In the shadow of mountain glaciers
Understanding the climate-threats to water, nutrients and sediments supplied by glacier-fed rivers in Earth’s high mountains
Nearly 10% of the world’s population live in the high mountains and in the shadow of glaciers. They rely on the meltwater from these glaciers for domestic use, croplands and for industry. In the upper parts of some major rivers, such as the Indus, more than 80% of river flows are glacial meltwater. Yet as glaciers recede in a warming climate, changes to river flows are likely (i.e. water quantity), threatening supply. What is less well studied is the impact of glacier retreat on the quality of this water - for example, how good it is to drink. Rivers draining glaciers often has a unique quality in terms of its chemical and sediment loads, which shape critical services provided to ecosystems and people. Changes in freshwater flows, routing and chemical weathering of rocks minerals will shift as glaciers recede - all altering the quantity and quality of water available for people and biota.
Research Projects
Funded by the following grants/funders:
NERC/CONICYT PISCES: Patagonian Ice field SHrinkage impaCts on downstream EcosystemA
NERC/CONCYTEC (Newton Fund) CASCADA - CAscading impacts of peruvian glacier Shrinkage on biogeochemical Cycling and Acid Drainage in Aquatic ecosystems
GCRF Investment Grant “Glacial Flour Power“
UKIERI “Biogeochemical impacts of Himalayan Glacier melting”
Impact of melting Patagonian glaciers on downstream fjord ecosystems
The Northern and Southern Patagonian Ice Fields are the largest masses of glacial ice in the Southern Hemisphere outside of Antarctica and are melting at world record rates. Their accelerating melt is driving increased discharge of glacial meltwater (and sediment) to fjords, causing freshening. The impacts on fjord and marine life are poorly unknown, but will likely impact productivity and biodiversity of these fragile ecosystems. The NERC/CONICYT-funded PISCES project is showing that the retreat of Patagonia’s glaciers will have large impacts on freshwater, sediment and nutrient input to fjords and their valuable food-webs. Image credit: J. Hawkings.
Retreating glaciers and toxic rivers in the Peruvian high Andes
The Peruvian Andes hosts the largest concentration of tropical glaciers in the world, a quarter of which lie in the Cordillera Blanca. Here, almost a third of glacier area has been lost in the last two decades due to climate warming, but it is thought to be having an unusual impact on water quality. As glacially-ground up sulphide-rich rocks are exposed in front of the retreating ice, oxidation of these sulphides is causing acidification and metal toxicity in lakes and rivers - a kind of glacier “acid-mine-drainage” effect. What will happen in the future and what is the solution? The Newton-Funded CASCADA project seeks to work this out.
Himalayan glaciers and glacial flour power
The Hindu-Kush-Himalaya hosts more than 50,000 glaciers which traverse astonishingly diverse climates, geologies and nations. It is becoming well-established that glacier retreat here has been widespread here over the past century, and that this will cause a reduction in river flows in the coming decades. Pressures on land and water resources are high across this mountain range which hosts a quarter of a billion people. Here, our interdisciplinary GCRF/UKIERI-funded Glacial Flour Power project is investigating novel methods of soil care. Glaciers that flow by sliding over water-lubricated rock, grind this rock into very fine flour - “glacial flour”. This compresses the normal cycle of rock breakdown in a soil from hundreds to thousands of years to < 1 year. The foundation of nutrients in most soils is rock - can glacial flour provide a novel natural soil fertility treatment for crops? Image credit: P. Nienow.
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Patagonia
Marshall, M.G., A.M. Kellerman, J.L. Wadham, J.R. Hawkings, G. Daneri, R. Torres, H.V. Pryer, A. Beaton, H.C. Ng, A. Urra, L.F. Robinson, R.G. M. Spencer. 2021. Seasonal changes in dissolved organic matter composition in a Patagonian fjord affected by glacier melt inputs, Frontiers in Marine Science, doi: 10.3389/fmars.2021.612386.
Pryer, H.V., J.R. Hawkings, J.L. Wadham, L.F. Robinson, K.H. Hendry, J.E. Hatton, A.M. Kellerman, S. Bertrand, B. Gill-Olivas, R.A. Brooker, G. Daneri, V. Häussermann. 2020. The Influence of Glacial Cover on Riverine Silicon and iron exports in Patagonia, Global Biogeochemical Cycles. 34, Doi:10.1029/2020GB006611.
Pryer, H., J.E. Hatton, J.L. Wadham, J. Hawkings, L. F. Robinson, A.M. Kellerman, A. Covey, M. Marshall, A. Urra, G. Daneri, V. Häussermann, K.R. Hendry. 2020. The effects of glacier cover on riverine silicon isotope compositions and trace metal size partitioning in Patagonia, Frontiers in Geochemistry, 8(368), Doi:0.3389/feart.2020.00368.
Piret, L., S. Bertrand, J.R. Hawkings, M.E. Kylander, F. Torrejón, J.L. Wadham. 2020. High‐resolution fjord sediment record of a receding glacier with growing intermediate proglacial lake (Steffen Fjord, Chilean Patagonia), Earth Surface Processes and Landforms, Doi:10.1002/esp.5015.
