The presently dry and unglaciated southern Central Andes of northwest Argentina feature a wealth of geomorphic and sedimentological evidence that indicate cooler and/or wetter conditions in the past. Among these are glacial moraines on the highest ranges and lacustrine deposits in the intermontane basins. We use cosmogenic nuclides to date moraines and determine the timings of glaciations associated with
- insolation-driven changes to South American climate, and
- the regional impacts of millennial-scale climate events including the Younger Dryas and the Antarctic Cold Reversal.
Constraining the spatial and temporal patterns of past glaciation in the Andes is essential for advancing our knowledge of South American climate dynamics. In addition, we use physically-based computer models of ice-flow and hydrology to infer former temperature and precipitation values during particular past climate events (e.g., the Younger Dryas). The boundary conditions for the baseline models are derived from global circulation models, satellite data and ground observations. As well as combining field work, geochemistry, glacier- and lake-level modeling, we also work closely with climate modelers and use general climate simulations.
Associates
- Hella Wittmann-Oelze (Earth Surface Geochemistry)
- David Egholm (Aarhus University, Denmark)
- Pedro DiNezio (University of Texas, Austin, USA)
