Brief communication: Collapse of 4 Mm<sup>3</sup> of ice from a cirque glacier in the Central Andes of Argentina

Falaschi, Daniel; Kääb, Andreas; Paul, Frank; Tadono, Takeo; Rivera, Juan Antonio; Lenzano, Luis

doi:10.5194/tc-13-997-2019

Cited by 29 publications

(29 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Aru twin glacier detachments -which released 68 and 83 10 6 m 3 of glacier ice -have recently raised the questions of whether and where such events may have happened before or need to be expected in the future, which factors (including climate change) ultimately allow low-angle glaciers to detach from their bed in such a catastrophic manner, and what this means for mountain hazard management. Indeed, several detachments similar to the Aru events, though smaller in magnitude, have been detected since (Falaschi et. al., 2019;Paul 2019;Jacquemart et al, 2020).…”

Section: Introductionmentioning

confidence: 83%

“…The 4 10 6 m 3 detachment of Leñas Glacier between 5 and 14 March 2007 was discovered only recently, since it happened in 600 a very remote region and had no down-stream impacts. Meanwhile, the case is described in detail by Falaschi et al (2019). (Fig.…”

Section: Leñas 2007 Argentinean Andesmentioning

confidence: 99%

“…The bed characteristics of the glacier are not known, but large amounts of fine sediments were found over the run-out area of the event. A number of glacier surges are documented in the 604 wider region but not for Leñas Glacier itself(Falaschi et al, 2018a(Falaschi et al, , 2019. At the location of the later head scarp of the detachment, pronounced transverse crevasses are visible in airphotos from 1970 and in a satellite image from a few weeks 606 before the event (SPOT5).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Sudden large-volume detachments of low-angle mountain glaciers – more frequent than thought

Kaeaeb¹,

Jacquemart²,

Gilbert³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract. The detachment of large parts of low-angle mountain glaciers, resulting in massive ice-rock avalanches, have so far been believed to be a unique type of event, made known to the global scientific community first for the 2002 Kolka Glacier detachment, Caucasus Mountains, and then for the 2016 collapses of two glaciers in the Aru range, Tibet. Since 2016, several so-far unknown glacier detachments have been discovered and described, and new ones occurred. In the current contribution, we compile, compare and discuss 19 actual or possible large-volume detachments of low-angle mountain glaciers at nine different sites in the Caucasus, the Pamirs, Tibet, Alaska’s St. Elias mountains, and the Southern Andes. Many of the detachments reached volumes in the order of 10–100 million m3. Commonalities and differences between the cases investigated suggest that a set of different conditions drives a transient combination of factors related to low basal friction, high driving stress, concentration of shear stress, and low resistance to exceed stability thresholds. Particularly, soft bedrocks below the detached glaciers seem to be a common condition among the observed events, as they offer smooth contact areas between the glacier and its substratum while being prone to till-strength weakening and eventually basal failure under high pore-water pressure. Surface slopes of the detached glaciers range between around 10° and 20°, possibly on the one hand low enough to enable development of thick and thus large-volume glaciers, and on the other hand steep enough to allow critical basal stresses to build up. Most of the ice-rock avalanches resulting from the detachments in this study have a particularly low angle of reach, down to around 0.1 (apparent friction angle), likely due to their high ice content and connected liquefaction potential, the ready availability of soft basal slurries and large amounts of basal water, and the smooth topographic setting typical for glacial valleys. Low-angle glacier detachments combine elements, and likely also physical processes of glacier surges and ice break-offs from steep glaciers. The surge-like temporal evolution ahead of several detachments or their geographic proximity to other surge-type glaciers suggests the glacier detachments investigated can be interpreted as end-members of the continuum of surge-like glacier instabilities. Though rare, glacier detachments appear more frequent than previously thought and disclose, despite local differences in conditions and precursory evolutions, the fundamental and critical potential of low-angle soft glacier beds to fail catastrophically.

show abstract

Section: Introductionmentioning

confidence: 83%

Section: Leñas 2007 Argentinean Andesmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Sudden large-volume detachments of low-angle mountain glaciers – more frequent than thought

Kaeaeb¹,

Jacquemart²,

Gilbert³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…The numerous recent discoveries of glacier detachments around the world (Kääb et al, 2018;Gilbert et al, 2018;Falaschi https://doi.org/10.5194/nhess-2020-285 Preprint. Discussion started: 8 October 2020 c Author(s) 2020.…”

Section: Discussionmentioning

confidence: 99%

Glacier detachments and rock-ice avalanches in the Petra Pervogo range, Tajikistan (1973–2019)

Leinß¹,

Bernardini²,

Jacquemart³

et al. 2020

Preprint

View full text Add to dashboard Cite

Abstract. Glacier detachments are a rare phenomenon of glacier instability, whereof only a handful have been documented to date. Common to all known cases are the large detached volumes of many million cubic meters of ice and long runout distances. Recently, two detachments of smaller size were observed in the Petra Pervogo range, north west of the Pamir mountains, Tajikistan. Using a variety of satellite images, we identified in total 9 detachments and several ice and rock avalanches which occurred in four different catchments between 1973 and 2019. The avalanche run out distances vary between 2 and 19 km and detached volumes range between 2 and [8.8 × 106] m3. Seven out of nine detachments occurred between July and September in years with temperature above the past 46-years trend. No active glacier surge was observed immediately before detachment, but elevation model (DEM) differences indicate a surge-like behavior about 10 years before the two largest detachments. Instead, one glacier retreated before detachment while the other remained stagnant before increased sliding pronounced the impending detachment. To put results into a regional context, we analyzed DEM differences over the entire Pamir range and found 237 surging glaciers, predominantly in the north-western part where soft and fine-grained rock-types are common. We are confident that no major events were missed due to lack of satellite data, because destroyed vegetation remains visible in the normalized difference vegetation index (NDVI), several years after large mass flows, e.g. about 10 years for the Kolka–Karmadon rock-ice avalanche. From the large number of detachments which occurred under very similar conditions we conclude that rising temperatures combined with soft, fine-grained sediments are very critical components favouring the detachment of entire valley glaciers.

show abstract

“…Moreover, CHIRPS achieved better results in the region with summer precipitation maximum, given that precipitation was largely overestimated during the cold semester maximum. In view of this performance, the CHIRPS database was used for the assessment of a glacier collapse over the Central Andes of Argentina in a region with scarce meteorological information [25]. e CHIRPS estimations also gained attention as input for climate monitoring tools.…”

Section: Introductionmentioning

confidence: 99%

Using CHIRPS Dataset to Assess Wet and Dry Conditions along the Semiarid Central-Western Argentina

Rivera

Hinrichs

Marianetti

2019

Advances in Meteorology

View full text Add to dashboard Cite

e Climate Hazards group Infrared Precipitation with Stations (CHIRPS) dataset was conceived as a tool for monitoring drought and environmental change over land. Recent validation efforts along South America have assessed its suitability for reproducing the main spatial and temporal features of precipitation. Nevertheless, little has been done regarding the ability of CHIRPS for the assessment of wet and dry conditions, particularly in areas where in situ precipitation records are scarce. In this paper, we investigated the performance of CHIRPS for monitoring wet and dry events along the semiarid Central-Western Argentina. Using the Standardized Precipitation Index (SPI), we compared the CHIRPS database with records from 49 meteorological stations along the study area for the period 1987-2016. Results indicate that the CHIRPS dataset adequately reproduced the temporal variability of SPI on multiple timescales (1 month, 3 months, and 6 months), particularly in the region dominated by warm season precipitation. e large overestimation of the seasonal precipitation in the region dominated by cold season precipitation can introduce errors that are reflected in the performance of CHIRPS over the western portion of the domain. e frequency of wet and dry classes was accurately reproduced by CHIRPS on timescales larger than 1 month (SPI1), given the existence of a wet bias that produces an underestimation of the frequency of zero values. is bias is further translated to the evaluation of the SPI1 during the spatial and temporal assessment of historical dry (1998) and wet (2016) events, especially for the classification of extreme dry/wet months. e results from the evaluation indicate that CHIRPS is a suitable tool for assessing dry and wet conditions for timescales longer than 1 month and can support decision-making process within the hydrometeorological agencies over the region.

show abstract

Brief communication: Collapse of 4 Mm³ of ice from a cirque glacier in the Central Andes of Argentina

Cited by 29 publications

References 22 publications

Sudden large-volume detachments of low-angle mountain glaciers – more frequent than thought

Sudden large-volume detachments of low-angle mountain glaciers – more frequent than thought

Glacier detachments and rock-ice avalanches in the Petra Pervogo range, Tajikistan (1973–2019)

Using CHIRPS Dataset to Assess Wet and Dry Conditions along the Semiarid Central-Western Argentina

Contact Info

Product

Resources

About

Brief communication: Collapse of 4 Mm3 of ice from a cirque glacier in the Central Andes of Argentina

Cited by 29 publications

References 22 publications

Sudden large-volume detachments of low-angle mountain glaciers – more frequent than thought

Sudden large-volume detachments of low-angle mountain glaciers – more frequent than thought

Glacier detachments and rock-ice avalanches in the Petra Pervogo range, Tajikistan (1973–2019)

Using CHIRPS Dataset to Assess Wet and Dry Conditions along the Semiarid Central-Western Argentina

Contact Info

Product

Resources

About

Brief communication: Collapse of 4 Mm³ of ice from a cirque glacier in the Central Andes of Argentina