Submarine landslides: processes, triggers and hazard prediction
Submarine landslides: processes, triggers and hazard prediction
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DOI：
10.1098/rsta.2006.1810
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发表时间：
2006-08-15
期刊：
影响因子：
5
通讯作者：
Lovholt, F.
中科院分区：
文献类型：
--
作者：
Masson, D. G.;Harbitz, C. B.;Lovholt, F.
巨大的滑坡，动员数百至数千公里3的沉积物和岩石是无处不在的海底设置，从最陡峭的火山岛斜坡到海底三角洲最温和的泥泞斜坡。在这里，我们总结了目前的知识，这样的滑坡和评估其潜在危害的问题。与海底滑坡有关的主要危害包括破坏海底基础设施、沿海地区坍塌入海以及滑坡引发的海啸。大多数海底斜坡本质上是稳定的。孔隙压力升高（导致滑动摩擦阻力降低）和层状序列中的特定软弱层似乎是影响滑坡发生的关键因素。孔隙压力升高可能是由于正常的沉积过程或地震震动等瞬态过程造成的;历史证据表明，大多数大型海底滑坡都是由地震引发的。由于其潜在的海啸，海洋岛屿侧翼坍塌和峡湾中的岩石滑坡已被确定为所有滑坡相关灾害中最危险的。已发表的海岛滑坡模型主要研究发生概率较低的“最坏情况”。容易发生海底滑坡的区域相对容易识别，但我们仍有一段距离能够准确预测个别事件。对可能即将发生滑坡的关键地区进行监测，并对滑坡后果进行建模，以便制定适当的缓解战略，这似乎是目前做法有可能取得进展的领域。
Huge landslides, mobilizing hundreds to thousands of km 3 of sediment and rock are ubiquitous in submarine settings ranging from the steepest volcanic island slopes to the gentlest muddy slopes of submarine deltas. Here, we summarize current knowledge of such landslides and the problems of assessing their hazard potential. The major hazards related to submarine landslides include destruction of seabed infrastructure, collapse of coastal areas into the sea and landslide-generated tsunamis. Most submarine slopes are inherently stable. Elevated pore pressures (leading to decreased frictional resistance to sliding) and specific weak layers within stratified sequences appear to be the key factors influencing landslide occurrence. Elevated pore pressures can result from normal depositional processes or from transient processes such as earthquake shaking; historical evidence suggests that the majority of large submarine landslides are triggered by earthquakes. Because of their tsunamigenic potential, ocean-island flank collapses and rockslides in fjords have been identified as the most dangerous of all landslide related hazards. Published models of ocean-island landslides mainly examine 'worst-case scenarios' that have a low probability of occurrence. Areas prone to submarine landsliding are relatively easy to identify, but we are still some way from being able to forecast individual events with precision. Monitoring of critical areas where landslides might be imminent and modelling landslide consequences so that appropriate mitigation strategies can be developed would appear to be areas where advances on current practice are possible.