TY - JOUR
T1 - Hydrology of debris-covered glaciers in High Mountain Asia
AU - Miles, Katie E.
AU - Hubbard, Bryn
AU - Irvine-fynn, Tristram D.l.
AU - Miles, Evan S.
AU - Quincey, Duncan J.
AU - Rowan, Ann V.
N1 - Funding Information:
This research was supported by the ‘EverDrill’ Natural Environment Research Council Grant awarded to Aberystwyth University ( NE/P002021 ) and the Universities of Leeds and Sheffield ( NE/P00265X ). KM is funded by an AberDoc PhD Studentship, with fieldwork costs supported by the Mount Everest Foundation and Postgraduate Research Awards from the British Society for Geomorphology , the Royal Geographical Society (with IBG), and Aberystwyth University Department of Geography and Earth Sciences. TIF acknowledges the Leverhulme Trust ( RF-2018-584/4 ). The authors would like to thank Antony Smith (Aberystwyth University) for the initial illustration of Figure 2 and redrawing Figure 10. Figure 4 is reproduced from the Journal of Glaciology with permission of the International Glaciological Society. Figure 8 is reproduced according to a Creative Commons Attribution 4.0 License. Figure 10 is reproduced with permission of the publisher. The authors are also grateful to Himalayan Research Expeditions for organising the logistics that supported fieldwork in Nepal, and in particular Mahesh Magar for guiding and navigation. The authors thank two anonymous reviewers, and two previous reviewers in The Cryosphere Discussions, all the comments of which led to a much-improved manuscript.
Funding Information:
This research was supported by the ‘EverDrill’ Natural Environment Research Council Grant awarded to Aberystwyth University (NE/P002021) and the Universities of Leeds and Sheffield (NE/P00265X). KM is funded by an AberDoc PhD Studentship, with fieldwork costs supported by the Mount Everest Foundation and Postgraduate Research Awards from the British Society for Geomorphology, the Royal Geographical Society (with IBG), and Aberystwyth University Department of Geography and Earth Sciences. TIF acknowledges the Leverhulme Trust (RF-2018-584/4). The authors would like to thank Antony Smith (Aberystwyth University) for the initial illustration of Figure 2 and redrawing Figure 10. Figure 4 is reproduced from the Journal of Glaciology with permission of the International Glaciological Society. Figure 8 is reproduced according to a Creative Commons Attribution 4.0 License. Figure 10 is reproduced with permission of the publisher. The authors are also grateful to Himalayan Research Expeditions for organising the logistics that supported fieldwork in Nepal, and in particular Mahesh Magar for guiding and navigation. The authors thank two anonymous reviewers, and two previous reviewers in The Cryosphere Discussions, all the comments of which led to a much-improved manuscript.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/8/1
Y1 - 2020/8/1
N2 - The hydrological characteristics of debris-covered glaciers are known to be fundamentally different from those of clean-ice glaciers, even within the same climatological, geological, and geomorphological setting. Understanding how these characteristics influence the timing and magnitude of meltwater discharge is particularly important for regions where downstream communities rely on this resource for sanitation, irrigation, and hydropower, such as High Mountain Asia. The hydrology of debris-covered glaciers is complex: rugged surface topographies typically route meltwater through compound supraglacial-englacial systems involving both channels and ponds, as well as pathways that remain unknown. Low-gradient tongues that extend several kilometres retard water conveyance and promote englacial storage. Englacial conduits are frequently abandoned and reactivated as water supply changes, new lines of permeability are exploited, and drainage is captured due to high rates of surface and subsurface change. Seasonal influences, such as the monsoon, are superimposed on these distinctive characteristics, reorganising surface and subsurface drainage rapidly from one season to the next. Recent advances in understanding have mostly come from studies aimed at quantifying and describing supraglacial processes; little is known about the subsurface hydrology, particularly the nature (or even existence) of subglacial drainage. In this review, we consider in turn the supraglacial, englacial, subglacial, and proglacial hydrological domains of debris-covered glaciers in High Mountain Asia. We summarise different lines of evidence to establish the current state of knowledge and, in doing so, identify major knowledge gaps. Finally, we use this information to suggest six themes for future hydrological research at High Mountain Asian debris-covered glaciers in order to make timely long-term predictions of changes in the water they supply.
AB - The hydrological characteristics of debris-covered glaciers are known to be fundamentally different from those of clean-ice glaciers, even within the same climatological, geological, and geomorphological setting. Understanding how these characteristics influence the timing and magnitude of meltwater discharge is particularly important for regions where downstream communities rely on this resource for sanitation, irrigation, and hydropower, such as High Mountain Asia. The hydrology of debris-covered glaciers is complex: rugged surface topographies typically route meltwater through compound supraglacial-englacial systems involving both channels and ponds, as well as pathways that remain unknown. Low-gradient tongues that extend several kilometres retard water conveyance and promote englacial storage. Englacial conduits are frequently abandoned and reactivated as water supply changes, new lines of permeability are exploited, and drainage is captured due to high rates of surface and subsurface change. Seasonal influences, such as the monsoon, are superimposed on these distinctive characteristics, reorganising surface and subsurface drainage rapidly from one season to the next. Recent advances in understanding have mostly come from studies aimed at quantifying and describing supraglacial processes; little is known about the subsurface hydrology, particularly the nature (or even existence) of subglacial drainage. In this review, we consider in turn the supraglacial, englacial, subglacial, and proglacial hydrological domains of debris-covered glaciers in High Mountain Asia. We summarise different lines of evidence to establish the current state of knowledge and, in doing so, identify major knowledge gaps. Finally, we use this information to suggest six themes for future hydrological research at High Mountain Asian debris-covered glaciers in order to make timely long-term predictions of changes in the water they supply.
KW - Debris-covered glaciers
KW - Glacier hydrology
KW - Glaciers
KW - High Mountain Asia
UR - http://www.scopus.com/inward/record.url?scp=85086086728&partnerID=8YFLogxK
U2 - 10.1016/j.earscirev.2020.103212
DO - 10.1016/j.earscirev.2020.103212
M3 - Review Article
SN - 0012-8252
VL - 207
JO - Earth-Science Reviews
JF - Earth-Science Reviews
M1 - 103212
ER -