Report on San Cristobal (Nicaragua) — 26 December-1 January 2013
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 26 December-1 January 2013
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2012. Report on San Cristobal (Nicaragua). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 26 December-1 January 2013. Smithsonian Institution and US Geological Survey.
12.702°N, 87.004°W; summit elev. 1745 m
All times are local (unless otherwise noted)
INETER reported that on 26 December four explosions at San Cristóbal produced ash plumes that were observed in satellite imagery drifting W and reaching the Pacific Ocean. Ashfall was reported in areas within 5-6 km of the volcano. The next day explosions produced ash plumes that rose 200 m above the crater. On 28 December gas-and-ash plumes drifted NW, W, and SW, reaching the Pacific Ocean and the coast of El Salvador. Explosions were detected until 1100. Sulfur dioxide emissions continued and drifted W and SW; the emissions decreased the next 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.