A subsurface evacuation model for submarine slope failure
A subsurface evacuation model for submarine slope failure
复制标题
海底边坡破坏的地下疏散模型
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
M. Huuse
中科院分区：
文献类型：
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作者：
S. Bull;J. Cartwright;M. Huuse
对挪威大陆边缘的三维（3D）地震反射数据的分析提供了对一种不寻常的埋藏海底斜坡破坏的深入了解，这种破坏发生在全新世晚期Storegga滑坡附近。已确定的故障，非正式地称为“南Vøring滑动”（SVS），发生在0.5°斜坡上的细粒半远洋和等深岩沉积物中，其特征是变形地震相单元，由紧密间隔的金字塔块体和由垂直于斜坡的小正断层限制的山脊组成。SVS与以前描述的其他海底边坡破坏形成对比，因为它不能用回归模型来解释。定义特征是高相对体积损失。受滑动影响的区域变薄了约40%，与平移方向上非常适度的延伸相结合，线长度平衡产生的延伸值仅为4.5%。体积损失的解释是在装置下部动员了约40 m厚的间隔，并将其从薄覆盖层下方移除，随后进行了延伸破碎。 在大陆边缘环境中海底边坡破坏发展过程中，厚细粒层段活动的证据可能对挪威边缘和全球其他受冰川影响的边缘的其他大规模边坡破坏的起源产生影响。
Analysis of three‐dimensional (3D) seismic reflection data from the Norwegian continental margin provides an insight into an unusual, buried submarine slope failure, which occurred adjacent to the later Holocene‐age Storegga Slide. The identified failure, informally named the ‘South Vøring Slide’ (SVS), occurs in fine‐grained hemipelagic and contourite sediments on a slope of 0.5°, and is characterised by a deformed seismic facies unit consisting of closely spaced pyramidal blocks and ridges bound by small normal faults striking perpendicular to the slope. The SVS contrasts with other previously described submarine slope failures in that it cannot be explained by a retrogressive model. The defining characteristic is the high relative volume loss. The area affected by sliding has thinned by some 40%, seen in combination with very modest extension in the translation direction, with line length balancing yielding an extension value of only 4.5%. The volume loss is explained by the mobilisation of an approximately 40 m thick interval at the lower part of the unit and its removal from beneath a thin overburden, which subsequently underwent extensional fragmentation. Evidence for the mobilisation of a thick fine‐grained interval in the development of a submarine slope failure from a continental margin setting may have implications for the origins of other large‐scale slope failures on the Norwegian margin and other glacially influenced margins worldwide.