USC0033
Written evidence submitted by the National Oceanography Centre
The UK’s National Oceanography Centre (NOC) is one of the world’s leading ocean scientific research and technological institutions, with a remit to deliver research from the coast to the deep sea. We are an independent research organisation, with charitable status. We were formally part of the Natural Environmental Research Council (NERC), which is part of UK Research and Innovation, until 2019.
We undertake and facilitate world-class, agenda-setting scientific research and technology development to understand the ocean, which in turn underpins international and UK public policy, business and societal outcomes. We are in a unique position of having world-leading multi-disciplinary scientific and technical expertise, including on sea-level changes, coastal hazards and resilience.
NOC operates the Royal Research Ships James Cook and Discovery and develops technology for coastal and deep ocean research, including autonomous vehicles and sensors, which can be used to explore the oceans and collect data, to better understand and monitor marine environments. Working with our partners, we provide long-term marine science capability including sustained ocean observations, mapping and surveying, data management, scientific research and advice.
Among the resources that we provide on behalf of the UK are the British Oceanographic Data Centre (BODC), the Marine Autonomous and Robotic Systems (MARS) facility, the National Tide and Sea Level Facility (NTSLF), the Permanent Service for Mean Sea Level (PSMSL) and British Ocean Sediment Core Research Facility (BOSCORF).
The resilience of the undersea cable infrastructure and the ways undersea cables can be used to monitor our ocean is an important area of study for our scientists and technology experts. When the first subsea telegraph cables were laid in the 1850s, the observations from the related surveys and laying operations provided important new insights into the ocean – discovering the presence of a ridge in the middle of the Atlantic Ocean, the first evidence of complex life in the deep sea, and that underwater landslides can runout far into the deep ocean, damaging cables. More than 150 years on, we continue to learn about ocean and Earth processes from information gleaned from cable installation, recovery and repair operations. For example, how tropical cyclones are shifting their focus towards the poles (as evidenced by repeated cable damage offshore Taiwan), how volcanic eruptions can generate major underwater sediment flows that can travel for 100s of km (as shown offshore Tonga in 2022), how river floods can flush large volumes of sediment and organic carbon into the deep-sea (e.g., revealed by damage to subsea cables offshore West Africa in 2020), and the rate at which seafloor ecosystems recover after cables have been buried for their protection. In more recent years, technological developments now enable the optical fibres that lie at the core of modern telecommunications cables to be used as sensors to detect temperature changes, detect earthquakes, provide early warning for tsunamis, and even monitor whale and dolphin calls. Research at the NOC continues to better understand the hazards for subsea cables that are evolving due to climate change, to provide evidence to ensure that such systems are installed and maintained in the most environmentally-sensitive manner, and to potentially use the global network to better understand a wide range of processes in the ocean.
1. How might the UK’s reliance on undersea cables evolve over the next 10-15 years?
With over 99% of global data transfer and international communications being dependent on undersea cables, the threats to this infrastructure are a global concern and the UK isn’t immune to them. Although malicious sabotage is a possible cause of cable damage, evidence from past instances of cable damage reveals that >70% relates to inadvertent interactions with fishing gear or ships’ anchors. Depending on the location, natural hazards (including underwater landslides, sediment avalanches, storms, seafloor currents or volcanic eruptions) can account for 10-20% of cable damage. While natural hazards account for a smaller proportion, they are important as they can affect multiple cable systems synchronously, across extremely large areas, limiting rerouting of data traffic by other systems.
Some of the examples of undersea cables being impacted by weather events include, for example, storm surges in 2012 knocking out internet connections in New York, tropical cyclones offshore Taiwan in 2009 halting financial trading, and extreme river flooding triggering offshore sediment flows and ‘crippled’ internet connections across West Africa during 2020’s COVID-19 lockdown.
Locations with few cable connections are most vulnerable to outages. In 2022, the eruption of Hunga volcano offshore Tonga triggered powerful seafloor flows that severed Tonga’s only international cable, effectively cutting off an entire country from the internet. The UK has many cable connections and hence is far more reliable than nations such as Tonga as a result of its geographic diversity of routes and landing stations. Islands may be more vulnerable, however, as evidenced by damage to two critical cables, which disconnected the Shetland Islands in 2022 (due to an interaction with fishing gear) and a near-miss in the Channel Islands in 2016, where multiple cables were damaged by an unintentional anchor drag during a storm.
Conditions are changing and this needs to be considered carefully. The risks to seafloor cable infrastructure are likely to intensify, diversify and impact new locations under future climate change scenarios, creating previously unanticipated hazards. Previously considered resilient routes may experience new hazards, and co-located cables may be vulnerable to hazards such as storms.
It is critical to not just consider impacts on subsea components of the network. Sea-level rise is expected to have the most direct and immediate impact on subsea infrastructure, notably landing stations. Many are built close to coastlines, and some are not much higher than current sea levels. Therefore, continuous sea-level rise, directly linked with the changing global climate, potentially puts this infrastructure and infrastructure on the beach (e.g., beach manholes) at direct risk. Sustained impacts of storms, currents and coastal erosion may lead to progressive damage, rather than one-off instantaneous events.
A growing need for more cables to satisfy end user demand means that new routes will be considered, or may be co-located close to each other, which poses potential threats (e.g., due to limited geographic diversity).
It is worth noting that this response is primarily focused on fibre optic telecommunications cables and not power cables (i.e. that connect to offshore renewables sites or that convey power between countries). Such cables are more challenging to repair.
These potential sources of damage are possible everywhere, however the risk arguably is greater for smaller island nations, such as Tonga. This is because they are more likely to rely on a single cable providing all their connectivity and are more exposed to natural hazards such as earthquakes or volcanic eruptions. The UK is far better served by cables in comparison, making it far more resilient; however, as mentioned above, island communities (e.g., Shetlands or the Channel Islands) are more vulnerable.
Human activities will continue to be a significant issue for subsea cables in UK and surrounding waters, given the intensity of maritime activities, which is greater than many other areas. For example, the Caribbean and South Pacific experience relatively limited fishing-related cable damage due to the water depths and less intensive fishing activity. The UK’s waters, and those for many of the cables that connect it, are fished heavily and traversed by abundant maritime traffic; hence, fishing and anchoring are the primary causes of cable damage and will continue to be so.
At this time, undersea cables provide the best and most comprehensive global connection, despite any potential risk of damage. Low level satellites provide useful back-up, and serve remote communities on islands etc; hence, such technology will be a contributory factor but cannot currently address the requirements of data capacity.
3. What developments are expected in subsea technologies over the next 10 years?
The UK is very well placed to capitalise on the advances in sensing capabilities using fibre-optic cables as it has strong expertise in the areas of optics, photonics and environmental sensing.
The NOC has been instrumental in providing access to UK government with regards to the latest state of technology, challenges and opportunities surrounding use of fibre-optic cables for ocean sensing, having contributed briefings to cross-departmental meetings with Department of Science, Innovation and Technology (DSIT), Department of Environment, Food and Rural Affairs (Defra), , Defence, Science and Technology Laboratory (DSTL), Ministry of Defence (MoD) , Cabinet Office and The Crown Estate.
New UK funded programmes such as Advanced Research and Invention Agency (ARIA) have recently supported projects that will make use of in-service telecommunications cables to monitor ocean conditions and climate change. This includes a new NOC-led £2M project called FullOceanFibre that will use in service seafloor cables to monitor conditions in the North Atlantic Ocean, as noted here: https://noc.ac.uk/news/noc-awarded-11m-climate-tipping-point-early-warning-systems-research
6. How well is policy and co-ordination working across Whitehall departments, law enforcement and private sector actors? Are any changes needed?
There have been significant positive efforts over the past couple of years to enhance and improve policy coordination, particularly as greater interest has been shown in this sector than ever before. DSIT, the telecoms resilience team of which was formerly part of the Department for Digital, Culture, Media and Sport) has spearheaded initiatives to bring together discussions from researchers (e.g., NOC), industry (companies, but particularly organisations such as the European Subsea Cables Association (that has Observer Status in the OSPAR Commission), International Cable Protection Committee (that has Observer status at the United Nations)), and widen out discussions with other stakeholders such as The Crown Estate, Crown Estate Scotland, Joint Nature Conservation Committee (JNCC), Natural England, the Cabinet Office, MoD, DSTL, and Defra to name a few. This has been largely conducted on an ad-hoc basis and is still a work in progress as people change across those organisations regularly. Stronger formalisation of these relationships would be useful, particularly to ensure that responses to urgent queries or issues can be coordinated (e.g., rapid attribution of cable damage to natural hazards to rule out bad actors etc) or where emergent topics gain traction across multiple departments (e.g., dual use of fibre optic cables for monitoring and situational awareness). This should save in duplication of effort and will make sure that the Government can most effectively coordinate and bring together the most appropriate people and has evidence to the latest evidence.
There is regularly interaction between Government at industry events such as the ICPC Plenary, Submarine Networks EMEA, ESCA Plenary, Valentia cable resilience symposium, and others. These events are useful, but there is value in a more formalised ‘cluster’ of stakeholders that could be called upon as and when needed, and to motivate future research and direct funding in the most useful manner. A more strategic, coordinated and formal approach, cross-departmentally and bringing together key industry and science stakeholders, is therefore necessary for the UK to improve UK’s position in this area. NOC has been delighted to work closely with Government by providing important scientific and expert research, and we look forward to continuing our strong working relationship with Government and urge for greater joined-up thinking in Government on this issue.
10 March 2025
Further resources:
The primary contacts within the NOC for understanding and assessing hazards to subsea cables, and their environmental interactions are Dr Michael Clare and Dr Isobel Yeo.
Please see some NOC Publications that are relevant to better understand cable security and protection below:
Natural hazards & cables:
Bricheno, L., Yeo, I., Clare, M., Hunt, J., Griffiths, A., Carter, L., Talling, P.J., Baker, M., Wilson, S., West, M. and Panuve, S., 2024. The diversity, frequency and severity of natural hazard impacts on subsea telecommunications networks. Earth-Science Reviews, p.104972.
Clare, M.A., Yeo, I.A., Watson, S., Wysoczanski, R., Seabrook, S., Mackay, K., Hunt, J.E., Lane, E., Talling, P.J., Pope, E. and Cronin, S., 2023. Fast and destructive density currents created by ocean-entering volcanic eruptions. Science, 381(6662), pp.1085-1092.
Clare, M.A., Yeo, I.A., Bricheno, L., Aksenov, Y., Brown, J., Haigh, I.D., Wahl, T., Hunt, J., Sams, C., Chaytor, J. and Bett, B.J., 2023. Climate change hotspots and implications for the global subsea telecommunications network. Earth-Science Reviews, 237, p.104296.
Pope, E.L., Talling, P.J., Carter, L., Clare, M.A. and Hunt, J.E., 2017. Damaging sediment density flows triggered by tropical cyclones. Earth and Planetary Science Letters, 458, pp.161-169.
Talling, P.J., Baker, M.L., Pope, E.L., Ruffell, S.C., Jacinto, R.S., Heijnen, M.S., Hage, S., Simmons, S.M., Hasenhündl, M., Heerema, C.J. and McGhee, C., 2022. Longest sediment flows yet measured show how major rivers connect efficiently to deep sea. Nature communications, 13(1), p.4193.
Using cables as sensors:
Clare, M.A., Lintern, G., Pope, E., Baker, M., Ruffell, S., Zulkifli, M.Z., Simmons, S., Urlaub, M., Belal, M. and Talling, P.J., 2024. Seismic and Acoustic Monitoring of Submarine Landslides: Ongoing Challenges, Recent Successes, and Future Opportunities. Noisy Oceans: Monitoring Seismic and Acoustic Signals in the Marine Environment, pp.59-82.
Hartog, A.H., Belal, M. and Clare, M.A., 2018. Advances in distributed fiber-optic sensing for monitoring marine infrastructure, measuring the deep ocean, and quantifying the risks posed by seafloor hazards. Marine Technology Society Journal, 52(5), pp.58-73.
Spingys, C.P., Naveira Garabato, A.C. and Belal, M., 2024. Distributed optical fibre sensing for high space‐time resolution ocean velocity observations: A case study From a macrotidal channel. Earth and Space Science, 11(5), p.e2023EA003315.
Spingys, C.P., Garabato, A.C.N. and Belal, M., 2024. Optical fibre sensing of turbulent-frequency motions in the oceanic environment. Scientific Reports, 14(1), p.20276.
Environmental impacts of subsea cables:
Clare, M.A., Lichtschlag, A., Paradis, S. and Barlow, N.L.M., 2023. Assessing the impact of the global subsea telecommunications network on sedimentary organic carbon stocks. Nature Communications, 14(1), p.2080.
Other co-authored publications with the International Cable Protection Committee that provide updates on environmental considerations: https://www.iscpc.org/publications/submarine-cable-protection-and-the-environment/
White Papers to which NOC scientists have contributed for the subsea cable industry:
ICPC White Paper: Fish Aggregation Devices, Their Impact on Submarine Cables, and Recommended MitigationICPC White Paper: Volcanic Hazards for Subsea Cables:
ICPC White Paper: Climate Change Hotspots and the Global Submarine Telecommunications Network
Co-authored Industry White Paper: Turbidity current hazards for subsea cables https://eartharxiv.org/repository/view/2405/?trk=public_post_comment-text
White Papers soon to be published will include: i) Enhancing resilience of subsea telecommunications for small islands to natural hazards; and ii) First environmental assessment of the impacts of subsea cable decommissioning.