Around 600 undersea cables carry electricity and information across vast oceans and seas. The majority are data cables, which are responsible for almost all the internet traffic and perform a vital function in our everyday lives in this era of technology.

Some 870,000 miles of cable connect individuals across the globe, often coming ashore at obscure locations. This interactive map, produced by TeleGeography, showcases the incredible extent of modern technology infrastructure. Some 18 submarine cables stretch across the Atlantic Ocean between the North American continent and North Europe, including the 7,581-mile EXA North and South cable, which connects Southport, Dublin, Coleraine in Northern Ireland, Halifax in Canada and Lynn in Massachusetts.

The 2Africa cable, meanwhile, stretches a staggering 28,000 miles around the entire African continent, connecting the UK with Portugal, the Canary Islands, Angola, Madagascar, India, the UAE, Bahrain, all the way through the Suez Canal to Europe, including Italy, France and Spain.

The map also puts into perspective just how fragile the interconnected world is and how concerning fears of sabotage are.

Shortly after midday local time on Christmas Day 2024, workers at the Finnish electricity company Fingrid noticed the main undersea electricity cable linking Finland with Estonia had been damaged - Estlink 2 - significantly reducing the latter’s power supply. As of December, the failure was expected to last seven months and cost tens of millions of euros.

The damage to the 105-mile-long cable marked the latest in a series of incidents in which Baltic underwater cables have been either damaged or severed completely since Russia's full-scale invasion of Ukraine.

What’s more, a new deep-sea device created by China has sparked fears it could plunge the world into darkness as it is deemed capable of severing critical undersea communication and power cables 13,000 feet below the surface.

Developed by the China Ship Scientific Research Centre (CSSRC) and its State Key Laboratory of Deep-sea Manned Vehicles, this compact device's 150mm diamond-coated grinding wheel spins at 1,600 rpm with incredible precision, generating enough force to shatter steel cables while minimising sediment disturbance.

If China were to deploy such a device near critical chokepoints - for example, around Guam, a strategic hub for US military operations - it could result in entire regions being cut off from the internet, the collapse of banking systems and the ruin of vital communications.

“Deep-diving submarines can sever cables at depths which make repairs extremely difficult,” explained Dr Sidharth Kaushal, senior research fellow in sea power at the Royal United Services Institute (Rusi) to the BBC.

In a world that now relies heavily on the internet and electricity, the consequences could be disastrous if China started using its new deep-sea cable cutter against its enemies.