The 1839 Martinique earthquake occurred on the morning of January 11 with an estimated magnitude of 7.8 Ms , the largest in the Lesser Antilles since 1690.

[4] A plausible explanation for this is the slow rate of convergence resulting in the megathrust becoming seismically devoid of activity for hundreds to thousands of years before rupturing in great quakes.

[5] A similar effect was seen prior to the 2004 Sumatra-Andaman earthquake, and in Japan's Nankai Trough and the Cascadia subduction zone.

At the present moment, the Lesser Antilles subduction zone has been determined to be locked and has the potential to generate an earthquake of Mw 8.95 to 9.58.

A seismic swarm was reported in the Valley of Desolation on Dominica in 1841; a similar observation made in 1843 after the Mw  8.5 Guadeloupe earthquake.

[6] The morning of January 11 in Martinique was disrupted by three instances of violent shaking which varied in duration from 30 seconds to two minutes.

About 300 to 4,000 people died from the earthquake; the death toll varied because officials had not counted the number of slaves killed to avoid compensation requests by their owners.