with cosmogenic nuclide exposure dating, aerial image correlation, and finite element modeling

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…A long time has passed since surface advection came to a halt, and the travel time is within the uncertainty of the exposure age. The exposure ages are rather inactivity or stabilisation ages than travel time estimates, as previously reported (Moran et al, 2016;Steinemann et al, 2020).…”

Section: Surface Kinematics Across Time Scalesmentioning

confidence: 76%

“…Frauenfelder et al (2001) indicate that the lower permafrost boundary was depressed several hundred meters more than the glacier equilibrium line altitude (ELA), opening a wide periglacial altitude belt (cf. Steinemann et al, 2020). This dry-cold permafrost phase lasted from late YD until about 10 ka.…”

Section: Early Holocene: Rapid Debris-conditioned Growthmentioning

confidence: 97%

“…Boulders at the rock glacier surface suitable for exposure dating were sampled with hammer, chisel, and battery-powered saw according to guidelines of Ivy-Ochs and Kober (2008) and field observations. The samples (~0.5 kg of rock material each) were collected along the central flow line from the lowermost front up to the high-elevation active lobes, preferentially on ridges to minimise topographic and snow shielding (Böhlert et al, 2011b) and towards the frontal upper edge of each morphologically identified lobe (Haeberli et al, 2003;Steinemann et al, 2020). 14 samples were Julier granodiorite (quartz, 10 Be; Table 1); only one dolomite boulder for 36 Cl met the sampling criteria (Table 2).…”

Section: Be and 36 CL Exposure Datingmentioning

confidence: 99%

See 1 more Smart Citation

Deciphering the evolution of the Bleis Marscha rock glacier (Val d'Err, eastern Switzerland) with cosmogenic nuclide exposure dating, aerial image correlation, and finite-element modelling

Amschwand¹,

Ivy‐Ochs²,

Frehner³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract. We constrain the Holocene morphodynamic development of the Bleis Marscha rock glacier (Err-Julier area, eastern Swiss Alps) with fifteen cosmogenic nuclide exposure ages (10Be, 36Cl), 2003/2012 horizontal surface creep rate quantification from orthophoto orientation correlation, and semi-quantitative ice-content estimates from finite-element modelling. The results suggest that the complex Bleis Marscha rock glacier formed during two activity phases, one in the early Holocene and one in the late Holocene, separated by a mid-Holocene period of inactivation. The now transitional-inactive low-elevation lobes (first generation) formed after the retreat of the Egesen cirque glacier in a pulse-like manner at 11.5–9.0 ka. Rock-glacier viscosities inverted with the finite-element model hint at ground ice in these lobes which is possibly as old as its early-Holocene debris cover. In contrast to the debris-conditioned rapid emplacement, the thermally controlled permafrost degradation is still ongoing, likely attenuated by thermal decoupling from the insulating coarse-debris boulder mantle. Nuclide loss from boulder erosion, affecting the nuclide inventory of boulders independently, led to a heterogeneous exposure age distribution on the transitional-inactive lobes. Exposure ages on such disturbed lobes record time elapsed since inactivation and are interpreted as (minimum) stabilisation ages. The inception of the active high-elevation lobes (second generation) at 2.8 ka is related to the late-Holocene cooling recorded at numerous sites across the Alps. Precise exposure ages of the last 1.2 ka correlate with down-stream distance and yield a long-term average surface speed coincident with 2003/2012 measurements. These long-term consistent surface creep rates indicate stable permafrost conditions and continuous rock-glacier growth despite the intermittent late-Holocene glacier cover of the Bleis Marscha cirque. The exposure ages on active, undisturbed lobes record time elapsed since boulder emergence at the rock-glacier root and are interpreted as travel time estimates. This work contributes to deciphering the past to quasi-present climate sensitivity of rock glaciers.

show abstract

“…Large bedrock landslides represent an important geomorphological process in terms of the evolution of hillslopes and fluvial and glacial systems in mountainous terrains around the world (Densmore and Hovius, 2000;Korup, 2002;Korup et al, 2005;Hewitt et al, 2008;Ivy-Ochs et al, 2009;Shulmeister et al, 2009;Davies and McSaveney, 2012;Deline et al, 2015;Crosta et al, 2017;Singeisen et al, 2020). Substantial rock-slope failures are frequently observed in mountain landscapes due to the high topographic relief and hillslope gradient; such failures are sensitive to changes in the climate and tectonic stress conditions (Agliardi et al, 2009;Huggel et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Chronology and Geomorphological Activity of the Akdag Rock Avalanche (SW Turkey)

et al. 2020

Self Cite

View full text Add to dashboard Cite

Large rock-slope failures are among the primary geohazards in high mountain areas. These rock avalanches and rockslides constitute most of the world's largest landslide deposits. This study focuses on the formation and geomorphological activity of the Akdag landslide complex located on the southern slope of Mount Akdag, SW Turkey. We employed detailed mapping in the field, spatial and morphometric analysis using GIS and remote sensing technologies, and surface exposure dating with cosmogenic 36 Cl to reconstruct the chronology of the landslide complex. For the analysis of cosmogenic 36 Cl, we collected 18 surface samples from calcareous boulders within the landslide deposit. Our field mapping shows that the Akdag rock avalanche is a large and active slope failure developed between carbonates and flysch. The rock-avalanche deposits cover an area of 9.8 km 2 and together with the primary and secondary slope failures which form the landslide complex, cover an area of 15 km 2. The Akdag rock avalanche is one of the largest (3 × 10 8 m 3) known bedrock landslides in Turkey. Cosmogenic 36 Cl exposure ages indicate that the main collapse occurred at 8.3 ± 1.4 ka (2σ), followed by secondary failures. We dated one of the latter to 1.1 ± 0.2 ka (2σ). Based on field evidence, we surmise that increased water discharge in the springs along the carbonate-flysch contact zone played a key role in the Early Holocene failure.

show abstract

The Kandersteg rock avalanche (Switzerland): integrated analysis of a late Holocene catastrophic event

Cited by 20 publications

References 82 publications

Deciphering the evolution of the Bleis Marscha rock glacier (Val d'Err, eastern Switzerland) with cosmogenic nuclide exposure dating, aerial image correlation, and finite element modeling

Deciphering the evolution of the Bleis Marscha rock glacier (Val d'Err, eastern Switzerland) with cosmogenic nuclide exposure dating, aerial image correlation, and finite element modeling

Deciphering the evolution of the Bleis Marscha rock glacier (Val d'Err, eastern Switzerland) with cosmogenic nuclide exposure dating, aerial image correlation, and finite-element modelling

Chronology and Geomorphological Activity of the Akdag Rock Avalanche (SW Turkey)

Contact Info

Product

Resources

About