Kátia Kellem da Rosa

Sobre el calentamiento global en la isla Rey Jorge: procesos y evidencias en el Glaciar Wanda y su entorno

Geologic, geomorphologic and volcanic aspects, meteorological data and vegetation, both fossil and current, are considered in order to find answers to the dynamics of King George Island glaciers, into theSouth Shetlands Islands, with special emphasis on aspects of the glaciological dynamics submitted by Wanda glacier located in Martel inlet, Almirantazgo Sound, as well as by relevant aspects shown by theEcology glacier, located at the neighborhood. Glaciological and geomorphologic field analysis carried out, the morphological results of glacial sediments samples at laboratory, plant fossils kds, as well asthe interpretation of volcanic history of the Peninsula Antartica, joint with volcanic residual forms and piroclastic materials, also the direct experience of rain over ice, the hydrological responses generated, and the development of not pioneer plants, among other elements, reveal a complex island glaciological evolution. So, temperature rate increasing and the occurrence of rain in a significant number of days per year, scenery that seems not new in the past of the island, and the possible influence of latent heat derived fiom the volcanic context means in the case of Wanda glacier clear negative effects on his mass balance, registering from clear evidence of Cont retreat to moments of accelerated melting and generation of small torrents and lagoons, some of them with persistent character discontinuously damrned by Cont moraines at the coast, as weii as other of seasondy formed into the glacial environment.

Collins Glacier Retreat Process and Regional Climatic Variations, King George Island, Antarctica

Abstract This paper investigates the recent climatic variability and changes in snow line and ice front position in Collins Glacier, King George Island, South Shetland Islands, Antarctic Peninsula. This region has recorded one of the largest temperature increases in the past fifty years and has been demonstrated to be highly sensitive to climate changes. To monitor recent changes (1983–2006), we determined the fluctuations of the terminus and snow line of the glacier via remote sensing data and field observation in the summer of 2013. We conclude that the Collins Glacier has responded slowly to regional climate changes (decades or even centuries), as glacial responses to climatic events do not depend solely on one environmental variable. The glacier presented more retreat and elevation of the snow line in the north sector. The retreat data are correlated with the mean monthly temperature and annual number of days of melting‐degree variations.

Formas glaciales y procesos glaciológicos del glaciar templado Wanda, Shetland del Sur

This paper presents the geomorphic mapping of the Wanda Glacier proglacial environment, King George Island, South Shetlands. All together investigates the glaciological dynamics related to the glacial landforms in the study area. The mapping was based on field analysis and image interpretation. The interpretation was also made by mean of identification and interpretation of the samples in laboratoty. Glaciofluvial, glaciomarine and subglacial processes predominate in the study area. As a result from the recent glacial retreat, several landforms and proglacial deposits, such as flutes, morainic ridges, striated rocks, have been exposed. Abraded and subglacially transported sediments predominate in the deglaciation environments, with meltwater flow in the bed. The generated map contributes in improving the knowledge about the processes that influence the glacial geomorphology and geodynamics. Furthermore this study serves as support to monitoring environmental change facing the glacier retreat processes as effect of climate variability verified in the study area.

Análise das mudanças ambientais da Geleira Viéville, Baía do Almirantado, Ilha Rei George, Antártica

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 Vieville 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.

Recent changes in the Wanda Glacier, King George Island, Antarctica

Recent glaciological changes in Wanda Glacier, King George Island (KGI), South Shetland Islands (61°54’ S and 62°16’S, 57°35’W and 59°02’W) off the Antarctic Peninsula, were quantified by ice flow velocity, direction and fluctuation of glacier termini measurements. Topographic changes and DGPS surveys as well as transverse and longitudinal profiles were carried out to generate a Digital Surface Model. Results show that Wanda Glacier has a small drainage basin, a high retreat rate through fusion processes and reduced ice thickness if compared to other glaciers in KGI. Surface-area changes are assessed using historical satellite imagery from 1979 to 2011. Wanda glacier lost about 31 % of its original (1.5 km2 of area in 1979). The current continuous and fast retreat phase is attributed to the recent regional warming. Maximum ice surface velocity, measured using a stake network, reached 2.2 cm d-1 during the period of 2007–2011. Transverse profiles show the influence of the topography on the ice flow. Due to its small size and thermal conditions, Wanda Glacier responds rapidly to climatic variations, revealing its relevance for environmental studies.Recent glaciological changes in Wanda Glacier, King George Island (KGI), South Shetland Islands (61°54’ S and 62°16’S, 57°35’W and 59°02’W) off the Antarctic Peninsula, were quantified by ice flow velocity, direction and fluctuation of glacier termini measurements. Topographic changes and DGPS surveys as well as transverse and longitudinal profiles were carried out to generate a Digital Surface Model. Results show that Wanda Glacier has a small drainage basin, a high retreat rate through fusion processes and reduced ice thickness if compared to other glaciers in KGI. Surface-area changes are assessed using historical satellite imagery from 1979 to 2011. Wanda glacier lost about 31 % of its original (1.5 km² of area in 1979). The current continuous and fast retreat phase is attributed to the recent regional warming. Maximum ice surface velocity, measured using a stake network, reached 2.2 cm d -1 during the period of 2007–2011. Transverse profiles show the influence of the topography on the ice flow. Due to its small size and thermal conditions, Wanda Glacier responds rapidly to climatic variations, revealing its relevance for environmental studies.

Consequences of rapid environmental changes in the Arctic

This article analyses the environmental changes that have occurred in the Arctic over the past five decades. The study was conducted by collecting data in scientific papers, books and also NGOs reports associate with the Arctic issue. During the past 50 years, the Arctic showed the fastest warming on the planet, more than twice the world average, it caused rapid environmental changes, such as reducing the volume of glaciers, which contributed to the increase in the mean sea level; the melting of permafrost, which releases large amounts of carbon dioxide (CO2) and methane (CH4) into the atmosphere, enhancing the greenhouse effect; migration of vegetation towards the north, changing the availability of food and animal migration patterns; increasing sea surface temperature, which can cause migration of fish shoals in areas further north. The fastest change, the one that draws the most attention, is the drastic reduction in the area covered by sea ice in the summer. The Arctic is a climate change beacon because of anthropogenic and walks quickly to become a different environment from the time known from of the great discoveries. In a few decades there will be no sea ice in the summer, causing clear changes in the physical environment and with serious consequences for the biota.

Using cosmo-skymed images to detect wet snow cover on the Kraków Ice Field, King George Island, Antarctica

Abstract This work analysed the spatio-temporal variation of snow cover on the Kraków Ice Field, located in the King George Island, Antarctica. High spatial resolution images of COSMO-SkyMed were used in this study. These X-band images are vertically and horizontally co-polarized and their intensity data were converted to amplitude (dB). The COSMO-SkyMed images were classified by a minimum distance algorithm and post-classified based on knowledge of adjacency relationships of snow zones. Hypsometric, slope, aspect and solar radiation maps to support the interpretation of backscatter patterns in the COSMO-SkyMed images. Three radar zones were classified in these images: percolation, slush and wet snow radar zone. Positive surface air temperatures and rainfall events, registered from a meteorological station, lead to increase in wet snow and slush zones. The COSMO-SkyMed images and minimum distance algorithm were adequate to discriminate the snow cover and to assess the supraglacial melting pattern during the ablation season in the study area.

Análisis Sedimentológico y geomorfológico de áreas lacustres en la Península Fildes, Isla Rey Jorge, Antártica Marítima

Geomorphological features and sedimentary characteristics are analized from five sets of shallow sediment cores collected in lakes in the Fildes Peninsula, King George Island. The geomorphology of the area was observed and sediments samples were obtained at field activities during the XXXI Brazilian Antarctic Operation (March-April/2013). Biogeochemical characteristics, physical parameters, mineralogical composition, particle size distribution, macroscopic characteristics of the sediments and satellite images were analized. Preliminary results indicate climatic and environmental changes in north-south transect of the peninsula. The mineralogical composition is associated with geological structure of the area, where basaltic rocks predominate. The particle size variation reflects different sediment source environments. Macroscopic analysis and mineralogical composition variation reflect the action of weathering along the peninsula. The sediments also have potential mineralization and subsequent release of greenhouse gases. A preliminary map of the classification of the lakes is presented. In addition, it was identified that wetland sediment presents methane production rates (CH4) about 40 times larger and more sensitive to the effect of global warming compared to lake sediment. Subpolar aquatic ecosystems sediments from Maritime Antarctica can be a preferential site for the effects of climate variability.

Identification of Environmental Change Through Sedimentary Characterization and Research of Glaciogenic and Paraglaciais Processes on Glacial Environment of Wanda Glacier, King George Island, Antarctica

This study arms identify sediment characteristics related to glaciogenics deposits and modification with paraglacial processes in Wanda Glacier proglacial area, King George Island, Antarctica. The methodology was developed through field activities performed during summers in 2007, 2010 and 2011. The sediments were analyzed to determine the particle size distribution and morphoscopical characteristics. This study presents results of the samples sediment interpretation in Wanda Glacier proglacial area. The sediment analyses provided the discrimination of the glaciogenics sediments and paraglacial modified sediments, and was evidence for environment changes in the study area due to the increase surface atmospheric temperature and liquid precipitation.

ENERGIA E MUDANÇAS CLIMÁTICAS GLOBAIS: PERCEPÇÕES E AÇÕES DO COTIDIANO

POLLINATOR FORAGING STRATEGY IN Galactia peduncularis (BENTH.) TAUB. (LEGUMINOSAE: PAPILIONOIDEA) IN THE PARQUE ESTADUAL DA SERRA DE CALDAS NOVAS BRAZIL The way the animals look for food is an important characteristic of their behavior. The optimal foraging theory is based on the existence of a balance between costs and benefits of these behavioral decisions. The present study aimed to evaluate the behavior of the pollinator in response to increased availability of floral resources. The experiment was conducted in a recently burned Cerrado area (Campo rupestre) in the State Park of Serra de Caldas Novas , located in the municipalities of Caldas Novas and Rio Quente Brazil. The species chosen to test our hypothesis was Galactia peduncularis (Benth.) Taub. (Leguminosae: Papilionoidea). 17 pairs of specimens were selected with a number of flowers, and the individuals of each pair were spaced by about 2m. In these pairs, one of them was considered the focal, and the other, the isolated. To test possible differences in pollination between isolated plants and focus, we performed two randomization tests: a test binary (TB), where all pairs were analyzed and verified the number of times where the focus on the individual floral visits were higher than the number of visits in isolated. According to the data analyzed, floral visitors preferred to use plants that could provide a greater amount of floral resources so that the number of visitors varied positively with the increment of flowers. Plants with many flowers can provide a greater amount of food in one location so that visitors do not need to flower around for long distances in search of meeting their energy needs.