Undersea Internet Cables

Digital A significant portion of today’s global internet connectivity is provided by fiber optic optical cables laid beneath sea. Currently, more than 1.4 million kilometers of ocean submarine cables exist, and these cables carry 99% of all internet data traffic. From this perspective, submarine internet cables serve as the foundational infrastructure of global civil and military communications, and understanding their structure is essential to importance supply.

Submarine Internet Cables Map, Submarine Cable Map

Principle of Operation of Submarine Cables

Submarine cables transmit data using fiber optic technology. Data sent as light from one end travels through thin glass fibers and is received at the other end by a detector. The main components of submarine cables are:

• Fiber optic core cable: Transmits data at the speed of light.
• Insulation and waterproof coatings: Protect the cable from external environmental factors.
• Reinforced armor and steel wires: Provide resistance against wear and breakage, especially in shallow waters.
• Amplifiers (Repeaters): Placed at intervals of approximately 50 to 100 kilometers to prevent signal degradation over long distances.

Technical characteristics:

• Data Transfer Speed: Modern fiber optic submarine cables can transmit up to 100 Tbps.
• Latency: Delays between continental connections can be kept below 60 ms.
• Cable Lifespan: Designed to operate for an average of 25 years.

Structure of Submarine Cables, Navegalo

History of Submarine Cables

The history of submarine telecommunications cables dates back to 1858 with the first transatlantic telegraph line. Fiber optic technology has been in use since the 1980s.

Important events:

• 1866: The first successful transatlantic telegraph cable was laid.
• 1988: The first fiber optic transoceanic cable, TAT-8, was commissioned.
• 2011 Japan Earthquake: Many submarine cables were damaged due to the tsunami, severely affecting Japan’s global internet access.
• 2022 Fishing Vessel Accident: A ship’s anchor severed submarine cables off the coast of Taiwan, causing major internet outages worldwide.

Sharks are biting Google’s submarine cables, Hürriyet

Türkiye and the Submarine Cable Network

Türkiye occupies a strategic position between Europe, Asia and East, making it a critical transit hub.

Major submarine cables connected to Türkiye include:

• KAFOS: A system starting in Istanbul that connects Türkiye to Romania and Bulgaria via the Black Sea.
• MedNautilus Submarine System: The largest Mediterranean submarine cable network, starting in Istanbul and connecting Türkiye to Italy, Greece, Israel and Cyprus.
• SeaMeWe-5: This extensive cable system links Asia, Africa and Europe, and connects to Türkiye via a cable landing in Marmaris, Muğla.
• Turcyos-1: Provides connectivity between Türkiye and Cyprus, starting in Bozyazı, Mersin and terminating in Girne, Cyprus.
• Turcyos-2: Provides connectivity between Türkiye and Cyprus, starting in Samandağ, Hatay and terminating in İskele, Cyprus.

Türkiye Submarine Internet Cables Map, Submarine Cable Map

Significant Events in Türkiye

• 2015 Istanbul-Bodrum Submarine Cable Outage: Damage to the MedNautilus cable caused major delays in Türkiye’s international internet traffic.
• 2020 İzmir Earthquake: Physical damage occurred to some cables in the Aegean Sea, resulting in localized outages.

Security Risks and Geopolitical Tensions

Submarine cables have become central to geopolitical conflicts place. For example, the USA–China rivalry has turned this critical infrastructure into a strategic target.

Threats:

• Cyberattacks: Data traffic over cables can be intercepted or rerouted.
• Physical disruptions: Cables may be damaged by fishing activities, ship anchors or natural disasters.
• Military interventions: Some countries may target the submarine cable infrastructure of rival nations.

Maintenance of SeaMeWe-5 cables, Dailysun

Future Expectations

Planned developments:

• Cables reaching 1 Pbps speeds: Ultra-high bandwidth investments planned for after 2025.
• Quantum-secure data transmission: Integration of quantum technologies for encryption and data security.
• Autonomous cable repair systems: Robots capable of repairing damaged cables without human intervention.