Azores–Gibraltar transform fault
The Azores–Gibraltar transform fault, also called a fault zone and a fracture zone, is a major seismic zone in the eastern Atlantic Ocean between the Azores and the Strait of Gibraltar. It is the product of the complex interaction between the African, Eurasian, and Iberian plates. Since the beginning of seismological records in the 1700's, the AGFZ has produced the following large-magnitude earthquakes and accompanying tsunamis: 1755 Lisbon, 1761 Lisbon, 1816 North Atlantic, 1941 Gloria Fault earthquake, 1969 Horseshoe and 1975.
Geologic setting
Forming the Atlantic segment of the boundary between the African and Eurasian plates, the AGFZ is largely dominated by compressional forces between these converging plates, but it is subject to a dynamic tectonic regime that also involves extension and transform faulting. The oceanic lithosphere in the area is directly related to the opening of the North Atlantic Ocean and is one of the oldest preserved on Earth.The western end of the AGFZ, the Azores triple junction on the Mid-Atlantic Ridge, is where the North American, African, and Eurasian plates meet. Spreading in the MAR is faster south of the AGFZ than north of it, which results in a transcurrent movement along the AGFZ at about. The eastern segment of the fault is complex and characterised by a series of seamounts and ridges separating the Tores and Horseshoe abyssal plains. The active compressional deformation in this segment is an extremely rare example of compression between two oceanic lithospheres.