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This paper presents a glacial geomorphological map relating to two rapidly receding glaciers in the Cordillera Darwin Icefield. The Marinelli marine-terminating glacier and Pigafetta freshwater-terminating glacier are selected to represent different glacial regimes producing different geomorphological records under similar climatic conditions. We combine mapping from satellite and aerial imagery with fieldwork, updating limited previous mapping. The map reveals two principal glacial landform assemblages: (1) a marine-terminating system, dominated by the formation of a large arcuate terminal morainic complex, glaciolacustrine landforms (shorelines) and extended ice-contact topography in the Fiordo Marinelli area; and (2) an assemblage of sequential frontal moraine ridges and outwash plains that formed when the former land-terminating Pigafetta glacier retreated from the Bahía Ainsworth area. Finally, the map is designed as a basis for future chronological campaigns and to enable a refined reconstruction of the glacial history of these two glaciers in a climatologically significant part of the world. [ABSTRACT FROM AUTHOR]

This paper presents evidence for a neotectonic influence on Late Pleistocene/Holocene records of environmental change in the southern Strait of Magellan. We concentrate on one site, Puerto del Hambre, a key location for reconstructing palaeoenvironmental change in southernmost South America. We report geomorphological, structural geological, seismic and topographic data that all show the site has been affected by postglacial faulting. There is also indirect evidence from the site stratigraphy that the site has been displaced. Also, recent faulting explains some of the puzzles associated with interpretation of the palaeoenvironmental record at Puerto del Hambre. The implication of this work is that neotectonic faulting had a pervasive influence in the southern part of the Strait of Magellan and southernmost Tierra del Fuego, and thus affects glacial or sea level reconstructions in the area. [ABSTRACT FROM AUTHOR]

Agriculture in the Aconcagua Basin is both vital to Chile's economy and critically dependent on water resources from snow and glaciers. Expanding croplands, a growing population, and a changing climate are all expected to exacerbate water scarcity in this arid region where agriculture requires 7.1 × 108 m3 of water for irrigation annually. We investigate agricultural water resources in the Aconcagua Basin by examining the drivers of and trends in river discharge, calculating approximate crop water demand, and assessing the potential for future water scarcity given discharge rates and agricultural demand. We find that growing-season (October to March) discharge is significantly correlated with austral winter precipitation and the El Niño-Southern Oscillation. Austral winter precipitation provides snow that melts during the growing season, supplying water for agricultural irrigation. Time series analysis shows that temperature increased by 0.23°C per decade between 1965 and 2017, and snow cover frequency decreased 2.7% per decade over the relatively short time period of 2000 to 2017. Based on historical discharge data and our assessment of current agricultural water demand, we show that the Aconcagua Basin is already water-scarce, experiencing demand exceeding supply approximately three out of every 10 years. [ABSTRACT FROM AUTHOR]

This work analyzed the application of Sentinel-2 multispectral imagery and GLIMS data for mapping glacier retreat and to estimate glacier area changes of Mount Melimoyu, located in northern Patagonia, Chile for the period between 1970 and 2017. The results showed a decrease of about 35.61% in the area for the period analyzed and there is a continuing retreating trend in the region. The decreasing trend in mean annual precipitation may explain the recent glacier changes, which indicates a large sensibility for meteorological variability of glaciers, which is influenced by geomorphometry and glacier area, in the region. Using Sentinel 2 imagery, we provided inventory of rock glaciers in the study area. Glacier outlines obtained through manual delineation showed comparable results with the glacier outlines using Sentinel-2 MSI data in the study area, which shows greater accuracy in glacier mapping using Sentinel-2 data. [ABSTRACT FROM AUTHOR]

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ABSTRACT. Glacially derived sediments and structures vary systematically with topographic position along ice-contact slopes near the margin of former temperate piedmont glaciers in the southern Lake District, Chile. Features along lower positions of the slopes include glaciolacustrine sediments and large-scale thrusting. Middle slope features include low-angle subglacial thrusting of thin slices of lacustrine sediment. Upper slope features include high-angle thrusting, and lodgement and flow till. Locally, the same ordering of these features occurs in vertical sequence. A common theme that unifies the processes represented by these features is the distribution of hydrostatic pressure. Thicker ice (producing higher glacier overburden pressures) and aquicludes of fine-grained sediments toward the center of the basin result in high hydrostatic pressures, whereas thin ice and porous out-wash reduce these pressures at the top of the ice-contact slopes. However, such a distribution cannot completely explain the observed vertical sequences; hence, local variations in hydrostatic pressure because of lithologic contrasts probably play a role. Nowhere along the ice-contact slope are pervasively deformed glacial sediments observed; therefore they cannot be invoked to explain the low glacier profiles of these piedmont glacier lobes. Study area [ABSTRACT FROM AUTHOR]