Spatial and Paleoclimatic Reconstruction of the Peña Negra Paleoglacier (Sierra de Béjar-Candelario, Spain) during the Last Glacial Cycle (Late Pleistocene)

Abstract

The study of the Peña Negra paleoglacier during the Last Glacial Maximum reveals its sensitivity to paleoclimatic variations. The evolutionary phases of the paleoglacier are correlated with the evolutionary models proposed for the Sierra de Béjar-Candelario and the Central Iberian System. To recognize the mechanisms of ice advance/retreat and the response of the glacier to paleoclimatic variations, modeling is carried out based on a geographic information system tool. This model is key to establishing the spatial extent of the ice and the estimation of the Equilibrium line altitudeequilibrium line altitudes at each moment, which makes it easier to infer the approximate climatic conditions of each phase (temperature and precipitation) and allows us to improve the understanding of the glacial dynamics versus variations in paleoenvironmental conditions and paleoglacial morphometry. The spatial reconstruction data show that the paleoglacier had 0.526 km3 of ice during the phase of maximum extension, while the paleoclimatic data reflect an increase in precipitation and a slight decrease in average summer temperatures compared to today. The stability phases are associated with the periods of greatest precipitation when the mass balance was positive.