1974 Lesser Antilles earthquake

The 1974 Lesser Antilles earthquake occurred at 05:50:58 local time on October 8 with a moment magnitude of 6.9 and a maximum Mercalli intensity of VIII (Severe). Four people were injured in what the United States' National Geophysical Data Center called a moderately destructive event.

1974 Lesser Antilles earthquake

Show map of Caribbean Show map of Antigua and Barbuda
UTC time	1974-10-08 09:50:58
ISC event	736214
USGS-ANSS	ComCat
Local date	October 8, 1974 (1974-10-08)
Local time	05:50:58
Magnitude	6.9 Mw[1]
Depth	35.2 km (22 mi)[1]
Epicenter	17.3°N 62.0°W / 17.3; -62.0[1]
Type	Normal[2]
Total damage	Moderate[3]
Max. intensity	MMI VIII (Severe)[3]
Casualties	4 injured[4]

Tectonic setting

See also: Volcanic arc

While the northern and southern boundary of the Caribbean plate are complex and diffuse, with zones of seismicity stretching several hundred kilometers across, the eastern boundary is that of the Lesser Antilles subduction zone. This 850 km (530 mi) long subduction zone lacks a uniform curve and has an average dip of 50–60°. The largest known earthquake on the plate interface was a M7.5–8.0 event in 1843, but it did not generate a large tsunami. In opposition, the three largest events between 1950 and 1978 were intraplate normal faulting events.^[5]

See also

• Lesser Antilles
• List of earthquakes in 1974
• List of earthquakes in the Caribbean