Textile sensing technology can provide early warnings for volcanic eruptions

The Reykjanes Peninsula, located on the southwest tip of Iceland, is one of the most populous regions in the country and one of the most volcanic regions. In 2024, Sensing Technology, developed by Caltech, was deployed locally to study the movement of underground magma and eruptions into lava on the surface.

Using data from a technology called distributed acoustic sensing (DAS), researchers have developed a method to provide warnings up to 30 minutes before a lava eruption. This study shows that DAS could be a useful tool for studying volcanic activity and providing early warnings to the public.

This study was conducted in the lab of Zhongwen Zhan (Doctor ’13), professor of geophysics, leadership chair for Clarence R. Allen and director of the Caltech Institute of Seismic Sciences. The paper describing this study was published in Journal Science on April 24th.

Since November 2023, the Reykjanes Peninsula has experienced eight lava eruptions, some of which have grown to threaten the town. Although Iceland itself is relatively volcanic and active, researchers theorize that this particular field could enter an increasing period of activity.

To study this, Zhan and his team developed a collaboration between Icelandic scientists and telecommunications company Ljósleidarinn, deploying DAS sensors on the peninsula for a year with the aim of better characterizing volcanic activity and developing an early excavation system for eruptions.

“The development was very fast,” says Jiaxuan Li, the first author of the study and former postdoctoral scholar at Caltech, now an assistant professor at the University of Houston. “Within 10 days of the substantial magma invasion event that took place on November 10, 2023, we were able to set up the system on 100 kilometers of textile cables. About a month later, we recorded our first eruption with our system. This was a major international cooperation with actual impact.”

DAS works by pointing it towards a laser-free underground fiber optic cable (such as providing the internet). When vibrations pass through the cable, whether they are earthquakes or from the rumble of traffic, laser light experiences what is called phase change. When measuring the phase change of this laser light, researchers provide information about the passing waves and create a 100-kilometer cable, equivalent to the lines of thousands of traditional seismic sensors.

Volcanic activity also causes underground deformation. When magma pushes up from a shallow basement, the ground will stretch and compress. There, sufficient pressure is applied to erupt onto the surface through cracks called embankments. DAS can accurately measure underground movements on the order of millimeters in real time, with much higher resolution than GPS or satellite imaging.

Over the years of research, DAS collected data on underground volcanic activity and monitored how the Earth grew in real time as magma moved around. From this data, the team developed a preliminary early warning system that gave the public 30 minutes to several hours of advance notice prior to the eruption, depending on the nature of the magma invasion.

The study’s co-author, Seismicologist Vala Frelifsdutil, from the University of Reykjavik, worked in Iceland to devise an early warning method for eruptions. In particular, the active eruption site near the town of Glindavik poses a threat to the town’s thousands of residents. Once the Caltech team set up the DAS sensor, Hjörleifsdóttir worked with them to identify a signal of data indicating that an eruption was coming.

“One day, in August 2024, we attended a group meeting in California and my phone started to turn off with early warning alerts,” Li says. “Twenty-six minutes later, Vara emailed us that the eruption had actually happened and that they sent out an evacuation warning.”

“This is Iceland’s most active volcanic system,” says Zhan. “In addition to the need to provide advance warnings before an eruption, the project is scientifically interesting because we saw more magmatic invasion events than we originally thought.

“There’s so much to do and every volcano is different, but DAS offers a new ability to see things that haven’t happened before. Our project is also a great example of the power of international collaboration.”