Revised paleoaltimetry data show low Tibetan Plateau elevation during the Eocene

Svetlana Botsyun (1, 2) , Pierre Sepulchre (1, 3) , Yannick Donnadieu (1, 3, 4) , Camille Risi (5) , Alexis Licht (6) , Jeremy K. Caves Rugenstein (7, 8)

1 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
2 Eberhard Karls Universität Tübingen = Eberhard Karls University of Tuebingen
3 CLIM - Modélisation du climat
4 CEREGE - Centre européen de recherche et d'enseignement des géosciences de l'environnement
5 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
6 University of Washington [Seattle]
7 ETH Zürich - Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich]
8 Stanford University

Paleotopographic reconstructions of the Tibetan Plateau based on stable isotope paleoaltimetry methods conclude that most of the Plateau's current elevation was already reached by the Eocene, similar to 40 million years ago. However, changes in atmospheric and hydrological dynamics affect oxygen stable isotopes in precipitation and may thus bias such reconstructions. We used an isotope-equipped general circulation model to assess the influence of changing Eocene paleogeography and climate on paleoelevation estimates. Our simulations indicate that stable isotope paleoaltimetry methods are not applicable in Eocene Asia because of a combination of increased convective precipitation, mixture of air masses, and widespread aridity. Rather, a model-data comparison suggests that the Tibetan Plateau only reached low to moderate (less than 3000 meters) elevations during the Eocene, reconciling oxygen isotope data with other proxies.

Domaines: Sciences de l'ingénieur [physics]

Svetlana Botsyun, Pierre Sepulchre, Yannick Donnadieu, Camille Risi, Alexis Licht, et al.. Revised paleoaltimetry data show low Tibetan Plateau elevation during the Eocene. Science, 2019, 363 (6430), pp.946-+. ⟨10.1126/science.aaq1436⟩. ⟨cea-02186564⟩