open access

https://hdl.handle.net/2115/50876

Glacier mass balance interpreted from biological analysis of firn cores in the Chilean lake district

英語

2008-07

International Glaciological Society

Journal of Glaciology

54(186)

452-462

The first analyses of biological components in glaciers of the Chilean lake district are presented based on microalgae biovolume, pollen and other microorganisms detected in shallow ( 10 m) firn/ice cores. Three cores were retrieved, two at Volca´n Mocho-Choshuenco (398550 S, 728020W; summit at 2422ma.s.l; east glacier at 2000ma.s.l.), and one at the summit of Volca´n Osorno (418060 S, 728300W; 2652ma.s.l.). Microalgae, protozoa and pollen quantified in the samples obtained from the two summit cores show clear fluctuations interpreted as seasonal signs. In contrast, dD and many chemical species from the summit cores show strong dampening at depth, probably due to water percolation. The limited information provided by isotopic and chemical analyses is used to support the seasonal interpretation of biological parameters from the summit cores, with microorganism maxima inferred to occur in summer and pollen maxima in spring. A good comparison is found between massbalance estimations from the Volca´n Mocho-Choshuenco summit core and values obtained near that site by means of the stake method. It is concluded that biological analyses of firn/ice cores provide reliable estimations of annual and seasonal markers from these temperate glaciers.

学術雑誌論文

Version of Record

© 2008 International Glaciological Society

0022-1430

1727-5652

AA0025244X