Report on San Cristobal (Nicaragua) — April 1976
Natural Science Event Bulletin, vol. 1, no. 7 (April 1976)
Managing Editor: David Squires.
San Cristobal (Nicaragua) Significant increase in gas output
Please cite this report as:
Global Volcanism Program, 1976. Report on San Cristobal (Nicaragua) (Squires, D., ed.). Natural Science Event Bulletin, 1:7. Smithsonian Institution. https://doi.org/10.5479/si.GVP.NSEB197604-344020.
12.702°N, 87.004°W; summit elev. 1745 m
All times are local (unless otherwise noted)
It is believed that the activity during April remained static. The gas output was about five times more than it was before the two small ash eruptions in March, and this involves a sulfur output of thousands of tons/day.
Geologic Background. The San Cristóbal volcanic complex, consisting of five principal volcanic edifices, forms the NW end of the Marrabios Range. The symmetrical 1745-m-high youngest cone, named San Cristóbal (also known as El Viejo), is Nicaragua's highest volcano and is capped by a 500 x 600 m wide crater. El Chonco, with several flank lava domes, is located 4 km W of San Cristóbal; it and the eroded Moyotepe volcano, 4 km NE of San Cristóbal, are of Pleistocene age. Volcán Casita, containing an elongated summit crater, lies immediately east of San Cristóbal and was the site of a catastrophic landslide and lahar in 1998. The Plio-Pleistocene La Pelona caldera is located at the eastern end of the complex. Historical eruptions from San Cristóbal, consisting of small-to-moderate explosive activity, have been reported since the 16th century. Some other 16th-century eruptions attributed to Casita volcano are uncertain and may pertain to other Marrabios Range volcanoes.
Information Contacts: R. Hazlett, Dartmouth College.