The runout of chalk cliff collapses in England and France-case studies and physicalmodel experiments
The runout of chalk cliff collapses in England and France-case studies and physicalmodel experiments
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DOI：
10.1007/s10346-014-0472-2
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发表时间：
2015-04-01
期刊：
影响因子：
6.7
通讯作者：
Take, W. Andrew
中科院分区：
文献类型：
--
作者：
Bowman, Elisabeth T.;Take, W. Andrew
沿海悬崖表面的白垩面从英格兰的约克郡延伸到德文郡，从法国的布龙尼斯延伸到诺曼底。白垩悬崖的崩塌是这些海岸线部分地区长期以来公认的危险；然而，白垩的岩性、地层学和物理性质的变化，加上地形起伏的变化，意味着危险的性质是可变的。本文关注的是可能导致白垩流的悬崖破坏，从而导致灾难性的流滑或类似sturzstorm的行为。本文讨论了白垩流的性质及其与其他类型的流状暴流的关系。最近发表的和未发表的工作被用来统一法国和英国海岸粉笔的简单力学指标性质。然后重新检查一些有充分记录的研究，使用这些结果并根据对sturzstroms的新发现来显示跳动是如何由白垩孔隙度控制的。最后，描述了一系列物理模型试验，其中对粉笔跳动的一些控制进行了检查。
Chalk exposures in coastal cliff faces extend from Yorkshire to Devon in England and from Boulonnais to Normandy in France. The failure of chalk cliffs is a long-recognised hazard along parts of these coastlines; however, variation in the chalk's lithology, stratigraphy and physical properties coupled with changing topographic relief, means that the nature of the hazard is variable. This paper is concerned with cliff failures that may lead to chalk flow resulting in catastrophic flow slide or sturzstrom-like behaviour. The paper discusses the nature of chalk flows and how they relate to other types of flow-like sturzstroms. Recently published and unpublished work is used to unify simple mechanical index properties between the French and English coastal chalks. Some well-documented studies are then re-examined, using these results and in the light of new findings on sturzstroms to show how runout is controlled by chalk porosity. Finally, a series of physical model tests are described in which some of the controls on runout of the chalk are examined.