A disaster waiting to happen - why a huge earthquake near Istanbul seems inevitable

Nervous residents of one of Europe's largest cities face devastation within 30 years
by Ian Traynor in Istanbul
The Guardian, Saturday 9 December 2006

From the top of Turkey's tallest building, the panorama over Istanbul is stunning. The huge city sprawls and crawls over a thousand hills and ravines. The Bosphorus, separating Europe from Asia, threads north to the Black Sea. To the south, beyond the domes and minarets of the old city, the turquoise waters of the Sea of Marmara push west towards the Aegean. It's all laid out before you.

Draped in large letters across four floors of glass, steel, and stone, the bank that owns the 180-metre-high (590ft) building brags: "We are here forever."

It's a brave statement towering over a city that straddles one of the most active seismic faultlines on the globe. A few miles away beneath the Marmara Sea, the North Anatolian fault line is stirring, virtually certain to rupture within a generation at the latest and bring much of Istanbul tumbling down.

"It's not a problem, totally safe. They did their homework when they built this. This can take 8 points on the Richter scale or even more," said a man brandishing a machine gun at the gates to the bank tower.

Built in the heart of a bustling business quarter not likely to risk its fortunes on the sand and mud that are the foundations for the homes of the city's millions of poor, the tower probably is secured against natural disaster.

Switch on your television set, however, and a very different message hits you. In a highly effective ad, the word Istanbul appears in capital letters made of stone across the screen. As a magnitude counter below clocks up the decimal points, the word cracks and crumbles into dust. A voice warns: "Like it or lump it, there is going to be a big destructive earthquake in Istanbul."

The ad is selling steel-girded flats and houses ostensibly guaranteed to cope with anything the North Anatolian fault can throw at them. In the past month, the company has sold more than 60 flats and cannot keep up with demand.

"Maybe the advert's a bit scary. But we're dealing in facts," said Cuneyt Kilic, deputy director of the building firm. "We're just reminding people. You can't ignore this. All the experts say that a seriously big earthquake in Istanbul will definitely happen."

It is not a question of if but when. Every year under the sea, the southern slab of the fault pushes up from the Arabian peninsula, shifting the northern plate 2.5cm (one inch) towards Greece, a very fast rate of rupture.

Predictions

"It's inevitable, a certainty," said Professor Okan Tuysuz, director of the Eurasia Institute of Earth Sciences at the city's Technical University. "We know the scale. We know the place. We just don't know exactly when, but there's a 65% probability that Istanbul will be hit by a 7.6 earthquake by 2030. That's a very high probability."

This prediction is supported by a torrent of research in recent years that has highlighted the vulnerability of this city, which is one of Europe's biggest, and the challenges of being ready for such a natural disaster. With a population of up to 15 million, growing at an estimated 400,000 a year, and with 1.6m buildings, the effect of the gloom-mongering is to engender mass anxiety about life choices: where to live, how to afford it, how to get organised.

"I'm living in a safe area, very strong, earthquake-proof," said a successful middle-class professional in his 30s. "But I'm paying a very high rent. It's a simple equation here. The rents are high where the earth is strong."

Prof Tuysuz said: "The European side of Istanbul is built on soft rock, the north and the Asian side sits on hard old rock. That's why the rich have their villas in the Bosphorus area [in the north]."

Istanbul is a famously gloomy place, and psychologists say quake-phobia is compounding that mood.

"Many people are fatalistic, leaving everything to destiny. It's a way of ignoring reality and trying to cope with the anxiety," said Ibrahim Eke, a psychologist who spent three years counselling victims of the Izmit quake, which struck 60 miles east of Istanbul in 1999. "Others are active, organising street committees to stop bad car parking that could block exits from buildings, nailing furniture to walls and floors, organising fire precautions."

Since the fifth century, Istanbul has suffered serious quake damage 12 times, most recently at the end of the 19th century. More ominously, since 1939 there have been seven earthquakes with a magnitude of more than 7 points, all on the Anatolian fault and all marching westward from eastern Turkey in a linear progression to the gates of Istanbul.

Until 1999 the little that was known about the fault had come from geological surveying related to oil and gas prospecting and was quite misleading, according to the scientists.

All that changed with the Izmit earthquake. This and a second tremor three months later left almost 20,000 dead and 600,000 homeless. It also triggered an intense bout of geological investigations. The US Geological Survey, Italian, French, and Japanese experts, Turkish institutes and Swiss Re, a reinsurance company, all intensified their studies.

The research found that the problem was not, as previously believed, a series of small, separate faults under the Sea of Marmara, but a single 1,000-mile faultline running east to west. Each time a major rupture occurs on the faultline, it "transfers stress" further along the line, making a subsequent earthquake more likely.

"The results clearly indicate that the probability for a major earthquake hitting Istanbul in the near future is far greater than previously anticipated," reported Swiss Re.

It is not possible to predict precisely when an earthquake will strike. But more refined techniques are being used to produce more accurate probability predictions. A year after the 1999 earthquake, the US Geological Survey calculated there was a 62% chance of a major Istanbul earthquake within 30 years. In 2004, Tom Parsons of the survey team reported that the probability had risen to as high as 70%.

Istanbul is far from unique. San Francisco, Los Angeles and Japan are equally exposed to risk. But California and Japan are two of the wealthiest spots on the planet, built, structured, and organised to withstand the enormous jolt.

The World Bank is pouring hundreds of millions into Istanbul's quake readiness measures. The city authorities have tightened building regulations and there are calls to demolish tens of thousands of buildings. "The city is trying its best. But there's still an awful lot of illegal building going on," said Mr Kilic of the firm building the quake-proof housing.

"About 65% of buildings in Istanbul don't meet the rules and the city is growing too fast for anyone to be able to keep up. Things have improved, but not quickly enough to cope with the problem," said Prof Tuysuz.

Worst scenario

At his Earth Sciences Institute, Prof Tuysuz has ranked the city into five zones and is using computer models to develop scenarios for the impact of a 7.4-7.6 earthquake. At worst, he said, a 7.6 quake in the Sea of Marmara could hit 40% of the city, affecting up to 5 million people. A "mini-tsunami" up to seven metres high is also feared from the Sea of Marmara. Others talk of "only" 10,000 buildings being destroyed.

Mr Eke, the psychologist, said the most optimistic scenario was that a big earthquake would leave a minimum of 10% of the inhabitants gravely traumatised, meaning 1.5 million people.

Far to the west of the city in the district of Avcilar directly overlooking the Sea of Marmara, blocks of flats are emptying and For Rent signs are sprouting.

"There used to be rich people here," said Cetin Subasi, a waterfront tailor. "But anybody with money's moved out and poor people have moved in. They say this is the danger zone. I don't know. I've lived here 20 years. Maybe they're right or maybe they're wrong."

Backstory
Istanbul's long history as the capital of two empires before becoming the biggest city in modern Turkey means there is a wealth of historical data on earthquakes. Scientists have combed the records going back 1,500 years, establishing that the city has suffered "heavy damage" from 12 tremors The North Anatolian fault, one of the most active seismic zones in the world, runs within a few miles of the city under the Sea of Marmara. Since the disastrous Erzincan earthquake in December 1939 in eastern Turkey, there have been six earthquakes along the fault with a magnitude greater than seven points, all progressing from east to west. The most recent, in 1999, was less than 60 miles east of Istanbul.