GSA Connects 2021 in Portland, Oregon

Paper No. 111-1
Presentation Time: 1:35 PM


PELTIER, Carly1, KAPLAN, Michael2, SCHAEFER, Joerg M.3, ARAVENA, Juan Carlos4, SOTERES, Rodrigo L.5 and SAGREDO, Esteban A.5, (1)Lamont-Doherty Earth Observatory, Columbia University, 61 Rte 9W, Palisades, NY 10964, (2)PO Box 1000, 61 Route 9WComer Geochem Building, PO Box 1000, Palisades, NY 10964-8000, (3)Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, (4)Centro de Investigacion Gaia Antartica,, Universidad de Magallanes, Punta Arenas, Chile, (5)Instituto de Geografía, Pontificia Universidad Catolica de Chile, Santiago, Chile

Major questions about the Holocene glacier history of the Southern Hemisphere remain unanswered, and as Earth's most recent geologic Epoch, it represents an important baseline for current glacier and climate change. Glacier chronologies from the Northern Hemisphere generally demonstrate that glaciers became more expansive during the Holocene, culminating in the Little Ice Age advances. Meanwhile, glaciers in New Zealand and southern Patagonia have followed the opposite trend, becoming progressively less extensive through the Holocene, suggesting that the climates of the two hemispheres may have been influenced by different drivers during this period. Given recent advances in the 10Be method, we are now in an excellent position to date precisely and directly the Holocene moraine sequence to the north in Patagonia. In this study we employ recent developments in the method, geomorphic studies, and historical data to reconstruct past Holocene glacier culminations in central Patagonia with unprecedented precision. We find that the Calluqueo glacier record fits the Southern Hemisphere model, with at least 9 glacier stabilization that we date from 6,790 ± 220 years ago to 145 ± 17 years ago. We also bracket the timing of two major periods of glacier retreat during this time, and compare our record with historical data to tie it into the most recent glacier history. This record represents one of the most precise, directly dated records of the Holocene glacier history in Patagonia, in particular in central Patagonia, and sheds light on the potential climate drivers.