Earthquake early warning (EEW) systems provide warning time in the seconds to tens of seconds before potentially damaging ground motions are felt. Seismic sensors should be installed as close to the expected earthquake source for the best warning times. However, while the most dangerous earthquakes occur underwater, most seismological stations are located on land, and these earthquakes may go undetected for several seconds.
Dr. Itzhak Lior of the Institute of Earth Sciences at the Hebrew University of Jerusalem published a new study in Nature’s Scientific Reports journal demonstrating that optical communication fibers can provide early warning for devastating earthquakes.
Every year, thousands of earthquakes occur around the world, most of which are minor and cause no damage. On the other hand, strong earthquakes can cause massive damage and casualties. While current earthquake monitoring technology can provide early warning for earthquakes on land, earthquakes on the seabed are usually detected tens of seconds after they begin. Offshore earthquakes are the most powerful and destructive on Earth, and their late detection significantly reduces warning times and our ability to prepare for them.
Dr. Lior. said, “Earthquakes that occur under the seabed or in areas without sensors can delay detection by existing technologies, which hinders preparation. An innovative method for monitoring earthquakes using optical fibers, including those deployed worldwide for Internet communication, has recently gained momentum. In this study, we showed that optical fibers can be used instead of the traditional sensors to provide early warning, especially for earthquakes that occur at sea.”
The study examined earthquakes recorded by several optical fibers deployed on the seabed off Greece, France, and Chile coasts. It determined the intensity and damage potential of the earthquakes before they were felt on land.
The findings show that using existing fiber infrastructure can simplify and accelerate the setup and operation of earthquake warning systems and improve warning times.
Dr. Lior continues, “Optic fibers, including fibers from commercial telecommunications companies, can determine the intensity of earthquakes and their damage potential very quickly, adding critical seconds of warning for destructive earthquakes. Using communication fibers from commercial companies is a significant advantage for areas at risk of earthquakes such as Chile, Japan, the west coast of North America, and Israel.”