Thursday, March 11, 2010

Earthquake of up to 7 on Richter scale expected to hit Lebanon

Source: The Daily Star
BEIRUT: The head of the Order of Engineers and Architects said Thursday that an earthquake might hit Lebanon. “Studies have showed that an earthquake with a maximum 6.5 to 7 on the Richter scale is expected here,” Samir Doumit said during a news conference held by the National Council for Scientific Research (NCSR) on seismology and tectonics in Lebanon. However, he said, “buildings designed with minimum resistibility to earthquakes” will escape much of the destruction.

“Earthquakes are [a] natural occurrence we can’t prevent, but we can take adequate measures to lessen its damaging impact,” he said. On August 10, an article published in The Daily Star said that “a new underwater survey has revealed that Lebanon lies dangerously close to a fault that could soon generate a catastrophic tsunami.”

The article quoted a report by Discovery News channel which said that a fault lying just 6.5 kilometers off Lebanon’s coast caused a tsunami-generating earthquake in 551 AD. According to the survey, the fault moves approximately every 1,500 years, meaning a disaster of the same magnitude as the earthquake and tsunami that destroyed coastal cities on July 9, 551, could be due any time.

The Order of Engineers and Architects warned contractors and architects in Lebanon about the extent of the expected damage of “probable” earthquakes. Doumit said rumors have been spreading during the past few days about the possibility of an earthquake, but he stressed that “no one can specify the timing of the earthquake.”

The National Center for Geophysics, in collaboration with a French team of researchers, discovered a major fault connected with the Yammouneh fault, starting from the South of Marjayoun to the North at Qobeiyt, according to Dr. Ata Elias, a researcher at the National Center for Geophysics. “Studies showed that the fault is of 100-150 kilometers across the shore between Sidon and Tripoli at a depth of 1,300-1,500 meters,” said Elias.

Elias added that photos taken by a French submarine equipped with cutting-edge geophysical technologies showed cracks and fractures all along the fault, indicating its “activity.” “Our discovery of the Mt. Lebanon fault allows us to better estimate the risks of the probable earthquakes and tsunami waves,” Elias said, adding that the best way to minimize the damaging effects of such an event was to enhance public awareness around safety measures that must be taken.

National Center for Geophysics Administrator Alexander Sirsok outlined the history of seismic activity in Lebanon. “Lebanon is a high mountain with a vastly inclined slope diving into the Mediterranean and interrupted by the Yammouneh Fault which makes it a geological exception in its region,” he explained.

Sirsok said that the geomorphologic phenomenon is evidence of the highly active tectonic reaction in the region.

“It is quite normal for earthquakes to occur in such geomorphologic regions,” Sirsok said, adding that tsunamis are also common in the Mediterranean Basin, recalling the latest tsunami which accompanied the 2003 Boumerdes earthquake in Algeria. “Inadequate detailing of reinforcements, building adjacency, and the lack of quality, control, and construction supervision are all problems of the non-engineered buildings,” said Dr. Mohammad Harajli, who explained the means to mitigate seismic hazards in Lebanon. Harajli said designing buildings with seismic resistibility only adds the cost by “2-5 percent of the total cost.

The secretary general of the NCSR, Moeen Hamzeh, said that scientific research is at the core of knowledge and that Lebanese research around the activity of seismic fault activity meets with international standards.

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