MACNBR   00242
MUSEO ARGENTINO DE CIENCIAS NATURALES "BERNARDINO RIVADAVIA"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
PATAGONIAN NEOGLACIATIONS: EMERGENCE OF A NEW PATTERN
Autor/es:
MICHAEL KAPLAN ; JORGE STRELIN; JUAN CARLOS ARAVENA; ESTEBAN SAGREDO; JOERG SCHAEFER; ISABEL VILANOVA; SCOTT REYNHOUT; PATRICIO MORENO
Lugar:
Punta Arenas
Reunión:
Congreso; VIII Southern Connection Congress; 2016
Institución organizadora:
Universidad de Magallanes
Resumen:
We present the state-of-the-art knowledge regarding the timing of Holocene glacial fluctuation in southern Patagonia-Tierra del Fuego. We discuss the progress made over the last 10 years, using geomorphic, stratigraphic, and chronologic data. After receding from their advanced Late Glacial positions, Patagonian glaciers were generally close to, or even behind, present ice margins during the Early Holocene. Any glacial advances during this time were relatively minor compared with later expansions; this finding is in agreement with other proxy data that indicate the earliest Holocene was generally a time of warm and dry conditions. Subsequently, we have evidence of multiple millennial timescale glacial advances starting in the middle Holocene. Several glacial maxima are defined by moraines and other landforms from 6,000 years ago to the 19th century, with a gap sometime between 4,500 and 2,500 years ago. The last set of advances began around 700-600 years ago. Although glacial activity is documented in Patagonia at the same time as the European Little Ice Age, the extent of these glacial events are less prominent than those of the mid-Holocene. The causes that may explain these glacial fluctuations remain elusive. One of the challenges is that the Patagonian Neoglaciations occur during times when global CO2 concentrations and the insolation in the mid-latitudes of the Southern Hemisphere are increasing. Here, we explore the hypothesis that centennial timescale climate variability (Southern Annular Mode-like events) could be the main driver of Holocene glacial fluctuation across Patagonia.