Large Submarine Landslides on Continental Slopes: Geohazards, Methane Release, and Climate Change
Large Submarine Landslides on Continental Slopes: Geohazards, Methane Release, and Climate Change
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DOI：
10.5670/oceanog.2014.38
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发表时间：
2014-06
期刊：
影响因子：
2.8
通讯作者：
P. Talling;M. Clare;M. Urlaub;E. Pope;J. Hunt;S. Watt
中科院分区：
文献类型：
--
作者：
P. Talling;M. Clare;M. Urlaub;E. Pope;J. Hunt;S. Watt
在开阔的大陆斜坡上的海底滑坡可能规模巨大。它们是全球沉积物通量的一个重要过程，并可能产生非常具有破坏性的海啸。海底滑坡比陆地滑坡更难直接监测，其前置因素和触发因素的不确定性也大得多。海底边坡破坏通常发生在非常低（< 2°）的坡度上，而这些坡度在陆地上几乎总是稳定的，这表明必须涉及特别高的超孔隙压力。地震会引发一些大型海底滑坡，但并不是所有的大地震都会导致大面积的滑坡。许多大型海底滑坡的头壁似乎位于水深太深，无法由天然气水合物解离引发。现有的证据表明，山体滑坡的发生与海平面或大气甲烷丰度的变化之间的联系要么很弱（要么没有），要么是开放大陆斜坡滑坡的现有日期太不精确，无法判断。同样，现有的证据也不能有力地支持这样一种观点，即山体滑坡在导致气候变化的甲烷排放中起着重要作用。然而，规模最大、年代最准确的开放大陆斜坡滑坡（斯托尔加滑坡）与8200年前的一次主要降温事件同时发生。这种联系表明，在声明大型露天滑坡与气候变化之间没有联系时，可能需要谨慎。
Submarine landslides on open continental slopes can be prodigious in scale. They are an important process for global sediment fluxes, and can generate very damaging tsunamis. Submarine landslides are far harder to monitor directly than terrestrial landslides, and much greater uncertainty surrounds their preconditioning factors and triggers. Submarine slope failure often occurs on remarkably low (< 2°) gradients that are almost always stable on land, indicating that particularly high excess pore pressures must be involved. Earthquakes trigger some large submarine landslides, but not all major earthquakes cause widespread slope failure. The headwalls of many large submarine landslides appear to be located in water depths that are too deep for triggering by gas hydrate dissociation. The available evidence indicates that landslide occurrence is either weakly (or not) linked to changes in sea level or atmospheric methane abundance, or the available dates for open continental slope landslides are too imprecise to tell. Similarly, available evidence does not strongly support a view that landslides play an important role in methane emissions that cause climatic change. However, the largest and best-dated open continental slope landslide (the Storegga Slide) coincides with a major cooling event 8,200 years ago. This association suggests that caution may be needed when stating that there is no link between large open slope landslides and climate change.