Dry calving processes at the ice cliff of Strandline Glacier northern Victoria Land, Antarctica

Diolaiuti, Guglielmina; Smiraglia, Claudio; Vassena, G.; Motta, Michele

doi:10.3189/172756404781813880

Cited by 6 publications

(5 citation statements)

References 6 publications

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“…In the Planpincieux Glacier, we identified three main instability processes: disaggregation , slab fracture and water tunnelling . The former two are related to the glacier geometry; disaggregation is typical of ice cliffs (Diolaiuti and others, 2004; Pralong and Funk, 2006; Deline and others, 2012). In the Mont Blanc massif, disaggregation is frequent in warm glaciers and it involves small volumes (usually <1000 m 3 ) (Alean, 1985b; Deline and others, 2012).…”

Section: Discussionmentioning

confidence: 99%

Classification and kinematics of the Planpincieux Glacier break-offs using photographic time-lapse analysis

2020

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Herein, we present results obtained from time-lapse imagery acquired by a digital single-lens reflex camera during 2014–18 used to monitor the Planpincieux Glacier on the Italian side of the Grandes Jorasses (Mont Blanc massif). We processed the images using image cross-correlation to measure the surface kinematics of the most active lobe of the glacier that presents a high velocity and frequent ice detachments. During the monitoring, we observed two or three periods of sharp acceleration per year that culminated with large break-offs followed by analogous decelerations. Overall, we registered more than 350 failures with a volume >100 m3, of which, 14 events had volumes larger than 10 000 m3. The study identified a monotonic positive relationship between the velocity and failure volume that may be used to estimate the volume of the collapses before an event. We identified the thresholds of velocity and acceleration that characterise the activation of the speed-up periods. The study allowed the characterisation of three different instability processes that lead to the break-off of ice chunks from the glacier terminus: (i) disaggregation, (ii) slab fracture and (iii) water tunnelling failure which can be differentiated based on the rheology, the volume involved and the trigger process.

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Section: Discussionmentioning

confidence: 99%

Classification and kinematics of the Planpincieux Glacier break-offs using photographic time-lapse analysis

2020

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“…In addition, several nodes with known coordinates were positioned near the glaciers to improve the accuracy of the measurements taken by differential GPS with short bases according to Diolaiuti et al (2004). To obtain DEMs of the glacier surface and bedrock morphology (from GPR data), the field surveys were carried out using high density global positioning system (GPS) point data (i.e., 8000 points/km 2 ) and interpolating the data with the kriging algorithm.…”

Section: Glacier Monitoringmentioning

confidence: 99%

“…To obtain DEMs of the glacier surface and bedrock morphology (from GPR data), the field surveys were carried out using high density global positioning system (GPS) point data (i.e., 8000 points/km 2 ) and interpolating the data with the kriging algorithm. In addition, several nodes with known coordinates were positioned near the glaciers to improve the accuracy of the measurements taken by differential GPS with short bases according to Diolaiuti et al (2004).…”

Section: Glacier Monitoringmentioning

confidence: 99%

Accelerating Climate Change Impacts on Alpine Glacier Forefield Ecosystems in the European Alps

Cannone

Diolaiuti

Guglielmin

et al. 2008

Ecological Applications

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156

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In the European Alps the increase in air temperature was more than twice the increase in global mean temperature over the last 50 years. The abiotic (glacial) and the biotic components (plants and vegetation) of the mountain environment are showing ample evidence of climate change impacts. In the Alps most small glaciers (80% of total glacial coverage and an important contribution to water resources) could disappear in the next decades. Recently climate change was demonstrated to affect higher levels of ecological systems, with vegetation exhibiting surface area changes, indicating that alpine and nival vegetation may be able to respond in a fast and flexible way in response to 1-2 degrees C warming. We analyzed the glacier evolution (terminus fluctuations, mass balances, surface area variations), local climate, and vegetation succession on the forefield of Sforzellina Glacier (Upper Valtellina, central Italian Alps) over the past three decades. We aimed to quantify the impacts of climate change on coupled biotic and abiotic components of high alpine ecosystems, to verify if an acceleration was occurring on them during the last decade (i.e., 1996-2006) and to assess whether new specific strategies were adopted for plant colonization and development. All the glaciological data indicate that a glacial retreat and shrinkage occurred and was much stronger after 2002 than during the last 35 years. Vegetation started to colonize surfaces deglaciated for only one year, with a rate at least four times greater than that reported in the literature for the establishment of scattered individuals and about two times greater for the well-established discontinuous early-successional community. The colonization strategy changed: the first colonizers are early-successional, scree slopes, and perennial clonal species with high phenotypic plasticity rather than pioneer and snowbed species. This impressive acceleration coincided with only slight local summer warming (approximately -0.5 degree C) and a poorly documented local decrease in the snow cover depth and duration. Are we facing accelerated ecological responses to climatic changes and/or did we go beyond a threshold over which major ecosystem changes may occur in response to even minor climatic variations?

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“…Using the orthophotos as a base layer in a GIS environment we delimited the glacier boundaries as polylines; in several case we referred also to glacier boundaries marked on the field by DGPS campaigns (in the manner explained by Diolaiuti et al (2004) and Diolaiuti et al (2005)). The planimetric accuracy of the glacier limits evaluated through DGPS measurements was found equal to ±1 m.…”

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confidence: 99%

The fluctuations of italian glaciers during the last century: a contribution to knowledge about alpine glacier changes

Citterio

Diolaiuti

Smiraglia

et al. 2007

Geografiska Annaler: Series A, Physical Geography

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. This paper describes the recent evolution of Italian glaciers through an analysis of all available terminus fluctuation data that the authors have entered in a glaciers database (named GLAD) containing 883 records collected on glaciers from 1908 to 2002. Furthermore, a representative subset of data (249 glaciers located in Lombardy) was analysed regarding surface area changes. For the analysis of terminus fluctuations, the glaciers were sorted by size classes according to length. The data showed that during the 20th century Italian Alpine glaciers underwent a generalized retreat, with one distinct and well documented readvance episode that occurred between the 1970s and mid‐1980s, and a poorly documented one around the early 1920s. The rates of terminus advance and retreat have changed without significant delays for the larger glaciers with respect to the smaller ones. However, the smaller the glacier, the more limited the advance (if any) during the 1970s and early 1980s. The behaviour of glaciers shorter than 1 km appears to have changed in the last decade, and between 1993 and 2002 they retreated at a very high rate. The analysis of the subset of data led to a quanti‐fication of surface reduction of c. 10% from 1992 to 1999 for glaciers in Lombardy. Small glaciers proved to contribute strongly to total area loss: in 1999, 232 glaciers (c. 90% of the total) were smaller than 1 km2, covering 27.2 km2 (less than 30% of the total area), but accounted for 58% of the total loss in area (they had lost 7.4 km2).

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Dry calving processes at the ice cliff of Strandline Glacier northern Victoria Land, Antarctica

Cited by 6 publications

References 6 publications

Classification and kinematics of the Planpincieux Glacier break-offs using photographic time-lapse analysis

Classification and kinematics of the Planpincieux Glacier break-offs using photographic time-lapse analysis

Accelerating Climate Change Impacts on Alpine Glacier Forefield Ecosystems in the European Alps

The fluctuations of italian glaciers during the last century: a contribution to knowledge about alpine glacier changes

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