Scenarios for a future earthquake in Istanbul were on the agenda yesterday on the ninth anniversary of a devastating quake that hit the Marmara region.
“The likelihood of an earthquake in the Marmara region is 60 percent. We expect it to occur within the next 30 years,” said professor Gülay Altay from the Kandilli Observatory and Earthquake Research Institute at Boğaziçi University. The high likelihood an earthquake in Istanbul has caused residents of the city to fear another such disaster.
Urban regeneration is the only way to make the city of Istanbul as ready as possible for a prospective earthquake, according to Greater Istanbul Municipality's emergency preparedness plan. The municipality, which collaborated with Japanese experts in creating its earthquake master plan, has allocated YTL 366.7 million for earthquake risk management.
The municipality also announced last week the results of its Earthquake Risk Analysis project jointly undertaken with the Japan International Cooperation Agency, or JICA, in 2003. The analysis includes four different earthquake scenarios for Istanbul.
Not rescue but prevention
The municipality will give priority to taking necessary precautions as quickly as possible to minimize damage and the death toll in a possible earthquake, rather than solely focusing on how to rescue victims trapped under debris. In order to determine what kind of an action plan is needed and what strategies should be followed, a scientific report has been created on the earthquake resistance of Istanbul as part of the Municipality-JICA joint study.
Four Japanese and 10 Turkish scientists, and 15 Japanese, and eight Turkish engineers worked collaboratively to prepare the report, which was based on four different scenarios. Predicted magnitudes in each of these scenarios are 6.9, 7.4, 7.5 and 7.7 on the Richter scale. The report also includes predicted damage in each neighborhood of Istanbul. The estimated number of households is about 3 million with the city's nighttime population at 9 million. The scenarios indicate that a 7.5 or 7.7 earthquake will have a death toll between 70,000 and 90,000 people.
The municipality has prepared what it calls its “Earthquake Master Plan” to minimize damage in case of an earthquake. According to the plan, the urban regeneration project launched in the Zeytinburnu district will be broadened to cover other districts and neighborhoods of Istanbul. Experts have completed a ground survey and a seismic micro-regioning project in Zeytinburnu.
More than 16,000 buildings have been scientifically examined and those that should be demolished have been selected. A total of 2,295 buildings have been labeled risky. All legal procedures for the urban regeneration project have been fulfilled. Again, the master plan says engineers have begun examining all buildings in Fatih and Küçükçekmece districts. Ground surveys and micro-regioning of these two districts have been completed.
Helicopters, seismic-watch stations
The municipality has spent approximately YTL 4.4 million so far on scientific studies to prevent a possible earthquake. It has also spent YTL 18 million for geological maps. Some earthquake danger maps, soil liquefaction maps, ground enlargement and tsunami maps have been prepared. Drilling work was carried out over 135,000 square meters.
On the other hand, the Emergency Coordination Center has purchased three new helicopters to be used in rescue activity and traffic control. The center employed 1,852 persons in 2004, but the personnel size has been increased to 4,982.
The number of firefighting centers has also been increased from 38 to 70, and the number of firefighting vehicles has been increased from 292 to 519. A logistical support center has been established. Seismic stations to watch micro-earthquake activities around Istanbul have been established at 14 locations. Finally, daily changes in the physical and chemical composition of natural spring waters and radon gas are recorded at 16 hydraulic stations installed along existing fault lines in the Marmara region.
Predicted figuresMagnitude: 7.5 or 7.7
Death toll: 70,000-90,000
Seriously wounded: 135,000
Families to become homeless: 500,000-600,000
Seriously damaged buildings: 50,000-60,000
Water leakage spots: 1,000-2,000
Leakage at 30,000 natural service regulators
Breakage of 3 percent of electrical wires
140 million tons of debris
Rescue operation for 1 million people
$40 billion financial loss