Distal turbidites reveal a common distribution for large (>0.1 km3) submarine landslide recurrence
Distal turbidites reveal a common distribution for large (>0.1 km3) submarine landslide recurrence
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DOI：
10.1130/g35160.1
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发表时间：
2014-03-01
期刊：
影响因子：
5.8
通讯作者：
Hunt, James
中科院分区：
文献类型：
--
作者：
Clare, Michael A.;Talling, Peter J.;Hunt, James
海底滑坡可能比陆地上的滑坡大得多，是在地球上移动沉积物的最重要的过程之一。速度快到足以崩解的山体滑坡可能会产生潜在的非常危险的海啸，并产生长时间的浑浊水流，破坏具有重要战略意义的电缆网络。重要的是要了解它们的频率和触发因素。我们记录了三个盆地平原由大型滑坡(>；0.1公里(3))触发的浊流的重复间隔的分布。尽管不同的年龄和不同的位置，复发间隔的共同分布被观察到，这表明在滑动触发和频率上类似的潜在控制。这种常见的分布非常接近于时间上的随机泊松分布，因此沿盆地边缘发生大规模崩解滑动的概率与自上次滑动以来的时间无关。这种分布表明，海平面等非随机过程并不是这些滑坡频率的主要控制因素。大地震(>；M 7.3)的复发间隔具有近似的泊松分布，这表明它们可能是触发因素。然而，并不是所有的大地震似乎都会产生广泛的浊流，其他未知的触发因素或过程的顺序组合可能会产生相同的分布。这是第一次研究表明，大型滑动触发浊积岩在远端盆地平原具有共同的频率分布，并且这种分布在时间上是随机的。这一结果对评估滑坡-海啸和海底电缆断裂的危害以及全球沉积物通量的长期节奏具有重要意义。
Submarine landslides can be far larger than those on land, and are one of the most important processes for moving sediment across our planet. Landslides that are fast enough to disintegrate can generate potentially very hazardous tsunamis and produce long run-out turbidity currents that break strategically important cable networks. It is important to understand their frequency and triggers. We document the distribution of recurrence intervals for turbidity currents triggered by large landslides (>0.1 km(3)) in three basin plains. A common distribution of recurrence intervals is observed, despite variable ages and disparate locations, suggesting similar underlying controls on slide triggers and frequency. This common distribution closely approximates a temporally random Poisson distribution, such that the probability of a large disintegrating slide occurring along the basin margin is independent of the time since the last slide. This distribution suggests that non-random processes such as sea level are not a dominant control on frequency of these slides. Recurrence intervals of major (>M 7.3) earthquakes have an approximately Poissonian distribution, suggesting they could be implicated as triggers. However, not all major earthquakes appear to generate widespread turbidites, and other as yet unknown triggers or sequential combinations of processes could produce the same distribution. This is the first study to show that large slide-triggered turbidites have a common frequency distribution in distal basin plains, and that this distribution is temporally random. This result has important implications for assessing hazards from landslide-tsunamis and seafloor cable breaks, and the long-term tempo of global sediment fluxes.