Volcanic tremor has eased but remains elevated at San Cristobal volcano in Nicaragua. Over 15 explosions were recorded at the volcano on December 26, 2012. Ash columns reach up to 500 meters high, slightly affecting volcano surrounding towns of Tonala, Morazán, Puerto Corinto and Chichigalpa, but without causing any damage.
Yellow alert was issued for the Department of Chinandega. Officials began the precautionary evacuation of some 300 families in the province of Chinandega (northwest) after new ash emissions started at San Cristóbal volcano, following an impressive increase in seismic activity. Some 1,500 farmers living on the slopes of the San Cristobal volcano refused to leave, despite being ordered to evacuate as the volcano spewed gas, sand and ash.
The San Cristóbal volcanic complex, 100 kilometers northwest of Managua, consists of five principal volcanic edifices. The symmetrical youngest cone, San Cristóbal (also known as El Viejo) is the highest peak of the Maribios Range, and is capped by a 500 x 600 meter wide crater. El Chonco, with several flank lava domes, is located 4 kilometers to the west of San Cristóbal; it and the eroded Moyotepe volcano, 4 kilometers to the northeast of San Cristóbal. Volcan Casita, containing an elongated summit crater, lies immediately east of San Cristóbal and was the site of a catastrophic landslide and lahar in 1998. La Pelona caldera is located at the eastern end of the San Cristóbal 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 Maribios Range volcanoes.
Sources: SINAPRED, INETER, EarthquakeReport, Global Volcanism Program, USGS/CVO
Featured image credit: Tomas Stargardter/The Nicaragua Dispatch