TURKEY'S SECOND devastating earthquake in four months has underlined the dangers facing the capital Istanbul, but offered few dramatic new lessons about structures and seismic activity in the region, British engineers said this week.
'It would be panic-mongering to talk of a new threat to the city,' said one UKbased earthquake specialist. 'Earthquakes are unpredictable. We know the risk of a severe event in the next ten years is already high.'
Last week's devastation centred on the town of Duzce to the south east of Istanbul. An area about 40km across was hit, with a death toll of 400 and rising, and at least 700 buildings destroyed. Strong tremors in the capital caused damage to buildings.
A section of the E5 highway which runs into Istanbul collapsed on one side.
Chai Chiew, head of the consultant Owen Williams' risk office in Istanbul, told NCE that the latest destruction in Duzce followed a similar pattern to August's huge earthquake centred in Izmit (NCE 2 September).
'But this is a hilly area and there is less soft ground liquefaction and more structural damage,' said Chiew. Buildings that suffered were poorly engi-neered or often built to old standards.
Turkish TV this week quoted local seismic experts as suggesting that the 7.2 Richter event will increase the risk of ground stresses building up in faults near the capital, he added.
The same North Anatolian fault that moved at Izmit was involved. A branch of this fault heads west into the Sea of Marmara and now poses greater dan-ger for Istanbul, it is suggested.