Avalanches hitting the road pose a significant risk. Fiber optic sensing is a new technology that can be utilized to monitor and detect avalanches over roads and vehicles in the area. Simultaneous monitoring of traffic and avalanches is invaluable for search and rescue operations, and by closing the road in time, one can prevent further traffic from entering the danger zone.

The technology makes it possible to use telecommunication cables along the road as sensors with high resolution in both time and space, and it can cover large areas. The core of the technology (Distributed Acoustic Sensing) is an interrogator that sends laser pulses through the fiber and analyzes the backscatter. The project used an interrogator from ASN with a range of up to 150 km. With this technology, many avalanche zones can be covered by one system.

During the winter of 2022/2023, a pilot system was installed in Holmbuktura (1.4 km) in Troms for testing. A supplier group consisting of NORSAR, Norconsult, and Alcatel Submarine Networks developed and installed the system. NORSAR was responsible for developing the detectionsolution, which monitors in real time and sends alerts in the event of avalanches. The testing has been successful, with good precision in determining whether the avalanche has hit the road and with few false alarms.

The work has been continued after the project, including monitoring during the 2024 season.

See our solution for detecting snow avalanches using fiber technology: