Azores triple junction

This triple junction is located along the Mid-Atlantic Ridge (MAR) amidst the Azores islands, nearly due west of the Strait of Gibraltar.

The spreading rate along the MAR does not change abruptly at the ATJ, instead decreasing from 22.9±0.1 mm/yr at 40°N to 19.8±0.2 mm/yr at 38°N.

This means the ATJ is not a simple triple junction where three tectonic plates meet at a point.

The transitional range of spreading rates instead indicates the presence of a microplate, commonly referred to as the Azores Microplate, although the observed behaviour can also be explained in terms of a diffuse boundary.

The microplate moves about 2 mm/yr east-northeast along its Nubian (African plate) boundary.