Assessing ice-cliff backwasting and its contribution to total ablation of debris-covered Miage glacier, Mont Blanc massif, Italy

Reid, Tim; Brock, Benjamin

doi:10.3189/2014jog13j045

Cited by 125 publications

(223 citation statements)

References 16 publications

(20 reference statements)

Supporting

Mentioning

208

Contrasting

Order By: Relevance

“…These methods are therefore best suited for debriscovered glaciers for which the necessary measurements to compute the relationships or factors are available, and their applicability for regional-scale studies such as this one is uncertain. Thus, important future steps for glacier CMB studies in the Karakoram include increasing the accuracy and spatial detail of the debris thickness field and its physical properties; improving our understanding of moisture fluxes between the debris and the atmosphere and accounting for subgrid-scale surface heterogeneity (e.g., by introducing a treatment of ice cliffs; Reid and Brock, 2014). Nonetheless, by providing an estimate of the controlling influence of debris, these simulations contribute to a greater understanding of glacier behavior in the Karakoram.…”

Section: Discussionmentioning

confidence: 99%

Impact of debris cover on glacier ablation and atmosphere–glacier feedbacks in the Karakoram

et al. 2015

View full text Add to dashboard Cite

Abstract. The Karakoram range of the Hindu-Kush Himalaya is characterized by both extensive glaciation and a widespread prevalence of surficial debris cover on the glaciers. Surface debris exerts a strong control on glacier surface-energy and mass fluxes and, by modifying surface boundary conditions, has the potential to alter atmosphereglacier feedbacks. To date, the influence of debris on Karakoram glaciers has only been directly assessed by a small number of glaciological measurements over short periods. Here, we include supraglacial debris in a high-resolution, interactively coupled atmosphere-glacier modeling system. To investigate glaciological and meteorological changes that arise due to the presence of debris, we perform two simulations using the coupled model from 1 May to 1 October 2004: one that treats all glacier surfaces as debris-free and one that introduces a simplified specification for the debris thickness. The basin-averaged impact of debris is a reduction in ablation of ∼ 14 %, although the difference exceeds 5 m w.e. on the lowest-altitude glacier tongues. The relatively modest reduction in basin-mean mass loss results in part from non-negligible sub-debris melt rates under thicker covers and from compensating increases in melt under thinner debris, and may help to explain the lack of distinct differences in recent elevation changes between clean and debriscovered ice. The presence of debris also strongly alters the surface boundary condition and thus heat exchanges with the atmosphere; near-surface meteorological fields at lower elevations and their vertical gradients; and the atmospheric boundary layer development. These findings are relevant for glacio-hydrological studies on debris-covered glaciers and contribute towards an improved understanding of glacier behavior in the Karakoram.

show abstract

Section: Discussionmentioning

confidence: 99%

Impact of debris cover on glacier ablation and atmosphere–glacier feedbacks in the Karakoram

et al. 2015

View full text Add to dashboard Cite

show abstract

“…5a). 16 Spillway and Rongbuk lakes migrated up-glacier over the observation period and their overall 17 size diminished (Fig. 5a, Table 3).…”

Section: Glacier-scale Pond Dynamicsmentioning

confidence: 99%

“…Nie et al, 2013;Liu et al, 2015) and glacier 15 extent mapping (Nie et al, 2010). We applied it to the panchromatic band of each 16 WorldView, GeoEye, and QuickBird image using ENVI 5.2, to effectively delineate the 1 edges of supraglacial ponds (Fig. 3).…”

Section: Object Based Image Analysis (Obia)mentioning

confidence: 99%

“…We analyse Google Earth, Quickbird, GeoEye 13 and WorldView imagery (0.7 -2 m) covering nine glaciers in the Everest region of the 14 central Himalaya. Our objectives are to: (1) characterise the spatial evolution of supraglacial 15 ponds on an individual glacier scale; (2) quantify short-term seasonal and inter-annual change 16 in supraglacial pond area in the region; (3) evaluate the implications of using medium-17 resolution satellite imagery (e.g. 15 -30 m) to delineate the full spectrum of pond sizes that 18 exist on Himalayan debris-covered glaciers.…”

mentioning

confidence: 99%

See 1 more Smart Citation

The dynamics of supraglacial ponds in the Everest region, central Himalaya

Watson

Quincey

Carrivick

et al. 2016

Global and Planetary Change

109

174

View full text Add to dashboard Cite

6The dynamics of supraglacial pond development in the Everest region are not well 7 constrained at a glacier scale, despite their known importance for meltwater storage, 8 promoting ablation, and transmitting thermal energy englacially during drainage events. 9Here, we use fine-resolution (~ 0.5 -2 m) satellite imagery to reveal the spatiotemporal 10 dynamics of 9,340 supraglacial ponds across nine glaciers in the Everest region, ~2000 -11 2015. Six of our nine study glaciers displayed a net increase in ponded area over their 12 observation periods. However, large inter-and intra-annual changes in ponded area were 13 observed of up to 17 % (Khumbu Glacier), and 52 % (Ama Dablam) respectively. 14 Additionally, two of the fastest expanding lakes (Spillway and Rongbuk) partially drained 15 over our study period. The Khumbu Glacier is developing a chain of connected ponds in the 16 lower ablation area, which is indicative of a trajectory towards large lake development. We 17show that use of medium-resolution imagery (e.g. 30 m Landsat) is likely to lead to large 18 classification omissions of supraglacial ponds, on the order of 15 -88 % of ponded area, and 19 77 -99 % of the total number of ponds. Fine-resolution imagery is therefore required if the 20 full spectrum of ponds that exist on the surface of debris-covered glaciers are to be analysed. 21

show abstract

“…The presence of ice cliffs and supraglacial lakes are another unique characteristic of glaciers ( Figures 5 and 6) as both of these features are associated with high-magnitude ablation, and ice cliffs contribute considerably to the overall ablation of a glacier even though they often cover only a small percentage of the glacier surface [120,[134][135][136][137]. Theoretically, these features and glacier ablation form a positive feedback loop-an ice cliff exposes clean ice while supraglacial lakes exhibit low albedo both of which increase ablation.…”

Section: Ice Cliffs and Supraglacial Lakesmentioning

confidence: 99%

Climate–Glacier Dynamics and Topographic Forcing in the Karakoram Himalaya: Concepts, Issues and Research Directions

Dobreva

Bishop

Bush

2017

Water

View full text Add to dashboard Cite

Abstract:Understanding climate-glacier dynamics in High Mountain Asia is of critical importance to address issues including water resources, sea-level rise, mountain geodynamics, natural hazards and ecosystem sustainability. The Karakoram Himalaya is arguably the least understood region, given its extreme topography, climate-system coupling, and advancing and surge-type glaciers that exhibit complex flow patterns. Glacier fluctuations in the Karakoram Himalaya are highly variable in space and time because of numerous controlling factors, including the westerlies, the Indian summer monsoon, various teleconnections, topographic effects, glacier debris-cover characteristics, glacier dynamics, and geological conditions. The influence of the integrative coupling of forcing factors, however, has not been adequately assessed for characterizing the glaciers in the Karakoram Himalaya. Given the scarcity of in-situ data and the difficulty of conducting fieldwork on these glaciers, recent research has focused on utilizing remote sensing, geospatial technologies, and scientific modeling to obtain baseline information about the state of glaciers in the region. This review summarizes our current knowledge of glaciers, climate-glacier interaction, and topographic forcing in the Karakoram Himalaya, and demonstrates the complexities in mountain geodynamics that influence climate-glacier dynamics. Innovative analysis is also presented in support of our review and discussion.

show abstract

Assessing ice-cliff backwasting and its contribution to total ablation of debris-covered Miage glacier, Mont Blanc massif, Italy

Cited by 125 publications

References 16 publications

Impact of debris cover on glacier ablation and atmosphere–glacier feedbacks in the Karakoram

Impact of debris cover on glacier ablation and atmosphere–glacier feedbacks in the Karakoram

The dynamics of supraglacial ponds in the Everest region, central Himalaya

Climate–Glacier Dynamics and Topographic Forcing in the Karakoram Himalaya: Concepts, Issues and Research Directions

Contact Info

Product

Resources

About