Indonesian earthquake caused anomalies on several submarine cables

What Happened

On May 29, 2026, at 11:54 local time, an earthquake of magnitude 4.5 occurred 108 km NNW from Bukittinggi, Indonesia.

Cables in the Zone

Several key submarine cables are within a radius of 500 km from the event:

• India Asia Xpress (IAX) — distance to the earthquake center is 5791.0 km, owned by China Mobile and Reliance Jio Infocomm. In the zone, it is 283.1 km from Morib, Malaysia.
• Asia Submarine-cable Express (ASE)/Cahaya Malaysia — distance to the earthquake center is 8148.0 km, owned by NTT and PLDT. In the zone, it is 445.8 km from Changi South, Singapore.
• Dumai-Melaka Cable System (DMCS) — distance to the earthquake center is 159.0 km, owned by Telekom Malaysia and Telkom Indonesia.

What Our Measurements Show

Significant anomalies were detected on some cables:

• IAX: baseline RTT latency was 97.8 ms, which increased to 209.8 ms after the earthquake (enhanced sigma estimate +4.5σ).
• ASE/Cahaya Malaysia: baseline RTT latency was 93.6 ms, which increased to 196.5 ms after the earthquake (enhanced sigma estimate +3.8σ).

Context and Risks

These changes may impact global internet traffic, particularly for regions in Southeast Asia and India. The earthquake may cause traffic rerouting through other routes, which could further strain remaining cables.

Ongoing Monitoring

We will continue to monitor all cables in the zone and related routes to determine further consequences for the global network.