Aiming to monitor and mitigate risks to heritage sites from future seismic events, a team of Italian researchers have for the past few months begun running a structural health monitoring system on the Tower of David in Jerusalem.
The system, installed in November 2013, consists of eight high-sensitivity accelerometers that record the dynamic behavior of the building, which is subject to ambient vibrations as well as possible seismic events.
As the tallest structure in Jerusalem’s Old City, researchers felt that the Tower of David was the ideal structure to place the monitoring systems.
The project is running under the leadership of Prof. Claudio Modena, head of the engineering faculty at the University of Padova, who previously led a European Union-sponsored project, called the New Integrated Knowledge Based Approaches to the Protection of Cultural Heritage from Earthquake-Induced Risk (NIKER) project.
“Among the different historical constructions here in Jerusalem, the tower is particularly sensitive to possible effects of earthquake,” Modena told The Jerusalem Post on Monday.
Modena and his colleagues, who were in Israel for the past two days taking part in a workshop on “Seismic Risk Preparedness and Mitigation of Archaeological and Historical Sites,” intend to keep the monitoring system functioning at the Tower of David for at least one year, he said.
The one-year time frame is necessary because the tower is sensitive to variations in temperature and humidity, Modena explained.
Eilat Leiber, director of the Tower of David, said that she and her staff are proud that Modena and his team chose their site for the monitor system.
“We [have been] maintaining the ancient citadel of Jerusalem for 24 years,” she said. “Part of our everyday job is to preserve the citadel.”
In addition to participating in University of Padova’s seismic monitoring program, Leiber said that she has hired a panel of archeological experts to assess the building’s condition.
“We are aware of the risk because we can see the seismic results here in the walls of the citadel,” she said. “We are very happy with the collaboration with the University of Padova because they are pioneers in the research about archeological sites and about seismic risks.”
Usage of the new equipment will allow the researchers to see “what’s going on every day, every hour, every second” in an archeological site that Leiber defines as “a symbol of the city,” she said.
Selecting a historical site that is “important to so many cultures” was critical, according to Prof. Avi Shapira, chairman of Israel’s National Steering Committee for Earthquake Preparedness.
“Earthquakes did occur in this region in the past and they surely will be as strong as they were,” he said. “They will repeat themselves.”
Acknowledging that the country can never be fully prepared for earthquakes, as this is a huge task requiring billions of dollars, Shapira said that Israel is much more prepared than it was a century ago and is in a good place in comparison to other nations around the world.
Private citizens, however, must take it upon themselves to strengthen their homes properly, he explained.
“Earthquakes cannot be forecasted and we cannot predict when they will occur,” Shapira said.