AN earthquake measuring 5.2 on the Richter scale hit northwestern Turkey today, Turkey's earthquake monitoring centre said. The quake was felt in Istanbul. The quake's epicentre was in the province of Balikesir, across the Marmara Sea from Istanbul, Turkey's largest city. There were no reports of injuries or damage. Turkey, which lies on a major fault line, has suffered devastating earthquakes in the past and in August 1999 nearly 18,000 people were killed in a quake, also in the northwest. Some people in Istanbul felt todays' quake. Residents are jumpy as scientists have predicted a major earthquake is likely to hit in the next 30 years.