M 7.6 - 209 km SSW of George Town, Cayman Islands

M 7.6 - 209 km SSW of George Town, Cayman Islands

The February 8, 2025, M7.6 earthquake southwest of the Cayman Islands occurred as the result of strike slip faulting in the shallow crust near the boundary between the North America and Caribbean plates. Focal mechanism solutions indicate that rupture occurred on a steeply dipping structure striking either west-northwest (right-lateral), or west-southwest (left-lateral). At the location of this earthquake, the North America plate moves to the west-southwest with respect to the Caribbean plate at a rate of approximately ~20 mm/yr. Local to the February 8, 2025 earthquake, this motion is predominantly accommodated along the Swan Islands transform fault, a left-lateral structure. The location, depth and focal mechanism solution of today’s earthquake are consistent with rupture occurring along this plate boundary structure, or on a nearby and closely related fault.

While commonly plotted as points on maps, earthquakes of this size are more appropriately described as slip over a larger fault area. Strike-slip-faulting events of the size of the February 8, 2025, earthquake are typically about 140x20 km (length x width).

Large earthquakes at this location of the plate boundary are not unexpected. Ten M6 or larger earthquakes have occurred within 250 km the February 8, 2025 earthquake over the preceding century. Notably, on January 10, 2018, an M7.5 earthquake occurred nearby with a similar mechanism. This 2018 earthquake caused some damage and a small tsunami. Luckily, the remote location of these earthquakes limits the potential for significant damage due to shaking.