Journal cover Journal topic
Climate of the Past An interactive open-access journal of the European Geosciences Union
doi:10.5194/cp-2016-89
© Author(s) 2016. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
14 Sep 2016
Review status
This discussion paper is under review for the journal Climate of the Past (CP).
The Last Glacial Termination on the eastern flank of the central Patagonian Andes (47° S)
William I. Henríquez1,2, Rodrigo Villa-Martínez3, I. Vilanova4, R. De Pol-Holz3, and P. Moreno2 1Victoria University of Wellington, Wellington, New Zealand
2Instituto de Ecología y Biodiversidad, Departamento de Ciencias Ecológicas, Universidad de Chile, Casilla 653, Santiago, Chile
3GAIA-Antártica, Universidad de Magallanes, Avda. Bulnes 01855, Punta Arenas, Chile
4Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Avda. Angel Gallardo 470, Buenos Aires, Argentina
Abstract. Few studies have examined in detail the sequence of events during the last glacial termination (T1) in the core sector of the Patagonian Ice Sheet (PIS), the largest ice mass in the southern hemisphere outside Antarctica. Here we report results from Lago Edita (47°8' S, 72°25' W, 570 m.a.s.l.), a small closed-basin lake located in a valley overridden by eastward-flowing Andean glaciers during the Last Glacial Maximum (LGM). Lago Edita shows glaciolacustrine sedimentation until 19,400 yr BP and a mosaic of cold-resistant, hygrophilous conifers and rainforest trees, along with alpine herbs between 11,000-19,400 yr BP. Increases in arboreal pollen at 13,200 and 11,000 yr BP led to the establishment of forests near Lago Edita between 9000–10,000 yr BP. Our data suggest that the PIS retreated at least ~90 km from its LGM limit between ~19,400–21,000 yr BP and that scattered, low-density populations of cold-resistant hygrophilous conifers, rainforest trees, high Andean and steppe herbs thrived east of the Andes during the LGM and T1, implying high precipitation and SWW intensity at 47° S. We interpret large-magnitude increases in arboreal vegetation as treeline-rise episodes driven by warming pulses at 13,200 and 11,000 yr BP coupled with a decline in SWW influence at ~11,000 yr BP, judging from the disappearance of cold-resistant hygrophilous trees and herbs. We propose that the PIS imposed a regional cooling signal along its eastern, downwind margin through T1 that lasted until the separation of the North and South Patagonian icefields along the Andes. We posit that the withdrawal of glacial and associated glaciolacustrine environments through T1 provided a route for the dispersal of hygrophilous trees and herbs from the eastern flank of the central Patagonian Andes, contributing to the afforestation of the western Andean slopes and pacific coasts of central Patagonia during T1.

Citation: Henríquez, W. I., Villa-Martínez, R., Vilanova, I., De Pol-Holz, R., and Moreno, P.: The Last Glacial Termination on the eastern flank of the central Patagonian Andes (47° S), Clim. Past Discuss., doi:10.5194/cp-2016-89, in review, 2016.
William I. Henríquez et al.
William I. Henríquez et al.
William I. Henríquez et al.

Viewed

Total article views: 385 (including HTML, PDF, and XML)

HTML PDF XML Total BibTeX EndNote
282 59 44 385 4 44

Views and downloads (calculated since 14 Sep 2016)

Cumulative views and downloads (calculated since 14 Sep 2016)

Viewed (geographical distribution)

Total article views: 385 (including HTML, PDF, and XML)

Thereof 383 with geography defined and 2 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 29 May 2017
Publications Copernicus
Download
Short summary
The Lago Edita (47°8' S, 72°25' W) record shows a mosaic of cold-resistant, hygrophilous rainforest trees and alpine herbs between 11,000–19,400 yr BP, suggesting cold and wet conditions during the last glacial termination. We interpret increases of arboreal pollen at 13,200 and 11,000 yr BP as treeline-rise episodes driven by warming, and observe that deglacial warming in Lago Edita lagged behind sites located along the western Andean slopes. We discuss a likely origin for this delayed warming.
The Lago Edita (47°8' S, 72°25' W) record shows a mosaic of cold-resistant, hygrophilous...
Share