The North Anatolian fault in Turkey is known as a “sister” of California’s San Andreas fault because they are the same age, the same length, and their slip rate, or average annual movement, down through the centuries has been about the same.
But in the last century, the North Anatolian fault has been more active, with 12 major quakes to the San Andreas’ two, and its magnitude-7.4 Aug. 17, 1999, quake was far more costly in terms of human life than anything California has experienced.
There were more than 17,000 confirmed fatalities in the 1999 quake, 20,000 remain unaccounted for, and more than 1 million people fled their homes for extended periods.
Tonight at 10 on the Learning Channel, an hourlong documentary titled “Great Quakes” records what happened in the 1999 quake and examines the threat to Istanbul should the westerly progression of recent Anatolian quakes continue.
Ross Stein, a leading earthquake scientist with the U.S. Geological Survey in Menlo Park, Calif., is featured in the program directed by Julio Moline from Vantage Point Productions.
Stein, who has spent six weeks in Turkey on several study trips since the 1999 quake, collaborated with Japanese and Turkish scientists in a study that resulted in an estimate last year that there is a 62% probability, plus or minus 15%, that a magnitude 7 or larger quake will strike within 30 miles of Istanbul in the next 30 years.
This is similar to 30-year quake-probability estimates scientists have made for the San Francisco Bay Area, although the projection there is for a smaller quake and the area considered is larger. The reaction in Turkey, however, has echoed the Bay Area’s: lukewarm.
Richard Andrews, former director of the California State Office of Emergency Services, who has been doing post-earthquake work in Turkey for the World Bank, observes that some Turkish officials did not appreciate the estimate by Stein and the others, although Andrews says they take the quake threat seriously.
Denial is a major problem in quake-prone areas, with potential victims often ignoring the danger until something happens.
But tonight’s production is careful to express the limits of scientific knowledge on quakes. It abjures the sensationalism that all too often marks such shows.
Istanbul largely rests on bedrock, and the nearest known major fault is 10 miles away. The North Anatolian fault breaks up into strands in the Sea of Marmara, southeast of the city. Yet the 1999 quake, centered near Izmit, 60 miles east of Istanbul, still did considerable damage inside the city in parts of it subject to liquefaction.
“Great Quakes” is pointed in its assessment that huge population growth in Istanbul in recent years has often been accompanied by shoddy apartment construction. It notes that newer buildings, short of reinforcing, with little steel and poor-quality cement, actually fared more poorly than older buildings in the 1999 quake.
In one segment, a construction contractor is shown being arrested for alleged negligence in apartment construction. But since the program was filmed, he has been released without trial.
In California, construction quality has been better, building collapses comparatively few, and the death toll has been held down. Still, the Turkish experience can serve in some respects as a warning here.
* “Great Quakes” can be seen tonight at 10 on the Learning Channel. The network has rated it TV-PG (may be unsuitable for young children).