Little Ice Age fluctuations of small glaciers in the Monte Fitz Roy and Lago del Desierto areas, south Patagonian Andes, Argentina

MASIOKAS, M.H.; LUCKMAN, B.H.; VILLALBA, R.; DELGADO,S.; SKVARCA, P.; RIPALTA, A.

PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY

Elsevier

Lugar: Jena; Año: 2009 vol. 281 p. 351 - 362

0031-0182

Current knowledge about late Holocene glacier fluctuations in the south Patagonian Andes is mainly based on  evidence from large outlet glaciers of the North and South Patagonian Icefields, and fewdata exist for the smaller  glaciers elsewhere in the region. Here we provide dendrogeomorphological evidence for Little Ice Age (LIA) and post-LIA activity for five small glaciers near the northeast margin of the South Patagonian Icefield. The study sites  include Glaciar Torre and Piedras Blancas in the Monte Fitz Roy area, and three adjacent glaciers near Lago del Desierto.At these sites the LIAmaximumpositionwas identified bymassivemoraineswithmature trees dating to  the late 1500s–early 1600s. Several older moraineswere observed beyond these limits but could not be precisely  dated. Relatively synchronous advances occurred at most glaciers in the early 1700s and were dated using living trees and in situ, subfossil material. All glaciers show three to five subsequent advances mostly concentrated  between the mid-19th and early 20th centuries. Estimates based on Landsat TM imagery indicate these glaciers lost between 15 and 46% of their LIA areas by 1984 and a further 5–18% by 2005, with the smallest glaciers  showing the greatest proportional loss. Paired comparisons of contemporary and the earliest knownphotography for the glaciers in the Fitz Roy area confirmthismass loss. These results provide important newinformation on the  glacier history of this area but additional, more precisely-dated records are needed from many more sites before we can fully elucidate the complex late Holocene glacial history of this region.