Relative and radiocarbon chronology of two former glaciers in the Chilean Lake District     

MICHAEL J. BENTLEY 《第四纪科学杂志》1997,12(1):25-33

This paper investigates the relative importance of climatic and topographic factors on the fluctuations of two adjacent palaeoglaciers in the Chilean Lake District. Geomorphological mapping of the landforms around two lakes occupied by the palaeoglaciers has identified a series of intersecting moraine limits and ice-marginal meltwater channels, which allow the relative timing of glacier fluctuations to be established. The broad pattern of advance and retreat is the same in the two basins, with at least one synchronous major advance sometime after 19 500 yr BP, but there is also evidence of discordant behaviour, with one glacier advancing less often and lagging the other glacier during retreat. Seventeen radiocarbon dates suggest a similar chronology to other palaeoglaciers in the Chilean Lake District, but the advance after 19 500 yr BP may have been 1500 ¹⁴C yr later than major advances of palaeoglaciers situated immediately south. The empirical evidence of differential behaviour can be simulated by a glaciological model, which suggests that the differences in glacier response are due to contrasts in basin topography. Contrasts of this magnitude between the timing of some glacier advances has important implications for regional and interhemispheric correlation of Chilean Lake District glacier chronologies to other climate proxy records. © 1997 by John Wiley & Sons, Ltd.  相似文献   

长江三角洲全新世气候变迁     

朱诚  张强 《地理学报(英文版)》2006,16(4):423-429

1 Introduction Global warming and the global-warming-related global environmental problems are receiving increasing attention from scientists, the public and governments of countries. In the coming century anthropological activities may result in further …  相似文献