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Climate change and glacial disasters directly affect the Andean periglacial populations in the environmental, social, economic and cultural spheres. Regional atmospheric warming is causing an increasing retreat of glaciers in the Cordillera Blanca, Peru. The melting of these glaciers causes, among other consequences, the formation of new glacial lagoons and an increase in volume of the pre-existing lagoons; both phenomena increase the possibility of glacial disasters. Thus, this paper reports an investigation of perceptions and adaptations to climatic change and glacial disasters in the Cordillera Blanca, Department of Ancash, Peru, through the ethnographic method with the campesino communities of Vicos and Humacchuco; this method included observations and semi-structured interviews with managers and campesinos. The measures adopted by the managers are, predominantly, engineering to reduce disasters, such as increasing of dike sizes and lagoon drainages. The retreat of the glaciers, as noted by the campesino communities themselves, is the main perception of the impacts of climate change. We suggest that the choice of safe places to live in campesino communities is the main strategy of adaptation and is related to an ancestral ethnoknowledge. The reterritorialization of sites susceptible to glacial disasters is not only due to the need to have a place (to plant, to live), but is also due to the topophilic feelings formed by the affective link between a person and a place. There is a central and structural issue that adds to these problems: the development model prevailing in Peruvian postcolonial society tends to complicate possible strategies for adapting to climate change in the Andes. Resumo As mudanças climáticas e os desastres glaciais afetam diretamente as populações periglaciais andinas nas esferas ambientais, sociais, econômicas e culturais. O aquecimento atmosférico regional está provocando a crescente retração das geleiras na Cordilheira Branca (Peru) ao longo das últimas décadas. O derretimento dessas geleiras implica, entre outras consequências, na formação de lagoas glaciais e o acréscimo do volume daquelas pré-existentes, o que aumenta a possibilidade de desastres glaciais. Assim, este trabalho relata investigações sobre percepções e adaptações às mudanças climáticas e aos desastres glaciais na Cordilheira Branca, Departamento de Ancash, Peru, por meio do método etnográfico junto às comunidades campesinas de Vicos e Humacchuco, incluindo a observação direta e entrevistas semiestruturadas com gestores e campesinos. As medidas adotadas pelos gestores são, predominantemente, obras de engenharia para reduzir os desastres, como o aumento dos diques e do desague das lagoas. A retração das geleiras, como apontada pelas próprias comunidades campesinas, é a principal percepção dos impactos das mudanças climáticas. Sugerimos que a escolha de locais seguros para habitar pelas comunidades campesinas é a principal estratégia de adaptação e é relacionada à um etnoconhecimento ancestral. A reterritorialização dos locais suscetíveis aos desastres glaciais se dá pela necessidade de se ter um lugar (para plantar, para viver), mas também devido aos sentimentos topofílicos pelo elo afetivo entre a pessoa e o lugar. Há uma questão central, estrutural e estruturante, que se soma a esses problemas: o modelo de desenvolvimento vigente na sociedade pós-colonial peruana tende a complexificar possíveis estratégias de adaptação às mudanças climáticas nos Andes.

Development of vegetation communities in areas of Antarctica without permanent ice cover emphasizes the need for effective remote sensing techniques for proper monitoring of local environmental changes. Detection and mapping of vegetation by image classification remains limited in the Antarctic environment due to the complexity of its surface cover, and the spatial heterogeneity and spectral homogeneity of cryptogamic vegetation. As ultra-high resolution aerial images allow a comprehensive analysis of vegetation, this study aims to identify different types of vegetation cover (i.e., algae, mosses, and lichens) in an ice-free area of Hope Bay, on the northern tip of the Antarctic Peninsula. Using the geographic object-based image analysis (GEOBIA) approach, remote sensing data sets are tested in the random forest classifier in order to distinguish vegetation classes within vegetated areas. Because species of algae, mosses, and lichens may have similar spectral characteristics, subclasses are established. The results show that when only the mean values of green, red, and NIR bands are considered, the subclasses have low separability. Variations in accuracy and visual changes are identified according to the set of features used in the classification. Accuracy improves when multilayer information is used. A combination of spectral and morphometric products and by-products provides the best result for the detection and delineation of different types of vegetation, with an overall accuracy of 0.966 and a Kappa coefficient of 0.946. The method allowed for the identification of units primarily composed of algae, mosses, and lichens as well as differences in communities. This study demonstrates that ultra-high spatial resolution data can provide the necessary properties for the classification of vegetation in Maritime Antarctica, even in images obtained by sensors with low spectral resolution

The remote sensing techniques must be used to obtain long-term information in remote areas, like the Antarctic continent, to monitor the environmental productivity and its changes. The aim of this work was to analyze the surface reflectance profile patterns for the Antarctic biological soil crusts (algae, lichens, and mosses) in an area of Nelson Island (South Shetland Islands, maritime Antarctic), calculated from Landsat and Sentinel-2 images to identify its similarities and differences due to targets, sensors and acquired date. The surface reflectance values for Antarctic biological soil crusts are similar for those observed for biological soil crusts in other Earth extreme environments, like deserts. In Landsat images, the differences among biological soil crusts surface reflectance were identified at visible and near-infrared wavelengths and for Sentinel-2 images, the differences occur at visible, red-edge and shortwave infrared wavelengths, showing the feasibility of using surface reflectance products to identify these different crusts, despite its inherent pixel spectral mixture. Long-term biophysical parameters from such crusts as retrieved from orbital data is not possible due to very low cloud-free images over the Antarctic, which prevents building a consistent surface reflectance time-series which covers all biological soil crusts growth season.

This work deals with two distinct datasets, a well preserved H2O2 concentration data from firn cores at a high deposition location and a temperature time series, estimated from the daily records from four Antarctic stations around the Antarctic Peninsula. With them we have produced a time scale, an ice–core chronology, for the 133  deep borehole DP-07-1 from Plateau Detroit, Antarctic Peninsula. We constructed the chronology through a non-linear pairing transformation of the two series, based entirely on mathematical optimization, compensating the peroxide frequency scaling, reflecting the gradual thinning of the annual firn layers with depth. We resorted to a dynamic time warping algorithm to find an optimal alignment between the two data series, allowing for the thinning of the annual firn layers with depth and the estimation of their original thicknesses at time of deposition. The core chronology spanning from Jan-1980 to Dec-2010 for the borehole reach, a time frame of a mere 30 years period, revealing a fairly stable 11 year average for the accumulation rate of 2.5 m w.e./y.

In order to interpret the ionic variability in snow and firn from Patriot Hills (80º18’S, 81º21’W) to the South Pole, we determined the major ions concentrations and isotopic ratios of five snow and firn cores (less than 46 m deep) for the 200 first fractions, collected during the 2004–2005 Chilean-Brazilian traverse. After cleaning the samples (in a cold room) and melting it (in a class 100 clean room), we determined the Na+ , K+ , Mg2+, Ca2+, MS- (CH3 SO3 - ), Cl- , NO3 - and SO4 2- concentrations by ion chromatography, with detection limits from 0.3 to 1.8 µg L-1 depending on the ion. For deuterium/hydrogen isotopic ratio (δD) the precision is 0.5‰. We dated the samples with annual precision and ±2 years accuracy, by counting the Na+ , nssSO4 2- (non-sea-salt sulfate) and δD annual layers. Then we obtained, for the five snow and firn cores sites, the mean net snow accumulation rates. They show a negative correlation (r >0.4, module) with increasing elevation and sea distance, yet responding to local superficial features and katabatic winds occurrence. The snow and firn cores reveal alterations in the sea salt aerosols Na+ /Cl- ratios, but the aerosols produced during sea ice formation appear only on the nearest sites of the coast. The NO3 - , as the MS- record, indicates the occurrence of post-depositional processes connected to volcanic events and photochemical reactions, which intensity increases on glaze surfaces., Com o objetivo de interpretar a variabilidade no conteúdo iônico da neve e do firn entre Patriot Hills (80º18’S, 81º21’W) e o Polo Sul Geográfico, foram determinadas as concentrações dos íons majoritários e as razões isotópicas das 200 primeiras frações de cinco testemunhos de neve e firn (com profundidades de até 46 m), durante a travessia chileno-brasileira ocorrida no verão de 2004–2005. Após as amostras serem limpas (em câmara fria) e derretidas (em sala limpa classe 100), os íons Na+ , K+ , Mg2+, Ca2+, MS- (CH3 SO3 - ), Cl- , NO3 - e SO4 2- foram analisados por cromatografia iônica, com limites de detecção entre 0,3 e 1,8 µg L-1, dependendo do íon. A razão isotópica deutério/hidrogênio (δD) foi determinada com precisão de 0,5‰. Dataram-se as amostras, com precisão anual e exatidão de ±2 anos, a partir da contagem anual de camadas de neve e de firn dos perfis de Na+ , nssSO4 2- (sulfato não proveniente do sal marinho, do inglês non-sea-salt sulfate) e δD. A partir da datação obteve-se as taxas médias de acumulação líquida de neve para os sítios de cada testemunho de neve e firn, as quais apresentaram uma correlação negativa (r > 0,4, em módulo) à medida que se aumentavam a elevação e a distância da costa, respondendo, ainda, às feições superficiais locais e à ocorrência de ventos catabáticos. Constataram-se aerossóis do sal marinho com alteração na razão Na+ /Cl- no registro dos cinco testemunhos de neve e firn, mas a presença de aerossóis produzidos na formação do gelo marinho só foi identificada nos sítios mais próximos à costa. Os registros de NO3 - , assim como os de MS- , indicam a provável ocorrência de processos pós- -deposicionais, ligados tanto a eventos vulcânicos, como a reações fotoquímicas acentuadas por superfícies com formação de esmalte de gelo.

This article examines the temporal relations between the oxygen stable isotopes ratio (δ18O) in an ice core from the Nevado Illimani, Bolivia (16°37’S, 67°46’W), with precipitation series from South America. We used δ18O data from the upper 50 m of this core and precipitation monthly totals collected at 890 weather stations in South America in the period 1979–2008. Precipitation data were arranged in a grid with ~2° latitude and longitude resolution, for zoning the spatial temporal variability, using the Principal Components Analysis Mode–S. The relation between the δ18O record with drought and rain events above the South America mean values changes seasonally due to spatial migration of transport mechanisms and moisture convergence. The precipitation interannual temporal variability in the equatorial and subtropical regions is the one with the greatest similarity to δ18O variations in the Nevado Illimani. This relationship results from the control of precipitation anomalies in the two regions by the surface temperature of the equatorial Pacific and North Atlantic oceans, at temporal frequencies from 24 to 60 months. The δ18O and precipitation series have temporal cycles of high spectral frequency that vary independently, as those cycles are controlled by local factors., Este artigo examina as relações temporais entre a série de razão de isótopos estáveis de oxigênio (δ18O), obtida de um testemunho de gelo do Nevado Illimani, Bolívia (16°37’S, 67°46’W), com séries da precipitação sobre a América do Sul. Utilizou-se dados de δ18O dos primeiros 50 m desse testemunho e os totais mensais de precipitação coletados em 890 estações meteorológicas sul-americanas no período entre 1979–2008. As amostras da precipitação foram dispostas em uma grade com resolução de ~ 2° de latitude e longitude, para o zoneamento espacial da variabilidade temporal, utilizando-se da Análise das Componentes Principais (ACP) no Modo-S. As relações entre o registro do δ18O com a ocorrência de secas e chuvas acima da média na América do Sul alteram-se sazonalmente em função da migração espacial dos mecanismos de transporte e convergência da umidade. A variabilidade temporal interanual da precipitação nas regiões equatorial e subtropical é a que possui maior semelhança com a variação do δ18O no Nevado Illimani. Essa relação é explicada pelo controle da temperatura superficial dos oceanos Pacífico Equatorial e Atlântico Norte sobre as anomalias de precipitação nas duas regiões e que ocorrem com frequências temporais entre 24 e 60 meses. As séries do δ18O e da precipitação possuem ciclos temporais de alta frequência espectral que variam independentemente, porque esses ciclos são controlados por fatores locais.

This paper aims to investigate environmental changes in Vieville Glacier, located in Admiralty Bay, King George Island, Antarctica, with the use of the Geography Information System (GIS) and meteorological data. Aerial photographs (1956 and 1979), SPOT (1988, 1995 e 2000) and COSMO-SkyMed (2011) images were used to mapping and generate data of the glacial areas to provide the glacial pattern of retreat reconstruction. The retreat data demonstrated that the Viéville Glacier had 23.49 km² in area in 1956 and changed for 19.01 km² in 2011 without glacial front advance in the studied period. The Digital Terrain Model (DTM) was used for generated hypsometric, slope, aspect and hillshade maps. Image digital processing results demonstrated the spatial dispersion pattern of the water plume zones in glaciomarine environment (in front section of the glacier). These results indicated that the sediment delivery and meltwater flow are related with glacial retreat process through of the subglacial melt with wet-based subglacial conditions., Este artigo objetiva analisar as mudanças ambientais na Geleira Viéville, localizada na Baía do Almirantado, Ilha Rei George, Antártica, com a utilização de um Sistema de Informações Geográficas (SIG) e dados meteorológicos. Por meio de fotografias aéreas (1956 e 1979), imagens SPOT (1988, 1995 e 2000) e COSMO-SkyMed (2011) foram mapeadas as áreas em diferentes anos da geleira para auxiliar na reconstrução do padrão de retração. Os dados de retração demonstram que a área da geleira passou de 23,49 km² de área em 1956 para 19,01 km² em 2011, sem avanço frontal neste período. Com base no Modelo Digital de Terreno (MDT) foram derivados mapas de hipsometria, declividade, aspecto e sombreamento. Técnicas de processamento digital de imagens demonstraram o padrão de dispersão espacial da turbidez na água no ambiente glaciomarinho (na parte frontal da geleira). Estes resultados indicam que o aporte de sedimentos e fluxo da água de degelo está relacionado com o processo de retração da geleira por fusão subglacial em condições de regime termo-basal úmido.