A detailed account is given of the fault geometry and segment structure of the East Anatolian Fault Zone as a whole based on mapping of active faults, supported by available seismological and palaeoseismological data. We divide the East Anatolian Fault into two main strands: southern and northern. The main southern strand is c. 580 km long between Karlıova and Antakya, and connects with the Dead Sea Fault Zone and the Cyprus Arc via the Amik triple junction. The northern strand, termed the Sürgü–Misis Fault system, is c. 350 km long and connects with the Kyrenia–Misis Fault Zone beneath the Gulf of İskenderun. We infer that slip partitioning between the main and northern strands of the East Anatolian Fault accommodates 2/3 and 1/3 of the slip rate of the lateral motion between the Arabian and Anatolian plates, respectively in the Çelikhan–Adana–Antakya region. Taking account of the time elapsed from the latest events on the East Anatolian Fault, we suggest that the Pazarcık and Amanos segments have the potential to produce destructive earthquakes in the near future.Supplementary material:The data and interpretations given here are supported by five additional annotated field photographs and two tables of factual data, these are available at www.geolsoc.org.uk/SUP18568

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SUMMARY The east and west rupture directions of the 1943 and 1944 earthquakes on the North Anatolian Fault (NAF) are hypothesized to represent, respectively, long term preferred propagation directions on the corresponding sections of the NAF. Fault sections with preferred rupture direction are expected to have an asymmetric damage structure with respect to the slipping zone. To test the above hypothesis, we study geological and geomorphologic manifestations of structural asymmetry with respect to the active trace of the NAF along the 1943 and 1944 sections. The following fault zone elements are mapped: gouge fabric in the cm scale, fault core structure in a metre scale, and secondary faults and fault rocks in tens of metres scale. Mapping results at three sites on the 1943 rupture and one site on the 1944 rupture are consistent with accumulation of more rock damage on the south side of the 1943 section and on the north side of the 1944 section. Erosion patterns adjacent to the fault that are not correlated with the distribution of intrinsic and extrinsic erosion‐controlling variables (e.g. rock type) are interpreted as morphologic responses to the damage content of rocks and its impact on rock erodibility. The valleys of 11 rivers are parallel to the studied fault sections. About 75 per cent of the total river valleys length along the 1943 rupture is on the south side of the fault, and about 89 per cent of the total river valleys length along the 1944 rupture is on the north side of the fault. Morphometric analysis of watersheds in two correlative terrains displaced along the 1944 rupture section shows that stream erosion is considerably more intense in the terrain north of the fault, with drainage density values almost double in the north compare to the south. Badland topography at two sites along the 1943 rupture section is substantially more developed at the ∼100 m scale on the south side of fault. Our observations along the 1943–1944 rupture sections, including various types of signals that span a large range of scales, are systematically compatible with an opposite sense of damage asymmetry between the two fault sections. These observations are consistent with opposite preferred direction of ruptures for the two sections, similar to the propagation directions of the two recent earthquakes. If those rupture directions are dictated by the velocity structure at depth, we infer that the south side of the 1943 rupture has faster seismic velocity at seismogenic depth than the north side, and that the sense of velocity contrast is reversed along the 1944 rupture zone.

The main purpose of the present study is to investigate the possible application of decision tree in landslide susceptibility assessment. The study area having a surface area of 174.8 km 2 locates at the northern coast of the Sea of Marmara and western part of Istanbul metropolitan area. When applying data mining and extracting decision tree, geological formations, altitude, slope, plan curvature, profile curvature, heat load and stream power index parameters are taken into consideration as landslide conditioning factors. Using the predicted values, the landslide susceptibility map of the study area is produced. The AUC value of the produced landslide susceptibility map has been obtained as 89.6%. According to the results of the AUC evaluation, the produced map has exhibited a good enough performance.

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