Predicting turbidity current activity offshore from meltwater-fed river deltas
Predicting turbidity current activity offshore from meltwater-fed river deltas
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DOI：
10.1016/j.epsl.2022.117977
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发表时间：
2023-02
影响因子：
5.3
通讯作者：
L. Bailey;M. Clare;E. Pope;I. Haigh;M. Cartigny;P. Talling;D. Lintern;S. Hage;M. Heijnen
中科院分区：
文献类型：
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作者：
L. Bailey;M. Clare;E. Pope;I. Haigh;M. Cartigny;P. Talling;D. Lintern;S. Hage;M. Heijnen
需要对浊流复发的控制进行量化，以更好地限制沉积物、碳和污染物的陆地入海通量，并设计易受此类流动影响的弹性基础设施。这一点在河流三角洲的近海尤为重要，因为那里的沉积物供应量很高。许多机制可以触发浊流，即使在一个单一的河口。然而，由于精确定时（通过直接监测）流量的数量很少，因此复发和触发的定量分析仅限于每个浊流的单个触发。因此，我们还没有量化是否以及如何同步过程联合收割机组合，以产生浊流，以及它们的相对重要性。本文分析了一条海底通道中113条直接监测到的浊流从浊流形成源到沉积汇的时间和成因。这条海底通道位于加拿大不列颠哥伦比亚省的一个峡湾布特湾的冰川河流三角洲的近海。使用多元统计方法，我们证明了2018年期间河流流量和潮汐控制对浊流发生的统计意义，从中我们推导出一个统计模型，该模型计算了任何给定河流流量和水位输入的浊流概率。该新模型预测浊流活动的成功率>84%，在其他河流三角洲，流量时间受到直接监测的精确限制，包括不列颠哥伦比亚省的斯夸米什米什和弗雷泽河三角洲。我们建议，该模型将适用于浊流预测在全球许多其他地区的冰川融水喂养峡湾。
Quantification of the controls on turbidity current recurrence is required to better constrain land to sea fluxes of sediment, carbon and pollutants, and design resilient infrastructure that is vulnerable to such flows. This is particularly important offshore from river deltas, where sediment supply is high. Numerous mechanisms can trigger turbidity currents, even at a single river mouth. However quantitative analysis of recurrence and triggers has been limited to an individual trigger for each turbidity current due to the low number of precisely timed (via direct monitoring) flows. We are therefore yet to quantify if and how coincident processes combine to generate turbidity currents, and their relative importance. Here, we analyse the timing and causes of 113 turbidity currents directly-monitored from the source of turbidity current initiation to depositional sink in a single submarine channel. This submarine channel is located offshore from glacial-fed river-deltas at Bute Inlet, a fjord in British Columbia, Canada. Using a multivariate statistical approach, we demonstrate the statistical significance of combined river discharge and tidal controls on turbidity current occurrence during 2018, from which we derive a statistical model that calculates turbidity current probability for any given input of river discharge and water level. This new model predicts turbidity current activity with >84% success offshore other river deltas where flow timing is precisely constrained by directly monitoring, including the Squamish and Fraser River-deltas in British Columbia. We suggest that this model will be applicable for turbidity current prediction at glacial meltwater-fed fjords in many other regions worldwide.