Fiber Optic Cables Detect Earthquakes

TÜBİTAK Informatics and Information Security Research Center (BİLGEM) has been detecting earthquake-induced seismic movements for approximately ten months with the underground fiber cable embedded in Kocaeli Gebze campus. With Fiber Optic Based Acoustic Sensor (FOTAS) system, the prototype of which was developed in cooperation with SAMM Technology earthquakes in our country has begun to be recorded with fiber cables used for communication purposes. With FOTAS, it has been observed that earthquakes in the Marmara region are easily perceived, and earthquakes in remote areas can also be detected according to their magnitude, and especially the M6.8 Sivrice (Elazığ) earthquake that occurred on 24 January  2020 was easily detected even though it was approximately 900 kms away from the campus.

The light energy transmitted through the fiber optic cable is sensitively affected by all kinds of physical activities along the route of the line. When this effect is analyzed with appropriate optical and electronic hardware and signal processing methods, it becomes feasible to use the entire cable as hundreds or even thousands of virtual acoustic microphones. For this reason, the use of fiber optic cables in areas such as border and critical facilities security is rapidly spreading. In addition to security-oriented use, researches on the operability of the fiber optic communication infrastructure for the investigation of seismic movements have accelerated in many countries. Considering the kilometers long fiber optic cable infrastructure, it seems possible to use the existing communication infrastructure as thousands of seismic sensors. As a result of the ongoing research and development studies initiated by TÃœBÄ°TAK BÄ°LGEM, it has been confirmed that even earthquakes hundreds of kilometers away can be detected with a fiber optic cable of a few kilometers length. It was observed that the epicenter distances of earthquakes in the Marmara region and its vicinity were also calculated correctly.

The BİLGEM project team came together with the scientists at both Boğaziçi University Kandilli Observatory and Earthquake Research Institute of Istanbul Technical University, and stated that they have begun to evaluate the opportunities of using this technology for public interest and earthquake research.

It is stated that for the expected earthquake in the Marmara region, the analysis opportunities of seismic movements can be investigated using the existing communication infrastructure, and studies are planned to effectively evaluate this technology for our an earthquake-prone country.

For information bilgem@tubitak.gov.tr