Shallow earthquakes beneath Dominica may be related to magma movement. Dominican Earthquakes of a magnitude large enough to be recorded at seismographs on the other islands in the Lesser Antilles occur at a rate of one or two a year. More significant are the locally-felt swarms of small magnitude earthquakes. Tens to hundreds of earthquakes occurred in such swarms in 1765, 1841, 1849, 1893 and October 1937 to April 1938. Seismographs were first installed in Dominica in the 1950s and since then, instrumentally recorded swarms with felt shocks have occurred in 1967, 1971, 1974, 1976, 1986 and 1998 in the south of the island. In 2003 one such swarm yielding over 1000 earthquakes was recorded in the North of Dominica and was felt in all the villages around Mt. Au Disables volcano.
Historical Seismic Activity
1693: An earthquake, estimated intensity IV (4) centered on or near Dominica.
1765: Earthquake and Gas". 150 shocks felt in February and March and a few more until June: "more violent than any previously felt". Activity somewhere on Dominica.
1816: 15 August, severe shocks, estimated intensity V (5), centered on or near Dominica. 1838: June, several shocks maximum intensity V, centered on or near Dominica.
1843: 8 February, strong tectonic earthquake Mw=8.3 north of Dominica, felt with intensity VIII (8) in Roseau, intensity IX (9) elsewhere in Dominica and on Guadeloupe, Antigua, Montserrat, Nevis, and St. Kitts. A relatively small earthquake in December was felt only in Roseau and several more small earthquakes were felt in 1844-1845, 1847 and 1849.
1879: 10 September, earthquake beneath or near Dominica, maximum intensity V.
1967: A swarm of 66 shallow earthquakes between 19 and 21 June.