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.

海底沉积物密度流（“浊度流”）和陆地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（速度可达20米/秒）。此外，一条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。海底流很重要，因为它们在现代海底和古代岩石记录中产生了许多世界上最广泛、体积最大的沉积物，而且还因为它们可以破坏海底电缆，这些电缆现在承载着全球95%以上的数据流量（通过互联网和金融市场支撑着我们的日常生活）。古老的海底流动创造了地下岩石序列，其中包含许多我们最大的石油和天然气储量。海底水流雕刻出比大峡谷更深的峡谷，其过程仍然知之甚少，峡谷内的水流在向深海底栖生态系统（包括重要的多样性热点）提供有机碳和营养物质方面发挥着关键作用。海底密度流最引人注目的方面是直接监测它们是多么困难，而我们目前对这种流动的观察是多么少。这种直接观测的缺乏与其他主要泥沙输运过程的现有信息形成鲜明对比。仅在五个地点测量了海底水流的锋面速度变化，主要是通过连续水下电缆断裂时间提供的间接证据。它们的垂直速度剖面只在三个地点测量过，采样频率从未超过每小时一次。没有沿着它的整个路径监测流动，这是至关重要的，因为沿着这条路径流动的特征发生了很大的变化。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动流。在此之前，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流动监测数据：是第一个对稀释和密集的近床流成分进行限制的数据集，是第一个跨越整个流动路径的数据集，是第一个将流动过程的测量与这种环境下的沉积特征联系起来的数据集。我们的目标是与蒙特利湾水族馆研究所（MBARI）和美国地质调查局（USGS）合作，在2014- 2016年的18个月期间，开展一项大规模的合作项目，记录和了解加州近海蒙特利峡谷的沉积物运输过程。这种国际合作对于分摊这项雄心勃勃的工作的成本至关重要。MBARI为该项目提供了一系列创新的流量监测工具，这些工具是MBARI在过去十年中设计、制造和现场测试的。价值超过一千万美元的捐款这包括他们的蒙特雷海洋观测系统的aBenthic仪器节点，该系统将提供第一次高频（每2到30秒而不是每小时）测量这些流的3D速度，温度，盐度和密度剖面。由于MBARI位于峡谷的顶端，在这18个月的时间里，MBARI还为设备部署和维修提供了必要的研究船和rov。作为价值150万美元的项目的一部分，MBARI和USGS将在峡谷中放置进一步的监测设备。此外，MBARI和USGS承担所有设备损失的风险。NERC承担了这一独特现场试验总成本和风险的一小部分，因此具有极高的性价比。

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

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

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