Geomorphology and geological controls of an active paraglacial rockslide in the New Zealand Southern Alps
Geomorphology and geological controls of an active paraglacial rockslide in the New Zealand Southern Alps
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DOI：
10.1007/s10346-019-01316-2
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发表时间：
2019-12
期刊：
影响因子：
6.7
通讯作者：
Emma Cody;D. Draebing;S. McColl;S. Cook;M. Brideau
中科院分区：
文献类型：
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作者：
Emma Cody;D. Draebing;S. McColl;S. Cook;M. Brideau
地质结构是山坡稳定性的先决条件，也是冰川消融过程和滑坡机制发展的前提。在经历冰川消退和加固的地区，确定滑坡的前提条件是预测滑坡发展的基础。本文描述了新西兰奥拉基/库克山国家公园的~150M m~3Mueller岩滑，并记录了前置条件如何控制其形态和发育，以响应邻近的Mueller冰川变薄。利用基于野外、地球物理和遥感数据的地貌和岩土制图相结合的方法，描述了岩崩和周围山坡的岩体和形态。米勒岩滑被认为是一种岩石复合滑坡，在倾角边坡上经历了主要的平移破坏。岩滑的顶部被几个不连续的阶梯状陡峭所包围，这些陡峭的方向由节理组控制；这些陡峭形成了倾倒的区域，将岩石碎屑输送到主要的岩石滑坡体。冠顶上方的地表和地下不连续测绘发现了许多节理、裂缝和几个陡峭的山崖，这些可能有助于岩崩继续倒退扩大。侧向释放构造的存在、岩滑脚趾的支承和陡峭的层理表明，岩滑可能会演化为快速破坏。
Geological structures precondition hillslope stability as well as the processes and landslide mechanisms which develop in response to deglaciation. In areas experiencing glacier retreat and debuttressing, identifying landslide preconditions is fundamental for anticipating landslide development. Herein, the ~ 150 M m3Mueller Rockslide in Aoraki/Mount Cook National Park, New Zealand, is described; and we document how preconditions have controlled its morphology and development in response to thinning of the adjacent Mueller Glacier. A combination of geomorphological and geotechnical mapping—based on field, geophysical and remote sensing data—was used to characterise the rock mass and morphology of the rockslide and surrounding hillslope. Mueller Rockslide is identified as a rock compound slide, undergoing dominantly translational failure on a dip slope. The crown of the rockslide is bounded by several discontinuous, stepped scarps whose orientation is controlled by joint sets; these scarps form a zone of toppling that is delivering rock debris to the main rockslide body. Surface and subsurface discontinuity mapping above the crown identified numerous joints, fractures and several scarps that may facilitate continued retrogressive enlargement of the rockslide. The presence of lateral release structures, debuttressing of the rockslide toe and steeply dipping bedding suggest that the rockslide may be capable of evolving to a rapid failure.