Professor Erdik says İstanbul is a prime location for earthquakes

“We can say that İstanbul has the highest probability of an earthquake among the world's mega cities,” he told Today's Zaman during a Monday Talk interview.

However, he said there is no way of knowing when an earthquake may take place.

“It may take place in 10 seconds, or it may not take place in 50 years. The only thing we can talk about is probabilities,” he added.

Ten years ago today, the Marmara region in northwestern Turkey began shaking at 3:02 a.m. in a magnitude 7.4 earthquake that lasted for 45 seconds. According to official records, 18,373 people died, 48,901 people were injured and hundreds of thousands of people became homeless. Experts say there will be another earthquake and it may well happen in İstanbul, where the population is estimated to be close to 15 million. The Aug. 17 earthquake increased tectonic stress on the Marmara fault in İstanbul.

For Monday Talk, Professor Erdik elaborated on earthquake probability studies, the importance of earthquake preparedness and what is being done in İstanbul in that regard.

Is it really possible to predict when an earthquake is likely to happen?

It is very hard to do that. There have been earthquakes in the world for 100 million years. But we have been doing probability analyses for old countries like Turkey and China for the last 2,000 years and for the United States for the last 200 years. So we are trying to understand an old phenomenon through a limited number of observations. Still, today's research will probably help societies in 500 years to understand earthquake prediction. However, there are some probability studies regarding a possible earthquake in İstanbul.

Would you elaborate on the results of such studies?

The research points to a 68 percent probability of an earthquake in İstanbul in the next 30 years. This approximately means a 2 percent chance a year. We prefer yearly estimates rather than 30-year probabilities because such probabilities encourage people to count down. This probability of 60 percent in 30 years was given in 2002 for İstanbul, and people started to count down.

Mustafa Erdik, award-winning professor of engineering Currently the director of Kandilli Observatory and Earthquake Research Institute at İstanbul's Boğaziçi University, Erdik is a professor of earthquake engineering. In 1999, he received the UN Sasakawa Award for Disaster Reduction, and in 2004, he received the NATO Summit Science Prize. He has worked with a number of international organizations including UNESCO and the UNDP on earthquake engineering problems. He is also a member of the editorial board of several professional journals and serves on the executive board of a few professional societies. He has written five books. His current research interest is earthquake hazard and risk assessment.

Do you consider this 2 percent a high probability?

Yes, only San Francisco and Tokyo have a 2 percent yearly probability of an earthquake among the other [major] cities in the world. In İstanbul, a large earthquake depends on the activity of only one fault line. In San Francisco, there are at least seven fault lines. In Tokyo, there are three main fault lines, and one of them is under the sea.

Can you predict the time of an earthquake?

The public is interested in knowing this, but we cannot tell. An earthquake may take place in 10 seconds, or it may not take place in 50 years. The only thing we can talk about is probabilities. And as I said, the chance of a large earthquake in İstanbul is 2 percent a year. This is shared only by Tokyo and San Francisco. We can say that İstanbul has the highest probability of an earthquake among the world's mega cities. In İzmir, the yearly probability of a large earthquake is 0.4 percent. … So there is eight times less probability in İzmir than İstanbul. But that does not tell you the imminence of an earthquake. Tomorrow, we can have an earthquake in İzmir, but we may not have one in İstanbul.

Where does the high probability of an earthquake in İstanbul come from?

It comes from the past sequence of earthquakes. The statistics from the last 2,000 years indicate that. The average recurrence period is about 250 years. However, there have been periods where there were no earthquakes for 350 years, and there have been periods where there were two earthquakes in 100 years. And the 1999 earthquake in Kocaeli has increased tectonic stress on the main Marmara fault in İstanbul. When we take all of these into consideration, the probability of an earthquake in İstanbul amounts to 2 percent a year.

‘İstanbul has unique earthquake master plan’

This high probability brings us to another area which is earthquake preparedness. For this purpose, you prepared a master plan.

Four universities prepared an earthquake master plan. It was prepared for the İstanbul Metropolitan Municipality in 2005-2006 by Middle East Technical University [ODTÜ], Boğaziçi University, İstanbul Technical University and Yıldız Technical University. There are not many cities in the world with an earthquake master plan. The only other city with such a plan might be Los Angeles in the United States.

Would you talk about the content of the master plan?

The master plan is a voluminous study on risk assessment of buildings and retrofitting, reconstruction applications, legislation, financial resources, education and training, social activities and fundamentals and procedures of disaster and risk management in İstanbul. The main guiding principle has been that while no natural disaster can be prevented from happening, the incorporation of well-formulated planning and technical countermeasures will mitigate damage and losses significantly. The plan is a transparent document readily accessible to the public. Any institution can have a look at the master plan and draw up its own disaster management plan. Recently, an institution has been formed in Ankara, the Disaster and Emergency Management Directorate directly under the Prime Ministry, to also deal with earthquake preparedness activities. This will be one of the unique agencies in the world dealing with earthquake preparedness.

İstanbul's cultural heritage likely to suffer huge losses “There are two things we cannot replace following a possible earthquake in İstanbul. One is the loss of human life, and the other is İstanbul's cultural heritage. The last time İstanbul's cultural sites saw an earthquake was 250 years ago. Some of them have been repaired, and some of them have been rebuilt. Some reconstructions are in quite earthquake vulnerable areas. For example, Fatih Mosque has been built on an area where there all of the prior churches collapsed in earthquakes. And in the last large-magnitude earthquake in 1999 -- which was 120 kilometers away from İstanbul -- Fatih Mosque was seriously damaged. Several historical buildings are likely to collapse in İstanbul in addition to museums. Also artifacts that are displayed in the museums are likely to be damaged. There should be a big campaign to save these for future generations. There is no lack of money to do this, but there is a lack of capacity.”

Are there no earthquake preparedness plans in the other countries of the world?

It is unique to İstanbul. There were studies done in Bucharest, Romania, under the radical regime of Nicolae Ceauşescu. But they couldn't succeed. Similar studies were done in Los Angeles for unreinforced masonry structures. They had a city ordinance in trying to fix such structures so they wouldn't be damaged. But there was not much success either. Independent of the regime, it is a difficult process to do that, and İstanbul is trying to undertake this difficult task.

What is the most important element of such an undertaking?

The most important elements are sociology and psychology, the trust of people in the administration and the government. It is not a technical issue.

And there is a legal aspect, new building codes and regulations.

New codes relate to new buildings. The new buildings in İstanbul are in much better shape than the older structures. But to your surprise, the real reason behind this is not the new rules and regulations but the betterment of the economy. As the economy started to get better and inflation dropped starting in 2000, big corporations have had better access to capital, and what you see in İstanbul is not as much individual construction as in the past but the development of complexes. The companies that build these complexes have their own strict codes and controls. In other words, the construction business has been industrialized in Turkey.

‘20 percent of schools, 2 percent of  hospitals and bridges retrofitted’

What is the situation regarding reinforcement of older buildings in İstanbul?

About 20-30 percent of schools have already been retrofitted or are in the process of being retrofitted.

Isn’t this a low percentage? Is it so hard to inspect and reinforce school buildings?

It is not, but we are talking about hundreds of buildings. İstanbul is a big city. Inspecting is not difficult, and most of them have been inspected. What is difficult is finding financing to reinforce them.

How about the hospitals?

Only about 1 or 2 percent of hospitals have been retrofitted. It is more difficult to retrofit hospitals since you don't want to interrupt the operation of hospitals. But the success story in İstanbul is about bridges and viaducts. Almost all bridges and viaducts in İstanbul have been inspected. The vulnerable ones have been retrofitted. That includes suspension bridges, all the connecting viaducts, such as the Ortaköy Viaduct. Currently, there is work under way on the Mecidiyeköy Viaduct. There is a new technology used -- rubber base isolators -- to isolate ground vibrations before they reach the deck of the bridge. The Haliç Bridge was also retrofitted. So in a possible earthquake in İstanbul, the transportation system is not likely to be affected.

But you have to take people to hospitals.

Of course, but I am trying to say that earthquake management is not just about retrofitting buildings. And when we talk about old buildings, we talk about buildings built prior to the year 2000. That's a huge problem.

‘Expected deaths from earthquake comparable to deaths from smoking’

The details are scary when we learn that İstanbul is a prime earthquake area and most buildings are not earthquake resistant. Is this a discouraging factor for people planning to settle in İstanbul?

It shouldn't be because we are all exposed to other risks. The number of casualties that we have in Turkey due to traffic accidents is about 6,000 a year. About 100,000 people die in Turkey due to diseases related to cigarette smoking. If you take this number and see how many people die in İstanbul due to cigarette smoking -- İstanbul houses about one-fifth of Turkey's population -- you will see that about 20,000 will die yearly in İstanbul because of diseases related to smoking.

How many people are expected to die in İstanbul due to a large earthquake?

New computations show that at about 30,000. So expected deaths from an earthquake in İstanbul are comparable to deaths from cigarette smoking and traffic accidents. But it is not only about deaths. Returning to normalcy after an earthquake is a big problem, and that may take some time. In Italy's L'Aquila earthquake in April 2009, the death rate of about three people in 1,000 is the same as in a possible earthquake in İstanbul. The collapse rate is also about the same. People are not abandoning L'Aquila, so why should people do that in İstanbul?

About returning to normalcy, are there studies related to that?

There are no such studies. But there should be some. The economy and the stock market should be operational as soon as they could be. People should have access to work. There should be planning for new construction. There should also be planning to dump the earthquake rubble. Returning to normalcy is a big issue for a financial center like İstanbul. Electricity might be off; gas might be off. Companies might not be able to pay their taxes. There are so many micro-enterprises in İstanbul, and they are likely to be hugely affected by an earthquake. Just at those micro-enterprises, we estimate that about 200,000 will lose their jobs. Who is going to take care of that? There should be planning for how life can be revitalized after an earthquake.