Tel Aviv Researchers Deploy Optical Fiber to Detect Tiny Earthquakes Under Sea of Galilee
A 14-kilometer optical fiber cable was recently installed on the bottom of the Sea of Galilee (Lake Kinneret) to study the active fault system beneath the lake and detect very small earthquakes undetectable by conventional methods. The project is led by a team from Tel Aviv University, including Prof. Ariel Lalloush from the Geophysics Department and Dr. Shaked Stein from the Israel Oceanographic and Limnological Research Institute. The Sea of Galilee lies along the Dead Sea Transform fault system, part of the complex Syrian-African Rift, which has historically caused damaging earthquakes in the region. However, many active faults are submerged, making monitoring difficult with standard seismic stations spaced kilometers apart.
The new technology uses seismic sensing through optical fibers, turning ordinary fiber optic cables into dense arrays of seismic sensors with meter-scale resolution. This allows for a much more detailed seismic picture than existing monitoring networks. The fiber was laid in cooperation with the Israel Oceanographic and Limnological Research Institute along a route crossing known faults and areas monitored for water currents and temperature, enabling simultaneous geological and environmental observations.
Deploying the fiber posed challenges due to GPS signal disruptions during installation, which the researchers overcame by tracking a GPS-equipped boat over the lake and correlating its position with signals detected by the fiber itself to precisely map the cable's path on the lakebed.
The researchers aim to characterize small earthquakes, locate active faults beneath the lake, assess seismic risks, and explore whether this data can improve early warning systems for nearby communities. Additionally, the fiber's sensitivity to water flow and temperature changes near the lakebed allows study of daily and seasonal cycles affecting the lake's thermocline, contributing to environmental research and climate change impact monitoring.
Prof. Lalloush emphasized that this technology reveals previously invisible seismic activity and environmental processes, opening new research opportunities on one of Israel's vital natural resources. Dr. Stein noted that the Sea of Galilee has been monitored for over 50 years, and this high-resolution data layer significantly enhances understanding of current processes at the lakebed and its surroundings.
