Anguilla

Anguilla is a British Overseas Territory in the northern Lesser Antilles, situated at the junction of the outer carbonate arc and the active volcanic island arc where the North American Plate subducts westward beneath the Caribbean Plate. The island lies immediately north of Saint Martin, approximately 200 kilometres east-northeast of Puerto Rico. Unlike neighbours in the active volcanic arc, Anguilla is built on older Eocene limestone and subdued volcanic hills, placing it on the non-volcanic outer arc of the Lesser Antilles system. The primary seismic source is the [[subduction-zone]] interface to the east-northeast, where convergence occurs at roughly 2 centimetres per year. Secondary sources include the Anegada Passage fault zone to the west, which separates the Greater and Lesser Antilles and is capable of generating moderate to large earthquakes. Seismic hazard is considered moderate — lower than the active volcanic arc islands to the south, but elevated relative to tectonically stable continental regions.

Anguilla's earthquake history reflects proximity to active tectonic structures rather than a record of locally generated destructive events. The great 1843 Guadeloupe earthquake — estimated [[magnitude]] 8.0 — was strongly felt throughout the northern Lesser Antilles including Anguilla, damaging masonry buildings. The 1867 Virgin Islands earthquake (magnitude 7.5), centred in the Anegada Passage, generated a damaging [[tsunami]] that swept coastal communities across the northern arc; Anguilla's low-lying southern shoreline faces meaningful [[tsunami]] exposure from such events. In the instrumental era, the island has registered numerous felt events from the regional subduction system, including M5–6 arc earthquakes and a magnitude 6.3 event in November 2004 near the Virgin Islands.

Anguilla's geology records its position on the carbonate platform of the northern outer arc. The island rises only 65 metres above sea level at its highest point — one of the flattest territories in the Caribbean — reducing landslide risk but amplifying [[tsunami]] inundation potential. Earthquake monitoring is conducted by the University of the West Indies Seismic Research Centre as part of the regional network extending from Trinidad to Puerto Rico. [[tsunami]] preparedness and coastal evacuation planning are the most critical emergency management priorities for this low-lying island, given known hazards from Anegada Passage fault ruptures and Caribbean-wide subduction events.