Report on San Miguel (El Salvador) — December 1976

Natural Science Event Bulletin, vol. 1, no. 15 (December 1976)
Managing Editor: David Squires.

San Miguel (El Salvador) Explosive eruption began on 2 December; ashfall damages crops

Please cite this report as:

Global Volcanism Program, 1976. Report on San Miguel (El Salvador). In: Squires, D (ed.), Natural Science Event Bulletin, 1:15. Smithsonian Institution.

Volcano Profile |  Complete Bulletin

San Miguel

El Salvador

13.434°N, 88.269°W; summit elev. 2130 m

All times are local (unless otherwise noted)

An explosive eruption of San Miguel was reported to have begun during the morning of 2 December. "Smoke", loud noises, and a sulfur smell were reported from the nearby town of San Miguel. By 9 December, the eruption cloud was visible from a considerable distance and ashfalls had caused some crop damage. A few persons were evacuated. Although "fire" was reported by the press, only a white cloud was seen by Richard Stoiber during a 9 December overflight. The last activity at San Miguel was the eruption of more than 75,000 m3 of ash beginning 30 March 1970.

Further Reference. Martinez, M.A., 1977, The eruption of 2 December, 1976 of San Miguel Volcano, Republic of El Salvador, Central America: Centro de Investigaciones Geotécnicas, San Salvador, 4 p.

Geologic Background. The symmetrical cone of San Miguel volcano, one of the most active in El Salvador, rises from near sea level to form one of the country's most prominent landmarks. The unvegetated summit rises above slopes draped with coffee plantations. A broad, deep crater complex that has been frequently modified by historical eruptions (recorded since the early 16th century) caps the truncated summit, also known locally as Chaparrastique. Radial fissures on the flanks of the basaltic-andesitic volcano have fed a series of historical lava flows, including several erupted during the 17th-19th centuries that reached beyond the base of the volcano on the N, NE, and SE sides. The SE-flank flows are the largest and form broad, sparsely vegetated lava fields crossed by highways and a railroad skirting the base of the volcano. The location of flank vents has migrated higher on the edifice during historical time, and the most recent activity has consisted of minor ash eruptions from the summit crater.

Information Contacts: AFP; Sercano Radio Network; R. Stoiber, Dartmouth College.