Report on San Cristobal (Nicaragua) — 17 August-23 August 2011
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 17 August-23 August 2011
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2011. Report on San Cristobal (Nicaragua) (Sennert, S, ed.). Weekly Volcanic Activity Report, 17 August-23 August 2011. Smithsonian Institution and US Geological Survey.
12.702°N, 87.004°W; summit elev. 1745 m
All times are local (unless otherwise noted)
The Washington VAAC reported that on 21 August emissions of gas and light ash from San Cristóbal were possibly detected in satellite imagery drifting 35 km WNW. Ash was not detected in subsequent images.
Geological Summary. 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.