Source fault of 19 August 1966 Varto earthquake and its' mechanism: New field data, Eastern Turkey

19 August 1966 Varto earthquake (Ms = 6.8; Io = IX) was sourced from Varto Fault Zone (VFZ) that caused 2529 deaths in the Varto region. Just after the occurrence of the event, some researchers have different ideas related to the source fault and mechanism of the earthquake. The Varto Fault Zone is a major NW-SE trending tectonic feature in Eastern Turkey. New geological mapping and description of structures have been used to constrain the geometry, surface deformations and geological history of the fault zone. According to this extensive research, the VFZ consists of left-lateral strike-slip faults with minor amount of reverse component and has been divided into three fault segments Varto, Leylekdağ and Çayçatı regarding as geological and morphological characteristics. Hence, palaeostress configurations of the segments are reliable with the regional ∼N-S compression direction. Lastly, the Varto segment northern branch of VFZ has been defined as the source of 19 August 1966 Varto earthquake.