What threat do turbidity currents and submarine landslides pose to strategic submarine telecommunications cable infrastructure?

众所周知，全球经济依赖于海底电信电缆网络的不间断使用。然而，这些海底电缆承载着全球约99%的洲际数字数据流量，因为它们的带宽比卫星大得多。2004年，仅使用这些电报进行的SWIFT银行转账就超过900万笔，每天在208个国家和地区之间进行总计7.4万亿美元的交易。我们对这些电汇的依赖正在增长，例如，去年有1500万笔SWIFT银行交易。因此，海底电缆对英国具有相当大的战略重要性，因为这些数据流量包括互联网、国防信息、金融市场和其他支撑日常生活的服务。这个项目是及时的，因为海底电缆断裂是英国国家风险登记册中一个显著的遗漏。它侧重于行业挑战，即海底电缆究竟为什么、多久以及在哪里因自然原因，主要是海底山体滑坡和沉积物流动(浑浊流)而断裂。这些滑坡和水流可能具有很强的破坏性。1929年的一股气流以19ms-1的速度在东北大西洋折断了11条电缆，向深海延伸了约800公里。如果再发生一次，今天会断掉更多的电缆。由于数据流量不能沿相邻电缆重新路由，因此很难缓解这种流/滑流造成的多次中断。这与拖网捕鱼(或其他人类活动)断掉一根缆绳形成了鲜明对比。这项研究是与全球海洋和国际电缆保护委员会联合进行的。ICPC是海底电缆行业的全球伞形机构，并主办了塔林皇家学会行业联谊会。这将是第一次对电缆断裂及其原因的全球数据库进行统计分析的研究。它将使用新的现场和实验室实验来展示电缆是如何磨损或断裂的。主要项目影响是：(1)我们将向我们的行业合作伙伴(ICPC、个别电缆公司)提供第一个关于电缆断裂频率和原因(地震、台风)的全球统计分析。(2)我们将绘制全球海底网络中最容易受到特定灾害威胁的地理“夹点”；从而帮助我们的合作伙伴设计电缆路线。这些结果将有助于评估未来气候变化最有可能对电缆线路产生影响的地方。(3)实验室实验和新颖的全尺寸现场实验将帮助我们的行业合作伙伴准确地了解海底水流是如何断裂的(以及它们有时无法断裂的原因)。结果将在与个别有线电视公司的研讨会上以及在ICPC的全体会议上介绍。这样的会议将提供一个全球论坛，讨论减少电缆中断的未来战略。(4)将向英国自然灾害伙伴关系和内阁府提交一份简报文件，阐述海底电缆中断是否应包括在英国国家风险登记册中的依据。该项目与多种地理和地质环境以及全球海底通信业具有广泛的相关性。其他类型的昂贵和具有重要战略意义的海底基础设施也容易受到海底流动/滑坡的影响，包括石油和天然气的出口管道和现场流动管道，以及运输化学品、电力和通信的脐带管道。该项目的调查结果将有助于评估海底水流/滑坡对这些其他类型的海底基础设施构成的风险。我们的项目合作伙伴包括那些对用于输送经过处理的水的海底管道(Scottishwater的Carroll)以及全球石油和天然气网络(Jobe、Sylvester、Armitage)风险感兴趣的公司。海底流沉积了沙层，现在形成了许多有价值的石油和天然气储集层。我们还将向感兴趣的合作伙伴(例如壳牌的Jobe、雪佛龙的Sylvester、康菲石油的Armitage)传达我们项目对这些流程的见解。

It is not widely known that the global economy relies on uninterrupted usage of a network of telecommunication cables on the seafloor. Yet these submarine cables carry ~99% of all inter-continental digital data traffic worldwide, as they have far greater bandwidth than satellites. Over 9 million SWIFT banks transfers alone were made using these cables in 2004, totally $7.4 trillion of transactions per day between 208 countries. Our dependence on these cables is growing, for example there were 15 million SWIFT bank transactions last year. Submarine cables thus have considerable strategic importance to the UK because this data traffic includes the internet, defence information, financial markets and other services that underpin daily lives. This project is timely because submarine cable breaks are a notable omission from the UK National Risk Register. It focusses on the industry challenge of why exactly, how often, and where are seafloor cables broken by natural causes, primarily subsea landslides and sediment flows (turbidity currents). These slides and flows can be very destructive. A flow in 1929 travelled at 19 ms-1 and broke 11 cables in the NE Atlantic, running out for ~800 km to the deep sea. A repeat event would break far more cables today. It is difficult to mitigate against multiple breaks from such flows/slides because data traffic cannot be re-routed along adjacent cables. This contrasts with trawling (or other human activities) that break a single cable. This study is in conjunction with Global Marine and the International Cable Protection Committee. The ICPC is the global umbrella body for the submarine cable sector, and hosts Talling's Royal Society Industry Fellowship. This will be the first study to statistically analyse a global database of cable breaks and causes. It will use novel field and laboratory experiments to show how cables abrade or break.The main project impacts are: (1) We will provide our industry partners (ICPC, individual cable companies) with the first global statistical analysis of the frequency and causes (earthquake, typhoons) of cable breaks. (2) We will map geographic "pinch points" in the global seafloor network that are most at risk from specific hazards; thus helping our partners to design cable routes. These results will help to assess where future climate change is most likely to impact upon cable routes. (3) Laboratory experiments and a novel full-scale field experiment will help our industry partners to understand exactly how cables are broken by submarine flows (and why they sometimes fail to break). Results will be presented at workshops with individual cable companies, and at the ICPC's plenary meeting. Such meetings will provide a global forum for discussion of future strategies for reducing cable breaks. (4) A briefing document will be delivered to the UK Natural Hazards Partnership and Cabinet Office that sets out the basis for whether submarine cable breaks should be included in the UK National Risk Register. This project has wide relevance for multiple geographic and geologic settings and the global subsea communications industry. Other type of expensive and strategically important seafloor infrastructure are also susceptible to impacts by submarine flows/slides, including export pipelines and in-field flowline for oil and gas, and umbilicals that transfer chemicals, power and communications. This project's findings will help to assess the risk posed to these other types of subsea infrastructure by submarine flows/slides. Our project partners include those interested in risks to seafloor pipeline used to carry treated water (Carroll at ScottishWater), and oil and gas networks worldwide (Jobe, Sylvester, Armitage). Submarine flows deposit layers of sand that now form many valuable oil and gas reservoirs. We will also communicate insights from our project into these processes to interested partners (e.g. Jobe at Shell, Sylvester at Chevron, Armitage at ConocoPhilips).