Strike-slip fault in the context of "2006 Yogyakarta earthquake"

A transform fault or transform boundary, is a fault along a plate boundary where the motion is predominantly horizontal. It ends abruptly where it connects to another plate boundary, either another transform, a spreading ridge, or a subduction zone. A transform fault is a special case of a strike-slip fault that also forms a plate boundary.

Most such faults are found in oceanic crust, where they accommodate the lateral offset between segments of divergent boundaries, forming a zigzag pattern. This results from oblique seafloor spreading where the direction of motion is not perpendicular to the trend of the overall divergent boundary. A smaller number of such faults are found on land, although these are generally better-known, such as the San Andreas Fault and North Anatolian Fault.

The Anatolian plate is a continental tectonic plate lying under Asiatic part of Turkey, known as Anatolia. Most of the country of Turkey is located on the Anatolian plate. The plate is separated from the Eurasian plate and the Arabian plate by the North Anatolian Fault and the East Anatolian Fault respectively. According to the American Museum of Natural History, the Anatolian transform fault system is "probably the most active in the world".

Most significant earthquakes in the region have historically occurred along the northern fault, such as the 1939 Erzincan earthquake. The northern edge is a transform boundary with the Eurasian plate, forming the North Anatolian Fault zone (NAFZ). The East Anatolian Fault, a left lateral transform fault, forms a boundary with the Arabian plate. The devastating 2023 Turkey–Syria earthquakes occurred along the active East Anatolian Fault at a strike-slip fault where the Arabian plate is sliding past the Anatolian plate horizontally.

The Walton fault zone is a major active left lateral (sinistral) strike-slip fault, forming part of the southern boundary to the Cayman Trough. It extends from the Mid-Cayman Rise spreading center in the west to Jamaica in the east. It has a total length of about 360 km and is formed of several sub-parallel strands. Together with the Enriquillo-Plantain Garden fault zone it forms the southern boundary of the Gonâve Microplate. It is associated with only moderate earthquakes with magnitudes of less than 6.

In geology, transpression is a type of strike-slip deformation that deviates from simple shear because of a simultaneous component of shortening perpendicular to the fault plane. This movement ends up resulting in oblique shear. It is generally very unlikely that a deforming body will experience "pure" shortening or "pure" strike-slip. The relative amounts of shortening and strike-slip can be expressed in the convergence angle alpha which ranges from zero (ideal strike-slip) to 90 degrees (ideal convergence). During shortening, unless material is lost, transpression produces vertical thickening in the crust. Transpression that occurs on a regional scale along plate boundaries is characterized by oblique convergence. More locally, transpression occurs within restraining bends in strike-slip fault zones.

Transtension is the state in which a rock mass or area of the Earth's crust experiences both extensive and transtensive shear. As such, transtensional regions are characterised by both extensional structures (normal faults, grabens) and wrench structures (strike-slip faults). In general, many tectonic regimes that were previously defined as simple strike-slip shear zones are actually transtensional. It is unlikely that a deforming body will experience 'pure' extension or 'pure' strike-slip.

Transtensional shear zones are characterized by the co-existence of different structures, related to both strike-slip shear and extension. End member structures include pure strike-slip faults and purely extensional ("normal") dip-slip faults. Faults which have components of both (termed 'oblique' slip faults) are abundant.