Supraglacial debris is known to strongly influence the distribution of glacier surface melt. Since melt inputs drive the formation and evolution of glacial drainage systems, it should follow that the drainage systems of debris-covered glaciers will differ from those of debris-free glaciers. This would have implications for the proglacial runoff regime, subglacial erosion and glacier dynamics. This paper presents analysis of return curves from 33 successful dye injections into the extensively debris-covered Miage Glacier, Italian Alps. It demonstrates that the spatial distribution of supraglacial debris influences the structure and seasonal evolution of the glacial drainage system. Where the debris cover is continuous, melt is lower and the surface topography is chaotic, with many small supraglacial catchments. These factors result in an inefficient englacial/subglacial drainage network beneath continuous debris, which drains to the conduit system emanating from the upper ablation zone. Melt rates are high in areas of clean and dirty ice above the continuous debris. Runoff from these areas is concentrated by inter-moraine troughs into large supraglacial streams, which encourages the early-season development of an efficient englacial/subglacial conduit system downstream of this area. Drainage efficiency from the debris-covered area increases over the melt season but dye-trace transit velocity remains lower than from moulins on the upper glacier. Future runoff models should account for the influence of supraglacial debris on the hydrological system.

Do debris-covered glaciers demonstrate distinctive hydrological behaviour compared to clean glaciers? / C.L. Fyffe, B.W. Brock, M.P. Kirkbride, D.W.F. Mair, N.S. Arnold, C. Smiraglia, G. Diolaiuti, F. Diotri. - In: JOURNAL OF HYDROLOGY. - ISSN 0022-1694. - 570(2019 Mar), pp. 584-597. [10.1016/j.jhydrol.2018.12.069]

Do debris-covered glaciers demonstrate distinctive hydrological behaviour compared to clean glaciers?

C. Smiraglia;G. Diolaiuti
Penultimo
;
2019-03

Abstract

Supraglacial debris is known to strongly influence the distribution of glacier surface melt. Since melt inputs drive the formation and evolution of glacial drainage systems, it should follow that the drainage systems of debris-covered glaciers will differ from those of debris-free glaciers. This would have implications for the proglacial runoff regime, subglacial erosion and glacier dynamics. This paper presents analysis of return curves from 33 successful dye injections into the extensively debris-covered Miage Glacier, Italian Alps. It demonstrates that the spatial distribution of supraglacial debris influences the structure and seasonal evolution of the glacial drainage system. Where the debris cover is continuous, melt is lower and the surface topography is chaotic, with many small supraglacial catchments. These factors result in an inefficient englacial/subglacial drainage network beneath continuous debris, which drains to the conduit system emanating from the upper ablation zone. Melt rates are high in areas of clean and dirty ice above the continuous debris. Runoff from these areas is concentrated by inter-moraine troughs into large supraglacial streams, which encourages the early-season development of an efficient englacial/subglacial conduit system downstream of this area. Drainage efficiency from the debris-covered area increases over the melt season but dye-trace transit velocity remains lower than from moulins on the upper glacier. Future runoff models should account for the influence of supraglacial debris on the hydrological system.
debris-covered glaciers; dye tracing; glacier-hydrology
Settore GEO/04 - Geografia Fisica e Geomorfologia
Settore ICAR/02 - Costruzioni Idrauliche e Marittime e Idrologia
gen-2019
Article (author)
File in questo prodotto:
File Dimensione Formato  
Fyffe et al. Do debris-covered glaciers demonstrate distinctive hydrological behaviour compared to clean glaciers.pdf

accesso aperto

Tipologia: Pre-print (manoscritto inviato all'editore)
Dimensione 2.18 MB
Formato Adobe PDF
2.18 MB Adobe PDF Visualizza/Apri
1-s2.0-S0022169419300472-main.pdf

accesso aperto

Tipologia: Publisher's version/PDF
Dimensione 5.03 MB
Formato Adobe PDF
5.03 MB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/636022
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 18
  • ???jsp.display-item.citation.isi??? 18
social impact