Archive · 21 Aug 2026
Australia Investigates Undersea Cable Faults Threatening Internet Security
Australia gets most of its international internet through cables on the ocean floor.
Two of these cables recently developed problems near Perth.
The cables connect Australia with cities including Sydney, Jakarta and Singapore.
The damage may have been caused by an accident, such as an anchor or fishing net, but nobody knows for sure yet.
Some people are also worried that cables could be damaged deliberately.
Engineers are testing lasers that can detect movement and vibrations near cables.
These systems might show which ship or activity caused a problem.
This could help make Australia’s internet connections safer and more reliable.
Two Indigo submarine cable systems developed faults over the weekend, according to SubCo chief executive Bevan Slattery.
The Indigo West and Indigo Central cables connect Perth with Sydney, Jakarta and Singapore.
Undersea cables carry more than 95% of Australia’s international internet traffic.
The faults occurred inside the Perth Submarine Cable Protection Zone, but their exact cause remains unknown.
Researchers say laser-based distributed acoustic sensing could monitor cable activity and identify damaging vessels more quickly.
- Who
- SubCo chief executive Bevan Slattery announced the faults; researchers are studying monitoring technology.
- What
- The Indigo West and Indigo Central submarine cables developed shunt faults, and calls were made for an urgent investigation.
- When
- The faults developed over the weekend and were announced earlier in the week.
- Where
- The damage occurred inside the Perth Submarine Cable Protection Zone, on cables linking Perth with Sydney, Jakarta and Singapore.
- Why
- The faults matter because Australia relies on a limited number of undersea cables for more than 95% of its international internet traffic; the cause has not yet been established.
Accidental Damage
Possible Deliberate Damage
Likely cause remains unresolved
Accidental Damage
Most subsea cable faults are accidental, with ship anchors and fishing nets among common causes.
Possible Deliberate Damage
Growing concerns exist about deliberate damage, but the articles do not establish that the Perth faults were intentional.
- Damaged systems
- Indigo West and Indigo Central
- Connections
- Perth, Sydney, Jakarta and Singapore
- International cables
- There are 22 international submarine cables connected to Australia or being built.
- Traffic carried
- Undersea cables carry more than 95% of Australia’s international internet traffic.
- Fault type
- The faults were described as shunt faults involving damage to the electrical part of a subsea cable.
- Protection zone
- The Perth Submarine Cable Protection Zone extends more than 100 kilometres offshore.
- Potential monitoring technology
- Distributed acoustic sensing uses lasers to detect vibrations and activity near fibre-optic cables.