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

Abstract

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.

Diversity and Effect of Increasing Temperature on the Activity of Methanotrophs in Sediments of Fildes Peninsula Freshwater Lakes, King George Island, Antarctica

“…The positive influence of temperature on the production of CH 4 in sediments of this region was previously verified in microcosm tests ( Ellis-Evans, 1984 ; Vieira et al, 2015 ; Menes and Roldán, 2019 ), consequently, it was important to verify that these sediments could also have the capacity to mitigate CH 4 emissions at higher temperatures.…”

Retrabalhamento de Sedimentos em Bacias Glaciais da Península Fildes, Antártica (Reworking of Sediments in Glacial Basins of The Fildes Peninsula, Antarctica)

“…Na porção norte predominam formas proglaciais associadas à atividade da geleira e formas paraglaciais que já possuem interferência de outros agentes como vento, água de fusão de neve e precipitação líquida. Na porção central, em direção a sul, os ambientes que predominam são periglaciais com processos de erosão não-glacial, movimento de massa nas vertentes, vento, água de fusão da neve e permafrost, e também de precipitação líquida (Vieira et al, 2015).…”

Analysis of Shallow Lake Sediments in the Fildes Peninsula, King George Island, Maritime Antarctica

“…The SCAR KGIS database (VOGT et al, 2004) records 109 lakes on Fildes Peninsula, and Peter et al (2008) record 101 lakes, classifi ed into perennial, permanent and temporary lakes. Vieira et al (2015) proposed a lake classifi cation into proglacial, meltwater, temporary, mixed and wetland.…”