Two crucial undersea internet cables, the Indigo West and Indigo Central systems, have sustained damage within a designated protection zone off the coast of Perth, Australia. This alarming development has prompted calls for an urgent investigation by federal police, as these cables are fundamental to Australia's international internet connectivity.
Submarine cables are the backbone of global communication, transmitting over 95% of Australia's international internet traffic. While satellites serve remote areas, they lack the immense data capacity of fiber-optic cables, each capable of carrying more than 20 terabits per second.
Understanding the Damage
The faults, described as "shunt faults" by SubCo chief executive Bevan Slattery, occur when the electrical component of a subsea cable is compromised, affecting its performance. These cables rely on electricity to power optical amplifiers that boost signals every 50 to 100 kilometers. The exact cause of the damage within the Perth Submarine Cable Protection Zone, which extends over 100 kilometers offshore, remains unknown.
While deliberate sabotage is a growing concern, most subsea cable faults are accidental, often caused by ship anchors or fishing nets dragging across the seabed. The vastness of the protected zone makes constant monitoring challenging.
Laser Technology for Enhanced Protection
Experts are exploring advanced technologies to safeguard this critical infrastructure. Distributed Acoustic Sensing (DAS) uses lasers to monitor vibrations along fiber-optic cables, detecting activities such as nearby ship movements or seabed disturbances. This technology sends light through the fiber and analyzes subtle changes in the returning light to pinpoint potential threats.
Slattery noted that if DAS had been installed on the damaged cables, the vessel responsible could have been identified almost instantly. The technology is already deployed on undamaged nearby cables, confirming no seabed activity around them.
Future of Cable Monitoring
Researchers are also investigating whether the same fiber can simultaneously carry internet data and perform monitoring functions, potentially allowing existing cables to act as real-time sensors. Additionally, optical microcomb technology is being developed to make these sensing systems smaller, more efficient, and more cost-effective. For Australia, which depends on a relatively small number of international undersea cables, such innovations could significantly enhance the resilience and security of its vital communication networks.