July 2026 Ionian Sea earthquake disrupts submarine cables near Santa Doménica, Italy

What Happened

On July 24, 2026, at 01:55:57 UTC, an earthquake of magnitude 4.7 occurred 56 km northwest of Santa Doménica, Italy. The epicenter was located in the Ionian Sea, in an area where several key submarine cables connecting Europe with the Middle East and North Africa run. This event caused anomalies in the operation of some cables, which were detected by our monitoring system.

Cables in Zone

Within a radius of 500 km from the epicenter, there are eight submarine cables. Among them:

• MedNautilus Submarine System (7000 km, RFS 2001, Sparkle), passing through Catania, Italy (167.7 km from the epicenter).
• OTEGLOBE Kokkini-Bari (700 km, RFS 2004, OTEGLOBE), with a node in Bari, Italy (268.4 km).
• Adria-1 (440 km, RFS 1996, ALBtelecom, Hrvatski Telekom), with a node on Corfu, Greece (397.2 km).
• Piano Isole Minori (830 km, RFS 2024, Infratel Italia), through Aliqudia Porto, Italy (101.9 km).
• Ionian (320 km, RFS 2023, IslaLink), through Crotone, Italy (151.9 km).
• SeaMeWe-5 (20000 km, RFS 2016, BSCCL, China Mobile), passing through Catania, Italy (167.7 km).
• Italy-Malta (238 km, RFS 1994, GO plc, Sparkle), passing through Catania, Italy (167.7 km).
• IMEWE (12091 km, RFS 2010, Bharti Airtel, Ogero), also through Catania.

The most significant anomalies were recorded on the cables MedNautilus, OTEGLOBE Kokkini-Bari, and Adria-1.

What Our Measurements Show

The monitoring system has detected the following changes in signal delay (RTT):

• On the MedNautilus Submarine System RTT increased from 73.3 ms to 160.2 ms (delta +86.9 ms, 26.4σ from baseline).
• On the OTEGLOBE Kokkini-Bari RTT rose from 65.0 ms to 116.8 ms (delta +51.8 ms, 7.9σ).
• On the Adria-1 RTT increased from 33.4 ms to 116.0 ms (delta +82.7 ms, 2.6σ).

These anomalies indicate possible impact of an earthquake on submarine infrastructure, although physical cable damage has not yet been confirmed.

Context and Risks

The Ionian Sea region is a crucial node for submarine cables connecting Europe with other regions. Anomalies in cable performance may lead to increased data transmission delays and traffic rerouting. This can affect the quality of internet services, especially in countries of Southern Europe and Eastern Mediterranean.

Moreover, such events highlight the need for regular monitoring and timely response to risks associated with natural disasters.

Further Monitoring

We will continue to monitor the condition of cables in the earthquake zone, particularly MedNautilus, OTEGLOBE Kokkini-Bari and Adria-1. Special attention will be given to changes in RTT and possible physical damages. We will also analyze traffic redistribution and its impact on the global network.

Updates on the situation will be published as new data becomes available.