Miocene orographic uplift forces rapid hydrological change in the southern central Andes
- Rainfall in the central Andes associated with the South American Monsoon and the South American Low-Level Jet results from orographic effects on atmospheric circulation exerted by the Andean Plateau and the Eastern Cordillera. However, despite its importance for South American climate, no reliable records exist that allow decoding the evolution of thresholds and interactions between Andean topography and atmospheric circulation, especially regarding the onset of humid conditions in the inherently dry southern central Andes. Here, we employ multi-proxy isotope data of lipid biomarkers, pedogenic carbonates and volcanic glass from the Eastern Cordillera of NW Argentina and present the first long-term evapotranspiration record. We find that regional eco-hydrology and vegetation changes are associated with initiation of moisture transport via the South American Low-Level Jet at 7.6 Ma, and subsequent lateral growth of the orogen at 6.5 Ma. Our results highlight that topographically induced changes in atmospheric circulation patterns, notRainfall in the central Andes associated with the South American Monsoon and the South American Low-Level Jet results from orographic effects on atmospheric circulation exerted by the Andean Plateau and the Eastern Cordillera. However, despite its importance for South American climate, no reliable records exist that allow decoding the evolution of thresholds and interactions between Andean topography and atmospheric circulation, especially regarding the onset of humid conditions in the inherently dry southern central Andes. Here, we employ multi-proxy isotope data of lipid biomarkers, pedogenic carbonates and volcanic glass from the Eastern Cordillera of NW Argentina and present the first long-term evapotranspiration record. We find that regional eco-hydrology and vegetation changes are associated with initiation of moisture transport via the South American Low-Level Jet at 7.6 Ma, and subsequent lateral growth of the orogen at 6.5 Ma. Our results highlight that topographically induced changes in atmospheric circulation patterns, not global climate change, were responsible for late Miocene environmental change in this part of the southern hemisphere. This suggests that mountain building over time fundamentally controlled habitat evolution along the central Andes.…
| Author details: | Alexander Rohrmann, Dirk SachseORCiDGND, Andreas Mulch, Heiko PingelORCiDGND, Stefanie TofeldeORCiDGND, Ricardo N. Alonso, Manfred StreckerORCiDGND |
|---|---|
| DOI: | https://doi.org/10.1038/srep35678 |
| ISSN: | 2045-2322 |
| Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/27767043 |
| Title of parent work (English): | Scientific reports |
| Publisher: | Nature Publ. Group |
| Place of publishing: | London |
| Publication type: | Article |
| Language: | English |
| Year of first publication: | 2016 |
| Publication year: | 2016 |
| Release date: | 2020/03/22 |
| Volume: | 6 |
| Number of pages: | 7 |
| First page: | 4283 |
| Last Page: | 4306 |
| Funding institution: | Deutsche Forschungsgemeinschaft [STR 373/32-1, MU2845/4-1]; DFG-Leibniz Center for Surface Processes and Climate Studies at Universitat Potsdam, Germany [DFG STR 373/18-1]; LOEWE funding program (Landes-Offensive zur of Higher Education, Research, and the Arts; DFG Emmy-Noether grant [SA1889/1-1] |
| Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
| Peer review: | Referiert |
| Institution name at the time of the publication: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Erd- und Umweltwissenschaften |
