Nuclear surveillance systems suggest landslides blocking the internet in West Africa

A light blue signal captured by the global international nuclear surveillance system suggests that underwater landslides for weeks in March 2024 could have destroyed communication cables and destroyed internet traffic in West Africa.

Using data collected by hydrophones installed by the Comprehensive Nuclear Testvan Convention Agency (CTBTO) international surveillance system, the researchers determined possible landslide locations and positioned them along the steep slopes of the ships on the courts’ vessels.

According to a colleague, Vibeb Vijay Ingale, a Oceanography Institute in San Diego, California, and colleague Vibeb Vijay Ingale, the proposed landslide corresponds to the timing and location of four broken cables in the canyon.

“This detection off the coast of Ivory Coast is particularly exciting as it demonstrates the potential to use existing water joint data to monitor submarine landslides more effectively,” Gale said. “This suggests that such events are simply unaware of because of a lack of surveillance infrastructure or because we were not actively looking for them in our hydroacoustic data.”

On March 14, 2024, four communication cables broke in an offshore canyon about 107km off Abidjan city on the Ivory Coast. The extent of service disruption has made it important to determine the cause of the break, Ingale said.

Researchers decided to look for “acoustic detection of the signals behind the incident” as these low-frequency waves can talk about a variety of sources, including earthquakes, volcanic eruptions, sea submarines, and the biological activities of seawater columns.

One of the closest sources of waterway data came from the hydrophone, which was deployed near Ascension Island, as part of the Nuclear Test Ban Treaty Network. “When we looked at the hydroacoustic data recorded between March 6th and March 22nd, 2024, the low-frequency signal from March 12 caught our attention,” Ingale said.

The signal was relatively short (less than 1.5 minutes) and was not detected before or after the cable break. The signal was detected only by hydrophones, not by land stations. And when researchers looked at seismic data in the area, they found no events with arrival times that matched their low-frequency signals.

Ingale and colleagues concluded that the signal likely came from a submarine landslide, making this the first reported example of using a hydrophone to detect such landslides.

“This was the first example of detecting submarine landslides with hydrophones that are not related to earthquakes or eruptions, so there was no precedent as to how signals should appear,” Ingale said. “We had to carefully scan available data with unusual patterns that didn’t resemble known structural or volcanic signals. The difficulty was exacerbated by the fact that hydrophone data was noisy due to ocean sounds like marine life, vessel traffic, and other anthropogenic interactions.”

Once geophysicists and acousticians confirmed the presence of “true” landslide signals, they used the signal data to calculate where the signal was originated and placed them in locations that coincide with cable breaks and steep slopes of the underwater canyon.

Ingale says that if the hydrophone can reliably detect signals from submarine landslides, it can be used as part of the cable operator’s early warning system, identifying threats and assisting in preparing for confusion.

“In addition, insights from light blue monitoring could lead to better engineering standards, such as deeper burial of cables in areas where sediment is prone to generation, and re-routing around historically unstable slopes,” he proposed. “If cable breakage occurs, analyzing light blue-style data can help you determine if landslides are the cause, help with forensic analysis, insurance claims, and understand the broader risks to subsea infrastructure.”