First detailed synchronous sediment-concentration and velocity data for submarine turbidity currents

第一个详细的海底浊流同步沉积物浓度和速度数据

• 批准号: NE/K011480/2
• 负责人: Peter Talling
• 金额: $ 20.06万
• 依托单位: Durham University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FK011480%2F2
• 关键词: First; detailed; synchronous; sediment; concentration

Submarine sediment density flows ("turbidity currents") and rivers on land are volumetrically the most important processes for moving sediment across our planet. However, submarine flows are more episodic and are typically more violent (with speeds of up to 20m/s) than river floods. Moreover, a single submarine flow is capable of transporting ten times the annual sediment load from all of the world's rivers combined. Submarine flows are important because they produce many of the world's most extensive and voluminous sedimentary deposits, both on the modern sea floor and in the ancient rock record, but also because they can break seafloor cables that now carry over 95% of global data traffic (that underpin our daily lives through the internet and financial markets). Ancient submarine flows created subsurface rock sequences that contain many of our largest oil and gas reserves. Submarine flows carve canyons, which are deeper than the Grand Canyon, through processes that are still poorly understood, and flows within canyons play a key role in supplying organic carbon and nutrients to benthic ecosystem (that include important diversity hotspots) in the deep sea.The most remarkable aspect of submarine density flows is how difficult they are to monitor directly, and how few observations we presently have of such flows in action. This paucity of direct observation provides a stark contrast to the information available for other major sediment transport processes. Changes in the frontal speed of submarine flows have been measured in just five locations, mainly through indirect evidence provided by the timing of sequential underwater cable breaks. Their vertical velocity profile has only ever been measured in three locations and never with sampling rates more frequent than one per hour. No flow has been monitored along its full path, which is of key importance because flows evolve considerably in character along that path.To produce a fundamental step-change in our understanding of submarine flows we need to directly monitor active flows along their entire flow path. Until this is achieved, our understanding of the flow character and its spatial evolution will remain limited. This project will provide by far the most detailed monitoring data yet collected for submarine flows: be the first that places constraints on both dilute and dense near-bed flow components, be the first data set that spans the full flow path, and be the first data set to link measurements of flow processes and the resulting deposit character in such an environment. We aim to conduct a large-scale collaborative program to document and understand sediment transport processes occurring within Monterey Canyon offshore California during an 18-month period in 2014-16, in collaboration with the Monterey Bay Aquarium Research Institute (MBARI) and US Geological Survey (USGS). Such international collaboration is essential for spreading the cost of this ambitious work. MBARI are providing the project with access to a series of innovative tools for monitoring flows that MBARI have designed, built and field tested over the last decade; a contribution worth over $10 Million. This includes aBenthic Instrument Nodes for their Monterey Ocean Observing System that will provide the first high frequency (every 2 to 30 seconds rather than hourly) measurements of 3D velocity, temperature, salinity and density profiles from such flows. MBARI also provide access to the research vessels and ROVs necessary for equipment deployment and servicing during this 18 month period, as MBARI is located at the head of the canyon. MBARI and USGS will place further monitoring equipment in the canyon as part of the project that is worth a further $1.5 Million. Moreover, the MBARI and USGS bear the risk for the loss of all of their equipment. NERC bears a small fraction of the total cost and risk for this unique field experiment, which therefore represents exceptional value for money.

海底沉积物异重流（“浊流”）和陆地上的河流在体积上是在我们的星球上移动沉积物的最重要的过程。然而，海底水流更具有偶发性，通常比河流洪水更猛烈（速度高达20米/秒）。此外，一次海底水流能够输送的泥沙量是世界上所有河流年泥沙量总和的十倍。海底水流之所以重要，是因为它们在现代海底和古代岩石记录中产生了世界上最广泛和最庞大的沉积物，而且还因为它们可以破坏目前承载全球95%以上数据流量的海底电缆（这些数据流量通过互联网和金融市场支撑着我们的日常生活）。古老的海底水流创造了地下岩石序列，其中包含了我们最大的石油和天然气储量。海底水流通过仍然知之甚少的过程雕刻出比大峡谷更深的峡谷，峡谷内的水流在向海底生态系统提供有机碳和营养物方面发挥着关键作用（包括重要的多样性热点）。海底密度流最值得注意的方面是它们是多么难以直接监测，以及我们目前对这种流动的观测是多么的少。直接观测的缺乏与其他主要沉积物迁移过程的现有资料形成鲜明对比。仅在五个位置测量了海底水流前缘速度的变化，主要是通过连续水下电缆断裂的时间提供的间接证据。它们的垂直速度剖面只在三个地点进行过测量，而且采样频率从未超过每小时一次。目前还没有对整个流动路径进行监测，这一点非常重要，因为流动的性质会沿着该路径发生相当大的变化。为了使我们对海底流动的理解发生根本性的变化，我们需要直接监测整个流动路径上的活跃流动。在实现这一点之前，我们对流动特征及其空间演变的理解将仍然有限。该项目将提供迄今为止收集到的最详细的海底水流监测数据：第一个对近床稀流和浓流成分进行限制的数据集，第一个跨越整个水流路径的数据集，第一个将水流过程测量结果与这种环境中产生的存款特征联系起来的数据集。我们的目标是进行一个大规模的合作计划，以记录和了解发生在蒙特雷峡谷近海加州在18个月期间在2014-16沉积物输运过程，与蒙特雷湾水族馆研究所（MBARI）和美国地质调查局（USGS）合作。这种国际合作对于分摊这项雄心勃勃的工作的费用至关重要。MBARI正在为该项目提供一系列创新工具，用于监测MBARI在过去十年中设计、建造和现场测试的流量;捐款价值超过1000万美元。这包括蒙特雷海洋观测系统的一个海底仪器节点，该节点将首次高频（每2至30秒而不是每小时）测量这种流动的三维速度、温度、盐度和密度分布。由于MBARI位于峡谷的顶部，因此在这18个月期间，MBARI还为设备部署和维修所需的研究船和ROV提供通道。MBARI和美国地质勘探局将在峡谷放置更多的监测设备，作为该项目的一部分，该项目价值150万美元。此外，MBARI和美国地质勘探局承担其所有设备损失的风险。NERC承担了这项独特的实地实验的总成本和风险的一小部分，因此代表了资金的特殊价值。

项目成果

Complex and Cascading Triggering of Submarine Landslides and Turbidity Currents at Volcanic Islands Revealed From Integration of High-Resolution Onshore and Offshore Surveys

• DOI: 10.3389/feart.2018.00223
• 发表时间: 2018-09
• 期刊: Frontiers in Earth Science
• 影响因子: 2.9
• 作者: M. Clare;T. Le Bas;D. Price;J. Hunt;D. Sear;M. Cartigny;A. Vellinga;W. Symons;C. Firth;S. Cronin

A General Model for the Helical Structure of Geophysical Flows in Channel Bends

• DOI: 10.1002/2017gl075721
• 发表时间: 2017-12
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: M. Azpiroz-Zabala;M. Cartigny;E. Sumner;M. Clare;P. Talling;D. Parsons;C. Cooper

Which Triggers Produce the Most Erosive, Frequent, and Longest Runout Turbidity Currents on Deltas?

• DOI: 10.1002/2017gl075751
• 发表时间: 2017-12
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: J. Hizzett;J. Clarke;E. Sumner;M. Cartigny;P. Talling;M. Clare

Powerful turbidity currents driven by dense basal layers.

• DOI: 10.1038/s41467-018-06254-6
• 发表时间: 2018-10-05
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Paull CK;Talling PJ;Maier KL;Parsons D;Xu J;Caress DW;Gwiazda R;Lundsten EM;Anderson K;Barry JP;Chaffey M;O'Reilly T;Rosenberger KJ;Gales JA;Kieft B;McGann M;Simmons SM;McCann M;Sumner EJ;Clare MA;Cartigny MJ
• 通讯作者: Cartigny MJ

Newly recognized turbidity current structure can explain prolonged flushing of submarine canyons.

• DOI: 10.1126/sciadv.1700200
• 发表时间: 2017-10
• 期刊: Science advances
• 影响因子: 13.6
• 作者: Azpiroz-Zabala M;Cartigny MJB;Talling PJ;Parsons DR;Sumner EJ;Clare MA;Simmons SM;Cooper C;Pope EL
• 通讯作者: Pope EL