Report on Santa Ana (El Salvador) — December 1980
Scientific Event Alert Network Bulletin, vol. 5, no. 12 (December 1980)
Managing Editor: David Squires.
Santa Ana (El Salvador) Plume from inner crater fumaroles
Please cite this report as:
Global Volcanism Program, 1980. Report on Santa Ana (El Salvador) (Squires, D., ed.). Scientific Event Alert Network Bulletin, 5:12. Smithsonian Institution.
13.853°N, 89.63°W; summit elev. 2381 m
All times are local (unless otherwise noted)
Observations were made during a flight over the country. A moderate plume rose from a bank of fumaroles on the SE wall of the inner crater, very similar to its appearance in November 1978.
Geologic Background. Santa Ana, El Salvador's highest volcano, is a massive, dominantly andesitic-to-trachyandesitic stratovolcano that rises immediately W of Coatepeque caldera. Collapse of Santa Ana (also known as Ilamatepec) during the late Pleistocene produced a voluminous debris avalanche that swept into the Pacific Ocean, forming the Acajutla Peninsula. Reconstruction of the volcano subsequently filled most of the collapse scarp. The broad summit is cut by several crescentic craters, and a series of parasitic vents and cones have formed along a 20-km-long fissure system that extends from near the town of Chalchuapa NNW of the volcano to the San Marcelino and Cerro la Olla cinder cones on the SE flank. Historical activity, largely consisting of small-to-moderate explosive eruptions from both summit and flank vents, has been documented since the 16th century. The San Marcelino cinder cone on the SE flank produced a lava flow in 1722 that traveled 13 km E.
Information Contacts: R. Stoiber, S. Williams, R. Naslund, L. Malinconico, and M. Conrad, Dartmouth College.