Climatic Change

, Volume 59, Issue 1, pp 157–175

Glaciers and Climate in the Andes between the Equator and 30° S: What is Recorded under Extreme Environmental Conditions?


  • U. Schotterer
    • Climate and Environmental Physics, Physics InstituteUniversity of Bern
    • Department of Chemistry and BiochemistryUniversity of Bern
  • M. Grosjean
    • Institute of GeographyUniversity of Bern
  • W. Stichler
    • GSF – Institute for Hydrology
  • P. Ginot
    • Byrd Polar Research Center
  • C. Kull
    • Institute of GeographyUniversity of Bern
  • H. Bonnaveira
    • Laboratoire de Glaciologie et de Géophysique de l'EnvironnementInstitute de Recherche pour le Développement (IRD)
  • B. Francou
    • Byrd Polar Research Center
  • H. W. Gäggeler
    • Department of Chemistry and BiochemistryUniversity of Bern
    • Paul Scherrer Institute
  • R. Gallaire
  • G. Hoffmann
    • Laboratoire des Sciences du Climat et de l'Environnement
  • B. Pouyaud
  • E. Ramirez
    • Laboratoire des Sciences du Climat et de l'Environnement
  • M. Schwikowski
    • Paul Scherrer Institute
  • J. D. Taupin

DOI: 10.1023/A:1024423719288

Cite this article as:
Schotterer, U., Grosjean, M., Stichler, W. et al. Climatic Change (2003) 59: 157. doi:10.1023/A:1024423719288


Sublimation and melt disturb the environmental information obtained from ice core records in the Andes. In two case studies we demonstrate to what extent these post-depositional processes may remove major parts of the accumulated snow cover. Dark ash layers from the Tungurahua eruption changed the albedo of surface snow on Chimborazo glacier (6268 m, 1°30′ S,78°36′ W, Ecuador) between two ice core drilling campaigns and forced substantial melt. Re-distribution and washout of the chemical constituents shifted the concentration profiles obtained in December 1999 as compared to an equivalent core drilled in December 2000. The stable isotope records showed that approximately the water equivalent (weq) of an annual layer had melted, and that the percolating melt water penetrated within the firn layer to a depth of at least 16.5 m without refreezing. In the second example, from a site on the dry axis between the tropical and extra-tropical precipitation belts, significant loss of accumulated snow layers occurred by sublimation. A surface experiment at Cerro Tapado glacier (5536 m, 30°08′ S,69°55′ W, Chile) revealed that losses of ≈2 mm weq (≈5 mm snow) per day occurred during the dry period following the 1997/98 El Niño. This loss generally included the entire surface layer enriched in stable isotopes, and thus caused minimal disturbance of the isotopic signature (and hence climatic information) of the net accumulation, yet chemical constituents again experienced considerable changes in concentration. From annual layer counting and direct dating it is obvious that the major part of the accumulated ice on both glaciers is younger than 100 years; however, isotopic and chemical variations at least in the basal ice from Cerro Tapado clearly point to climate conditions different from the recent centuries. This evidence is supported by mass balance considerations derived from a glacier-climate model. The possibility of a third type of disturbance aside from sublimation and melting – in this case a significant hiatus in the environmental chronology – also deserves consideration for other icecore records from this region. Potential disruptions or discontinuities need to be carefully evaluated given the profound changes in climatic and glaciological conditions since the Last Glacial Maximum throughout Holocene times.

Copyright information

© Kluwer Academic Publishers 2003