Longest sediment flows yet measured show how major rivers connect efficiently to deep sea.
Longest sediment flows yet measured show how major rivers connect efficiently to deep sea.
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DOI：
10.1038/s41467-022-31689-3
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发表时间：
2022-07-20
影响因子：
16.6
通讯作者：
中科院分区：
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在此，我们通过分析地球上实测的（任何类型中）最长的延伸沉积物流，展示了主要河流如何有效地与深海相连。这些海底浊流源自刚果河河口，其中一股流动距离超过1130千米，同时速度从5.2米/秒加速到8.0米/秒。一年内，这些浊流从一条海底峡谷侵蚀了1338 - 2675[>535 - 1070]百万吨沉积物，相当于当今河流年悬浮沉积物通量的19 - 37[>7 - 15]%。已知地震会引发峡谷冲刷流。我们表明河流洪水也会产生峡谷冲刷流，这是由河口处的快速沉积物堆积引发的，有时是在洪水过后数周乃至数月由大潮触发的。研究表明，强侵蚀性浊流会自我加速，从而传播得更远，这验证了一个长期提出的理论。这些观测结果解释了高效的有机碳转移，并且对海底电缆面临的危害或陆地气候变化对深海的影响具有重要意义。
本文分析了地球上实测的最长的沉积物流。这些海底流是由洪水和大潮引起的，并且在加速流动一千千米的过程中，将大量的沉积物和碳冲刷到深海中。
Here we show how major rivers can efficiently connect to the deep-sea, by analysing the longest runout sediment flows (of any type) yet measured in action on Earth. These seafloor turbidity currents originated from the Congo River-mouth, with one flow travelling >1,130 km whilst accelerating from 5.2 to 8.0 m/s. In one year, these turbidity currents eroded 1,338-2,675 [>535-1,070] Mt of sediment from one submarine canyon, equivalent to 19–37 [>7–15] % of annual suspended sediment flux from present-day rivers. It was known earthquakes trigger canyon-flushing flows. We show river-floods also generate canyon-flushing flows, primed by rapid sediment-accumulation at the river-mouth, and sometimes triggered by spring tides weeks to months post-flood. It is demonstrated that strongly erosional turbidity currents self-accelerate, thereby travelling much further, validating a long-proposed theory. These observations explain highly-efficient organic carbon transfer, and have important implications for hazards to seabed cables, or deep-sea impacts of terrestrial climate change. This paper analyses the longest sediment flows measured in action on Earth. These seabed flows were caused by floods and spring tides, and flushed prodigious sediment and carbon volumes into the deep sea, as they accelerated for a thousand kilometres.
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DOI：
10.1016/j.dsr2.2017.03.010
发表时间：
2017-08-01
影响因子：
3
作者：
Dennielou, Bernard;Droz, Laurence;Rabouille, Christophe
通讯作者：
Rabouille, Christophe
影响因子：
4.2
作者：
Babonneau, N;Savoye, B;Klein, B
通讯作者：
Klein, B
影响因子：
2.9
作者：
HEEZEN, BC;EWING, M
通讯作者：
EWING, M
影响因子：
64.8
作者：
Galy, Valier;France-Lanord, Christian;Palhol, Fabien
通讯作者：
Palhol, Fabien
影响因子：
16.6
作者：
Heijnen, Maarten S.;Clare, Michael A.;Clarke, John E. Hughes
通讯作者：
Clarke, John E. Hughes