2022-01-19 05:08:19 GMT2022-01-19 13:08:19(Beijing Time) Sina English


The Tonga volcanic eruption has revealed the vulnerabilities in our global telecommunication system

In the wake of a violent volcanic eruption in Tonga, much of the communication with residents on the islands remains at a standstill. In our modern, highly-connected world, more than 95 per cent of global data transfer occurs along fibre-optic cables that criss-cross through the world’s oceans.

在南太平洋岛国汤加发生猛烈的火山喷发后,岛上居民的大部分通信处于停滞状态。在我们这个高度互联的现代世界中,超过 95% 的全球数据传输是通过穿越海底的纵横交错的光缆进行的。

Breakage or interruption to this critical infrastructure can have catastrophic local, regional and even global consequences. This is exactly what has happened in Tonga following Saturday’s volcano-tsunami disaster. But this isn’t the first time a natural disaster has cut off critical submarine cables, and it won’t be the last.


What exactly has happened in Tonga?


Tonga was only connected to the global submarine telecommunication network in the last decade. Its islands have been heavily reliant on this system as it is more stable than other technologies such as satellite and fixed infrastructure.


The situation in Tonga right now is still fluid, and certain details have yet to be confirmed – but it seems one or more volcanic processes (such as the tsunami, submarine landslide or other underwater currents) have snapped the 872km long fibre-optic cable connecting Tonga to the rest of the world. The cable system was not switched off or disconnected by the authorities.


This has had a massive impact. Tongans living in Australia and New Zealand can’t contact their loved ones to check on them. It has also made it difficult for Tongan government officials and emergency services to communicate with each other, and for local communities to determine aid and recovery needs.


Telecommunications are down, as are regular internet functions – and outages keep disrupting online services, making things worse. Tonga is particularly vulnerable to this type of disruption as there is only one cable connecting the capital Nuku'alofa to Fiji, which is more than 800km away. No inter-island cables exist.

海底网络电缆和电话信号中断,互联网信号亦如此,这严重影响了其在线服务,使情况变得更糟。汤加特别容易受到这类干扰的影响,因为汤加首都努库阿洛法和800 多公里外的斐济只有一条电缆连接,而两岛间没有其他电缆连接。

Risks to submarine cables elsewhere


Cables are laid in the shortest (that means cheapest) distance between two points on the Earth’s surface. They also have to be laid along particular geographic locations that allow easy placement, which is why many cables are clustered in choke points.


Some good examples of choke points include the Hawaiian islands, the Suez Canal, Guam and the Sunda Strait in Indonesia. Inconveniently, these are also locations where major natural hazards tend to occur.


Once damaged it can take days to weeks (or even longer) to repair broken cables, depending on the cable’s depth and how easily accessible it is. At times of crisis, such outages make it much harder for governments, emergency services and charities to engage in recovery efforts.


Many of these undersea cables pass close to or directly over active volcanoes, regions impacted by tropical cyclones and/or active earthquake zones.


In many ways, Australia and New Zealand are also very vulnerable (as is the rest of the world). Australia is connected to the global cable network by a very small number of connection points, from just Sydney and Perth.


In regards to Sydney and the eastern seaboard of Australia, we know large underwater landslides have occurred off the coast of Sydney in the past. Future events could damage the critical portion of the network which links to us.


How do we manage risk going forward?


Given the vulnerability of the network, the first step to mitigating risk is to undertake research to quantify and evaluate the actual risk to submarine cables in particular places on the ocean floors and to different types of natural hazards. For example, tropical cyclones (hurricanes/typhoons) occur regularly, but other disaster such as earthquakes and volcanic eruptions happen less often.


Currently, there is little publicly available data on the risk to the global submarine cable network. Once we know which cables are vulnerable, and to what sorts of hazards, we can then develop plans to reduce risk.


At the same time, governments and the telecommunication companies should find ways to diversify the way we communicate, such as by using more satellite-based systems and other technologies.


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