An Earthquake early-warning system for a safer Europe
Even 10 seconds can make a difference. When Japan was hit by the earthquake in 2011, early-warning systems were in place, and within seconds even the high-speed "bullet" trains stopped.
About half of Europe is also a high-risk earthquake area, especially Mediterranean countries like Greece, Italy, and also other regions around the Black Sea.
Unlike for the weather, there are currently no reliable methods to predict earthquakes. However, earthquakes do send a warning signal. "When an earthquake occurs, the first wave--ground vibration that reaches you is not dangerous, but it contains vital information about the event," says Paolo Gasparini of the Physics department of the University of Naples and AMRA Scarl, a research organisation of the University. This initial ground wave travels very fast and arrives tens of seconds to minutes earlier than the main, destructive wave. The intensity of this initial ground vibration will indicate the destructive power of the earthquake.
But what is more important is that these seconds and minutes allow people to protect themselves or reach safety. The activation of early-warning systems can also mitigate the impact of an earthquake by shutting down railways, gas pipes, and even nuclear power plants, explains Gasparini.
To start the development of an early-warning system in Europe, the European Commission funded, with €3.6 million, a 30-month research programme called SAFER (Seismic early warning For Europe). Started in July 2006 and coordinated by the GeoForschungs Zentrum (GFZ) in Potsdam, Germany, researchers from 19 European institutions were part of the consortium. Also participating in the project were researchers from four institutions in Japan, the United States, Taiwan and Egypt.
"The main aim of the project was to develop a novel, early-warning capability for Europe utilising the initial, information-carrying wave produced by earthquakes," says Gasparini, who was a member of the SAFER Steering Committee.
Demonstrator projects were set up in Istanbul, Bucharest, Naples, Athens and Cairo. In Bucharest a warning system is already operational in the city, while in Istanbul such a system is implemented for the bridge spanning the Bosphorus.
The prototype warning systems developed by SAFER consist of networks of seismic stations placed near fault zones. Each seismic station is equipped with seismometers and accelerometers that detect ground vibrations. The latter, low-cost instrument is comparable to the accelerometer that triggers the inflation of the airbags in your car during a collision. These stations are linked via wireless systems to a processing center where the data is analysed, leading to a real-time assessment of the strength of the earthquake. If the earthquake presents a danger, warnings are issued and actions to stop trains and close down industrial installations are taken automatically. For example, Naples is protected by a prototype system consisting of 30 seismic stations placed around the fault zone under the Appenines, 80 km east of the city, reports Gasparini.
The processing center, at the Engineering Faculty of the University of Naples, will have ten seconds to assess data before the destructive wave arrives. "The lead time is very short, and you have to rely on automatic actions and on preparedness," says Gasparini. "People have to know what to do because they have only seconds to react."
The development of response strategies to earthquakes, which was not part of the SAFER project, is part of a current project called REAKT (Strategies and tools for Real-time EArthquake risK reducTion), that will deal with the people' responses. More specifically, REAKT explores how to use the information coming from earthquake forecasts, early warnings and real-time assessments of the vulnerability of built structures. All this information will be combined in a probability framework that will be used by emergency managers to make decisions in real time. This system for risk reduction will be applied to vulnerable infrastructures, including trains, industries, hospitals, bridges, and schools.
REAKT will also study possibilities for forecasting earthquakes. "For example, the detection of moderate seismic activity or ground deformation can indicate an increase in the probability of a pending earthquake," says Gasparini.
An important result of SAFER is that it has primed the European research community for just this type of research. "We have developed a real network of experts, young people in many European countries, that have worked together for five years and together have gained valuable experience," comments Gasparini.