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

很少有人知道，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SWIFT银行就有900多万笔转账使用这些电缆，每天在208个国家之间的交易总额达7.4万亿美元。我们对这些电缆的依赖越来越大，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明显的遗漏。它关注的是行业面临的挑战，即海底电缆究竟是如何被自然原因（主要是海底滑坡和沉积物流动（浊流））破坏的，以及破坏的频率和位置。这些滑动和流动是非常具有破坏性的。1929年的一股水流速度为每小时19米，在大西洋东北部破坏了11根电缆，流向约800公里的深海。如果事件重演，今天将会有更多的电缆断裂。由于数据流量不能沿着相邻电缆重新路由，因此很难减轻此类流/滑动的多次中断。这与拖网捕鱼（或其他人类活动）破坏单根电缆形成鲜明对比。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，并主办了英国皇家学会行业奖学金。这将是第一个对缆索断裂及其原因的全球数据库进行统计分析的研究。它将使用新颖的现场和实验室实验来展示电缆是如何磨损或断裂的。主要的项目影响是：(1)我们将为我们的行业合作伙伴（ICPC，个别电缆公司）提供第一个全球电缆断裂频率和原因（地震，台风）的统计分析。(2)我们将绘制全球海底网络中最容易受到特定危害的地理“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)实验室实验和全新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电缆是如何被海底水流破坏的（以及为什么它们有时无法断裂）。结果将在个别有线电视公司的研讨会上以及在ICPC的全体会议上公布。这些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办公室提交一份简报文件，阐述海底电缆断裂是否应纳入英国国家风险登记册的基础。该项目与多种地理和地质环境以及全球海底通信行业有着广泛的相关性。其他类型的昂贵且具有重要战略意义的海底基础设施也容易受到海底流动/滑动的影响，包括石油和天然气的出口管道和现场流线，以及输送化学品、电力和通信的脐带缆。该项目的研究结果将有助于评估海底流动/滑动对其他类型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处理水的海底管道风险感兴趣的人（Carroll在ScottishWater），以及全球石油和天然气网络（Jobe, Sylvester, Armitage）。海底流沉积了一层又一层的沙子，这些沙子现在形成了许多有价值的油气储层。我们还将从我们的项目中对这些过程的见解传达给感兴趣的合作伙伴（例如壳牌的Jobe，雪佛龙的Sylvester，康菲石油公司的Armitage）。

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).