Analysis of the Temporal Evolution of Ice Aprons in the Mont-Blanc Massif Using X and C-Band SAR Images

Kaushik, Suvrat; Cerino, Bastien; Trouvé, E.; Karbou, Fatima; Yan, Yajing; Ravanel, Ludovic; Magnin, Florence

doi:10.3389/frsen.2022.930021

Cited by 4 publications

(3 citation statements)

References 89 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This monitoring and previous observations (Guillet and Ravanel, 2020) suggest that summer melting combined with the absence of accumulation has probably been a fairly general trend since the early 2000s. The efficiency of the summer melting is corroborated by Kaushik and others (2022 c ) who investigated the evolution of the physical backscatter properties and surface changes of IAs by exploiting time series of X- and C-band synthetic aperture radar (SAR) images from PAZ and Sentinel-1 satellites. SAR data indeed provide information about the seasonal behaviour of IAs since physical changes of IA surfaces modify the backscattering of radar waves.…”

Section: Evolution Of Ice Aprons At Different Timescales and Related ...mentioning

confidence: 78%

Ice aprons on steep high-alpine slopes: insights from the Mont-Blanc massif, Western Alps

et al. 2023

Self Cite

View full text Add to dashboard Cite

Ice aprons are defined as very small ice bodies covering steep rock slopes. They have only been the subject of increased scientific interest for a few years, despite the fact that they are a condition for mountaineering and obvious elements in the high-alpine landscapes. However, very little is known about their distribution, evolution and physical characteristics. In this paper, we review the existing knowledge on ice aprons, which have almost exclusively been investigated in the Mont-Blanc massif, Western Alps. We supplement this review with novel results from recent surveys of ice aprons. We used a wide array of methodologies, from remote sensing (multi-source imagery) to in situ (stakes and thermal monitoring) and laboratory (radiocarbon dating and texture analysis) glaciological investigations. In the Mont-Blanc massif, ice aprons occupy 4.2 km2 within the alpine permafrost zone. Temperature measured at the ice–rock interface is indeed largely negative. Thinness of ice aprons coupled with the cold context implies a quasi-stationary shear regime without basal Sliding. Only ice at the surface can possibly melt in warm periods. After a shrinking period from the end of the Little Ice Age to the mid-to-late-1960s, ice aprons experienced a short period of expansion, followed by an accelerated shrinkage since the beginning of the 21st century. This shrinkage now favours rockfall triggering and poses a serious threat to a glaciological heritage since ice aprons host several-thousand-year-old ice. Finally, we synthesize this information to assess the existing definition of ice aprons, and propose some future research directions.

show abstract

Section: Evolution Of Ice Aprons At Different Timescales and Related ...mentioning

confidence: 78%

Ice aprons on steep high-alpine slopes: insights from the Mont-Blanc massif, Western Alps

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

“…Winsvold et al [28] used SAR data to map the glacier facies like superimposed ice area, firn, ice and wet snow zones. In contrast, Kaushik et al [30] computed the coefficient of variations of the backscattering signal to analyze ice aprons. Heilig et al [31] also used the coefficient of variations over glacierized areas to select summer reference images for mapping wet snow.…”

Section: Introductionmentioning

confidence: 99%

Snowmelt Dynamics in a Temperate Glacier Using Sentinel-1 SAR Images: A Case Study on Saint-Sorlin Glacier, French Alps

Turbé,

Karbou,

Rabatel

et al. 2024

IEEE J. Sel. Top. Appl. Earth Observations Remote Sensing

Self Cite

View full text Add to dashboard Cite

Snow and glaciers play a crucial role in various applications such as hydrology, climate and avalanche risk assessment. Remote sensing is a powerful tool for monitoring the snowpack and melt in glacier catchments. SAR imagery, which measures the backscattering signal in the microwave spectrum, is particularly useful for studying snow and glacier-related issues: while it is almost insensitive to cloud cover, it is sensitive to some snow/glacier properties such as liquid water content. In this study, we analyze the snowmelt dynamics in the Saint-Sorlin Glacier catchment in the French Alps using SAR images in Cband from Sentinel-1. Our primary objective is to understand the spatial and temporal variabilities of the SAR signal in a glacierized area by monitoring the SAR signal in regions of snow/ice ablation, accumulation, and outside the glacier. We also rely on complementary meteorological, model and optical data. A second objective is to compare and assess several approaches from the literature to characterize the snowmelt dynamics on a variety of surfaces.Our study confirms and extends the capability of previous methodologies to identify crucial melting phases, such as moistening of the snowpack, saturation, and run-off phases, using SAR backscatter time series. These melting phases were compared with the ones estimated from liquid water content and snow water equivalent simulations simulated with the Crocus state-ofthe-art snowpack model. The transition from snow-covered to an icy surface on ablation areas was detected using VH-polarized images, as SAR imagery is sensitive to surface roughness.

show abstract

“…Further, the development of satellite remote sensing over the last decades has revolutionized our ability to map and monitor glaciers, as shown by the studies of [28][29][30]. [31,32] have also shown the potential to map and monitor small hanging glaciers and IAs from a time series of RaDAR images.…”

Section: Introductionmentioning

confidence: 99%

Ice Aprons in the Mont Blanc Massif (Western European Alps): Topographic Characteristics and Relations with Glaciers and Other Types of Perennial Surface Ice Features

et al. 2022

Self Cite

View full text Add to dashboard Cite

Ice aprons are poorly studied and not well-defined thin ice bodies adhering to high altitude steep rock faces, but are present in most Alpine-type high mountain environments worldwide. This study aims to precisely define ice aprons based on a detailed analysis of their topographical characteristics in the Mont Blanc massif (western European Alps). For this, we accurately identified and precisely mapped 423 ice aprons using a combination of high-resolution optical satellite images from 2019. To better understand their relationship with other types of glaciers, especially the steep slope glaciers and other surface ice bodies, we built a detailed inventory at the scale of the massif that incorporates nine different types of perennial surface ice bodies. In addition, an analysis using different topographic factors helped us to better understand the preferred locations of the ice aprons. We show that they predominantly occur on west-oriented steep and topographically rugged rock slopes above the local Equilibrium Line Altitude (~3200 m a.s.l.), with concave profile curvatures around them that facilitate snow accumulation. They are also found in areas underlain by permafrost. The extensive inventory also helped us to identify different types of ice aprons based on their relationships with glaciers/ice bodies. The analysis shows that ice aprons existing at the headwall of large glaciers above a bergschrund are the most dominant ice apron type in the study area, with ~82% of the total.

show abstract

Analysis of the Temporal Evolution of Ice Aprons in the Mont-Blanc Massif Using X and C-Band SAR Images

Cited by 4 publications

References 89 publications

Ice aprons on steep high-alpine slopes: insights from the Mont-Blanc massif, Western Alps

Ice aprons on steep high-alpine slopes: insights from the Mont-Blanc massif, Western Alps

Snowmelt Dynamics in a Temperate Glacier Using Sentinel-1 SAR Images: A Case Study on Saint-Sorlin Glacier, French Alps

Ice Aprons in the Mont Blanc Massif (Western European Alps): Topographic Characteristics and Relations with Glaciers and Other Types of Perennial Surface Ice Features

Contact Info

Product

Resources

About