Sepulchre Pierre, Ramstein Gilles, Fluteau Frédéric, Schuster Mathieu, Tiercelin Jean-Jacques, Brunet Michel
Laboratoire des Sciences du Climat et de l'Environnement, Institut Pierre-Simon Laplace, UMR 1572, 91191 Gif sur Yvette Cedex, France.
Science. 2006 Sep 8;313(5792):1419-23. doi: 10.1126/science.1129158.
The history of Eastern African hominids has been linked to a progressive increase of open grassland during the past 8 million years. This trend was explained by global climatic processes, which do not account for the massive uplift of eastern African topography that occurred during this period. Atmosphere and biosphere simulations quantify the role played by these tectonic events. The reduced topographic barrier before 8 million years ago permitted a zonal circulation with associated moisture transport and strong precipitation. Our results suggest that the uplift itself led to a drastic reorganization of atmospheric circulation, engendering the strong aridification and paleoenvironmental changes suggested by the data.
东非原始人类的历史与过去800万年中开阔草原的逐渐增加有关。这一趋势被解释为全球气候过程所致，但这些过程无法解释在此期间发生的东非地形大规模隆起。大气和生物圈模拟量化了这些构造事件所起的作用。800万年前之前地形屏障的减少允许了一种纬向环流以及相关的水分输送和强降水。我们的结果表明，隆起本身导致了大气环流的剧烈重组，引发了数据所显示的强烈干旱化和古环境变化。
