The 1509 Constantinople earthquake or historically ('Minor Judgment Day') occurred in the Sea of Marmara on 10 September 1509 at about 10 p.m. The earthquake had an estimated magnitude of on the surface wave magnitude scale. A tsunami and forty-five days of aftershocks followed the earthquake. The death toll of this earthquake is poorly known, with estimates in the range of 1,000 to 13,000. Background The Sea of Marmara is a pull-apart basin formed at a releasing bend in the North Anatolian Fault, a right-lateral strike-slip fault. This local zone of extension occurs where this transform boundary between the Anatolian Plate and the Eurasian Plate steps northwards to the west of Izmit from the Izmit Fault to the Ganos Fault. The pattern of faults within the Sea of Marmara basin is complex but near Istanbul there is a single main fault segment with a sharp bend. To the west, the fault trends west–east and is pure strike-slip in type. To the east, the fault is NW-SE trending and shows evidence of both normal and strike-slip motion. Movement on this fault, which bounds the Çınarcık Basin, was the most likely cause of the 1509 event. Damage The area of significant damage (greater than VII (Very strong)) extended from Çorlu in the west to Izmit in the east. Galata and Büyükçekmece also suffered severe damage. In Constantinople 109 mosques were utterly destroyed, while most of those left standing suffered damage to their minarets. While 1070 homes collapsed, 49 towers along the Walls of Constantinople also collapsed or were damaged. The newly built Bayezid II Mosque was badly damaged; the main dome was destroyed and a minaret collapsed. The Fatih Mosque suffered damage to its four great columns and the dome was split. The quake also damaged the Rumeli Fortress, Anadolu Fortress, the Yoros Castle in Anadolu Kavağı, and the Maiden's Tower. The Grand Mosque of Hagia Sophia survived almost unscathed, although a minaret collapsed. Inside the mosque, the plaster that had been used to cover up the Byzantine mosaics inside the dome fell off, revealing the Christian images. The number of dead and injured is hard to estimate, with different sources giving accounts varying from 1,000 to 13,000. It is believed that some members of the Ottoman dynasty died in this earthquake. Aftershocks continued for 45 days after the earthquake, and people were unable to return to their homes for two months.