The 1999 Düzce earthquake occurred on 12 November at with a moment magnitude of 7.2 and a maximum Mercalli intensity of IX (Violent), causing damage and at least 845 fatalities in Düzce, Turkey. The epicenter was approximately to the east of the extremely destructive 1999 İzmit earthquake that happened nearly three months earlier. Both strike-slip earthquakes were caused by movement on the North Anatolian Fault. Tectonic setting The western and central parts of Turkey lie on the eastern part of the Anatolian Plate, which is currently being forced to the west by the continuing northward movement of the Arabian Plate. In northern Turkey, this westward motion is taken up by a major zone of dextral (right-lateral) strike-slip, the North Anatolian Fault. The 1999 Düzce event is the most recent in a sequence of large earthquakes that have affected the North Anatolian Fault, starting towards the eastern end with the 1939 Erzincan earthquake, then propagating towards the west with events in 1942, 1943, 1944, 1951, 1957, 1967 and finally the 1999 İzmit event. At its western end the North Anatolian Fault splits into two main segments, with the northern of these giving rise to the 1999 earthquakes. Earthquake The earthquake had an estimated magnitude in the range 7.1–7.2 on the moment magnitude scale. The International Seismological Centre gives a magnitude of 7.16±0.1 for this event in their catalogue. The maximum measured intensity was IX at a seismometer about 4 km from the epicentre, with a peak ground acceleration of 147.80%g and a peak ground velocity of 113.02 cm/sec. Ground rupture A surface rupture of 40 km was identified in the field along the Düzce Fault, part of the northern splay of the North Anatolian Fault. This was extended by an additional 15 km at the eastern end using SPOT imagery. The maximum identified lateral displacement was 5 m, with an average displacement of 3 m. At the western end of the fault, there was a maximum 3.5 m of vertical displacement. Rupture propagation Analysis of seismometer records suggests that the rupture propagated towards the east faster than the S-wave velocity (supershear) and to the west slower than the S-wave velocity. Supershear rupture propagation is characteristic of strike-slip earthquakes, particularly on fault segments that are relatively simple and planar in geometry. Damage Düzce and surrounding areas had already been quite badly affected by the İzmit earthquake a few months earlier, so that