Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.
GFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, Germany.
Nature. 2019 Mar;567(7747):229-233. doi: 10.1038/s41586-019-0991-z. Epub 2019 Mar 13.
Waterfalls are inspiring landforms that set the pace of landscape evolution as a result of bedrock incision. They communicate changes in sea level or tectonic uplift throughout landscapes or stall river incision, disconnecting landscapes from downstream perturbations. Here we use a flume experiment with constant water discharge and sediment feed to show that waterfalls can form from a planar, homogeneous bedrock bed in the absence of external perturbations. In our experiment, instabilities between flow hydraulics, sediment transport and bedrock erosion lead to undulating bedforms, which grow to become waterfalls. We propose that it is plausible that the origin of some waterfalls in natural systems can be attributed to this intrinsic formation process and we suggest that investigations to distinguish self-formed from externally forced waterfalls may help to improve the reconstruction of Earth history from landscapes.
瀑布是令人神往的地貌形态，由于基岩的侵蚀作用，它们控制着景观演化的节奏。它们将海平面变化或构造抬升的信息传递到整个景观中，或者阻止河流侵蚀，使景观与下游的干扰相隔离。在这里，我们使用恒定流量和泥沙供给的水槽实验表明，在没有外部干扰的情况下，瀑布可以从一个平面、均匀的基岩床形成。在我们的实验中，水流力学、泥沙输运和基岩侵蚀之间的不稳定性导致了起伏的床形，这些床形逐渐发展成为瀑布。我们提出，在自然系统中，一些瀑布的形成可能归因于这种内在的形成过程，我们建议进行研究来区分自然形成的和外部强迫形成的瀑布，这可能有助于从景观中重建地球历史。
