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Tropical glaciers are important indicators of climate change, provide freshwater resources for downstream communities, and form an important component of the hydrological cycle. Understanding the dynamics and patterns of behaviour of tropical palaeoglaciers is important for interpreting their sensitivities and vulnerabilities. Glacier advances in the high tropical Peruvian Andes occurred multiple times during the last glacial cycle and Holocene, leaving complex geomorphological evidence on the landscape. The substantial topographic, geological and climatic variability in this region leads to high geomorphic diversity. However, few detailed geomorphological studies have been conducted to date, leading to considerable uncertainty in the behaviours and drivers of tropical palaeoglaciers. Here, we provide a detailed geomorphological analysis of the Cordillera Vilcanota, Cusco region, southern Peru (71°W, 13.7°S), and use morphostratigraphic principles to reconstruct the former maximum icefield extent and palaeoglacier advances. Across this domain, we mapped ~23,000 features encompassing five key environments: glacier, subglacial, ice‐marginal, fluvial and lacustrine. The mapped features show evidence of both modern‐day polythermal and temperate ice margins, with low meltwater volumes leading to small‐scale glaciofluvial landform formation. However, larger moraines, beyond those well‐dated to the Younger Dryas and Antarctic Cold Reversal, assumed to represent Last Glacial Maximum and earlier advances, suggest that conditions were temperate and drained by more substantial rivers, with coupled flow of ice and till, and evidence of subglacial scouring, drumlin formation and the deposition of substantial moraines and large palaeosandar. Our reconstructed maximum icefield covers 2,660 km 2 and was drained by multiple topographically constrained ice lobes across the region. In the north, these ice lobes reached an elevation of 3,500 m asl, but were limited to above 4,500 m asl in the south, likely reflecting the dominant moisture sources. Our geomorphological mapping reveals seven clear ice margins, morphostratigraphically correlated across the study region, reflecting at least seven palaeoglacier advances during the last glacial cycle, including the Late Glacial period and the Holocene.

The water, food and energy security of millions of people is at risk in several regions of the tropical Andes because climate change is altering water storage in high Andean wetlands ( bofedales ), lakes and glacier ice. These features play a crucial role in delaying water release, particularly in many semiarid regions with pronounced seasonal precipitation, sustaining baseflows and water quality. Changing water availability impacts both high Andean pastoralist systems and other productive systems downstream, including bigger cities in the inter‐Andean valleys. Here we outline the hydrological and geomorphological relationships between glaciers, lakes and bofedal wetlands, and the way in which catchment features such as moraines, talus slopes and sandar interact with catchment hydrology in the tropical Andes of Peru. We present a geomorphological map of catchment features in the Cordillera Vilcanota, Southern Peru, and explore how these features can impact hydrogeological processes. We suggest the ways in which well mapped and dated catchment features can provide a damming or groundwater/surface water exchange mechanism for bofedal development and sustenance. We find that glacial lakes will grow modestly as glaciers retreat, but will not provide an equivalent water storage to compensate for the loss of glacier ice. We find that bofedales are well developed within glacial limits, with glacial processes such as erosion and formation of moraines providing the poorly drained conditions suitable for their development. However, we find that the majority of the bofedales are largely hydrologically independent of contemporary glaciers, and could perhaps buffer water supply as glaciers dwindle and disappear. Such analysis enables an improved understanding of the timeframe for the formation of bofedal wetlands and for them to provide their key ecosystem services of water retention and remediation capacity, buffering drought, providing forage for high‐Andean livestock herding, carbon storing and sequestration.

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