The Enriquillo–Plantain Garden Fault crosses the southern arm of Hispaniola, running through southern Haiti and continuing into Jamaica. It is one of two major strike-slip systems that carry the motion between the Caribbean and North American plates across the island.
It is a left-lateral strike-slip fault slipping at roughly 7 millimetres per year, and it had been seismically quiet for centuries before 2010, silently building strain. The nearby Septentrional Fault to the north shares the plate-boundary load, making the region as a whole highly earthquake-prone.
On 12 January 2010 a magnitude 7.0 earthquake struck near Port-au-Prince, killing an estimated 100,000 to 300,000 people in one of the deadliest disasters in modern history. Studies later showed that unmapped blind thrust faults, not just the main Enriquillo trace, contributed to the rupture.