An earthquake measuring 3.5 on the Richter scale shook Turkey’s economic heartland on Thursday, October 4th.

The Turkish Earthquake Research Association and the Turkish Disaster Management Authority both estimate that the epicenter of the earthquake was 2 to 3.5 kilometers deep in the Marmara Sea, south of Istanbul.

This is the third time in the last few days that an earthquake has occurred in Istanbul. An earthquake measuring 2.8 on the Richter scale and a magnitude 2.8 on the Richter scale shook the city, which holds a third of Turkey’s GDP.

Turkish media have reported that there were no reports of financial damage and earthquake casualties.