Collaborative Research: Linking landscape evolution and paleoflood hydrology in a megaflood dominated landscape, Channeled Scablands, eastern Washington, USA

冰川湖泊的灾难性排水产生了地球上已知最大的洪水，而这些洪水又雕刻出了引人注目的峡谷景观。华盛顿州东部的沟渠式斯卡伯兰（Channeled Scablands）就是这种景观的一个特例，在上一个冰河时代末期，密苏拉洪水（Missoula洪泛）在这里冲刷了太平洋西北部的大片地区。已知该地区曾发生过多次更早的冰川推进，这可能与它们各自的特大洪水阶段有关。这个项目将调查这些早期的洪水在切割沟渠式结疤地中所起的作用。了解特大洪水是很重要的，因为除了当地的灾难之外，它们还可能改变全球气候。火星上也发生过类似的洪水，了解它们的侵蚀能力是重建火星上洪水规模的关键。该研究区域是美国地质学的主要特征之一，长期以来一直吸引着各种背景的人。它是拟议的冰河时代洪水国家地质小径的所在地，因此将有机会广泛传播科学成果。该项目包括一个教育部分，将培训研究生，并与一个国家认可的项目合作，该项目旨在吸引12-18岁的女孩探索科学、技术、工程和数学。晚更新世冰川溃决洪水在沟槽式结疤地和许多其他景观中造成了巨大的景观变化。然而，对于遭受特大洪水的地形如何随着时间的推移而演变，人们知之甚少，因为它在多次冰川推进期间遭受了反复的洪水。为了解决这一知识缺口，跨学科的研究将被用于重建更新世的水道鞘地景观演变历史。宇宙形成核素表面暴露测年和水力学建模将在沟槽状结疤地的几个地点进行，用于测试关于峡谷形成时间和景观演化的多种假设。这项工作的预期结果是对反复发生灾难性洪水的地形演变的新见解。

Cataclysmic draining of glacial lakes has generated the largest known floods on Earth, and these floods in turn have carved dramatic canyon landscapes. The Channeled Scablands in eastern Washington are an exceptional example of such a landscape, where the Missoula Floods scoured vast tracts of the Pacific Northwest at the end of the last Ice Age. Multiple, earlier glacial advances are known to have occurred in the region, which potentially were associated with their own phases of mega-flooding. This project will investigate the role these earlier floods played in carving the Channeled Scablands. Megafloods are important to understand because, in addition to the local cataclysm, they may have altered global climate. Similar floods also occurred on Mars, and understanding their erosive power is key to reconstructing the size of floods on that planet. The study area is one of the major features of American Geology and has long captivated people from all backgrounds. It is the site of the proposed Ice Age Floods National Geologic Trail, hence there will be opportunities to broadly disseminate the scientific results. The project includes an educational component that will train graduate students and partner with a nationally recognized program designed to engage girls 12-18 years of age in the exploration of science, technology, engineering and mathematics.Late-Pleistocene glacial outburst floods caused dramatic landscape change in the Channeled Scablands and many other landscapes. However, little is known about how the topography of landscapes subjected to mega-floods evolved over time as it was subjected to repeated floods during multiple glacial advances. To address this knowledge gap, an interdisciplinary study will be used to reconstruct the Pleistocene history of Channeled Scablands landscape evolution. Cosmogenic nuclide surface exposure dating and hydraulic modeling at several sites within the Channeled Scablands will be used to test multiple hypotheses concerning the timing of canyon formation and landscape evolution. The expected outcome of this work is new insight into the topographic evolution of landscapes subject to repeated cataclysmic floods.