A review of glacier fluctuations in southern South America (17°-55°S) during the past millennium

MASIOKAS, M.H.; RIVERA, A.; ESPIZUA, L.E.; VILLALBA, R.; LUCKMAN, B.H.; ARAVENA, J.C.

Conferencia; International Glaciological Conference - Ice and Climate Change; 2010

Centro de Estudios Científicos (CECS)

An updated review of the evidence for glacier fluctuations during the past 1000 years across the extratropical Andes of South America is presented. Information on glacier fluctuations in the Desert Andes (~17°–31°S) is limited to the 20th century. In the Central Chilean-Argentinean Andes (31°–36°S), several glaciers reached their Little Ice Age (LIA) maximum expansion between the 16th and 19th centuries. Further south, in the Patagonian Andes and the Magallanes-Tierra del Fuego regions (36°–55°S), numerous glacier advances have been identified during the past millennium, but precisely dated maximum Little Ice Age (LIA) or post-LIA advances have only been identified at very few sites. The evidence available indicates that the maximum LIA expansion in these regions also occurred between the 16th and 19th centuries, but the data shows considerable variability in the extent and timing of events. A growing body of information is also being collected for glacier advances during the first half of the past millennium. Over the past century many glaciers throughout the extratropical Andes have experienced readvances but these events have not been sufficient to counteract the recent, generalized pattern of thinning and recession. The differences in the glacier histories observed at local and regional scales probably reflect the inherent limitations associated with the glacier records and/or the dating techniques used in each case together with the varying dominance of precipitation, temperature and other climatic and non-climatic factors on glacier mass balance and glacier dynamics. This suggests that the late Holocene glacier history of southern South America is more complex than commonly assumed.