Yemen

Yemen's seismicity arises from its position at the junction of three actively rifting tectonic systems: the Red Sea rift, the Gulf of Aden rift, and the East African Rift, all meeting at the Afar Triple Junction — one of the world's most extraordinary tectonic features. Yemen straddles the passive rift shoulder of both the Red Sea and the Gulf of Aden spreading centres, meaning the country is being pulled apart in multiple directions as these young ocean basins widen. The main Red Sea rift axis runs along the central Red Sea, but the rift-bounding [[fault]] systems extend under the Yemeni coastal mountains (the Hijaz and Asir escarpments). The Gulf of Aden to the south is a faster-spreading ocean basin where the Aden Ridge is creating new oceanic crust at approximately 20 millimetres per year. Yemen's highest seismicity is concentrated in the far west, in the Afar Triangle region shared with Djibouti and Eritrea, and along the Gulf of Aden coast.

Yemen's seismic history includes numerous events associated with the rifting systems. The Dhamar earthquake of December 13, 1982 (magnitude 6.0) killed 2,800 people and injured 1,500 in the central highlands — a devastating event that exposed the vulnerability of traditional stone and earthen construction. The 2001 Azal Province earthquake (magnitude 5.3) killed 10 people. The volcanic island of Jabal al-Tair in the Red Sea erupted in 2007 after an earthquake sequence, killing two people. The Gulf of Aden has produced several moderate offshore earthquakes with felt effects on Yemen's southern coast. The Socotra Archipelago, a remote island group of Yemen in the Arabian Sea, also experiences seismicity from the Gulf of Aden rift system.

The deeper tectonic context of Yemen's seismicity reflects its position on the western shoulder of the Gulf of Aden rift and the eastern shoulder of the Red Sea rift. The rifting apart of the Arabian Peninsula from Africa began approximately 30–35 million years ago, and Yemen's rugged western highlands represent the uplifted rift shoulder — terrain elevated by the thermal expansion and isostatic adjustment associated with lithospheric thinning. The Marib-Shabwa Basin and other sedimentary basins in central Yemen developed as pull-apart structures in the early rift phase. The [[epicenter]] distribution of Yemeni earthquakes shows clear clustering along the Red Sea coast, the Gulf of Aden coast, and the Afar Depression to the west. The interior plateau of central Yemen and the Hadramaut region to the east are more stable geologically, though they are not immune to shaking from coastal and offshore events.