Earthquake: This is how early warning systems work
You can prevent worse
This is how early warning systems for earthquakes work
A seismograph records the vibration of an earthquake (archive image).
© Source: Ralf Hirschberger
Berlin/Trieste. Predicting an earthquake in concrete terms is not yet scientifically possible. However, there are complex early warning systems that can quickly detect tremors, as the Helmholtz Association’s Research Department Earth and Environment explains.
Regional systems are installed in the areas where earthquakes are expected. There, a seismic observation network records strong vibrations in the ground. Several types of seismic waves are produced during an earthquake, including a relatively low-vibration compressional wave (P-wave) and the destructive shear wave (S-wave). There are a few seconds between them close to the epicenter. “The further away you are, the more time there is for an alarm. If you are close to the epicenter, the S-wave has already arrived before it,” says Professor Stefano Parolai from the University of Trieste.
+++ All developments after the severe earthquakes in Turkey and Syria in the live blog +++
Software triggers an alarm and shuts down associated infrastructure
During this time, software platforms receive the real-time signals from the observation network, process them and send out an alarm. The linked infrastructure ensures that warnings are issued immediately, such as shutting down power and gas lines, stopping trains, closing bridges and halting dangerous industrial processes.
Another early warning system works with the following strategy: There, the seismic measurements are taken at the point that is to be protected – for example in a city or at an industrial plant. The measuring devices registered the P wave, could deduce from it how strong the S wave would be and accordingly immediately trigger measures, according to expert Parolai.
Warning for current quake not possible
With the current earthquake in Turkey and Syria, such an early warning would not have been possible regardless of the system used, explains Marco Bohnhoff from the German Research Center for Geosciences (GFZ) Potsdam. Because the densely populated region affected is in the immediate vicinity of the epicenter, there was no period for warnings.