Report on Cerro Negro (Nicaragua) — 14 January-20 January 2004
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 14 January-20 January 2004
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2004. Report on Cerro Negro (Nicaragua). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 14 January-20 January 2004. Smithsonian Institution and US Geological Survey.
12.506°N, 86.702°W; summit elev. 728 m
All times are local (unless otherwise noted)
According to INETER, an unusually large amount of seismic tremor occurred at Cerro Negro from December 2003 to at least mid January. The tremor had variable intensity, but was too small to be felt by the population near the volcano. During visits to Cerro Negro on 6 and 10 January, scientists did not observe any surficial changes or measure a temperature increase at fumaroles in comparison to previous months. INETER reported that the alert level may be increased from no alert to Green (the lowest alert level) if the amplitude of the tremor increases, or if there is an increase in other precursory activity.
Geologic Background. Nicaragua's youngest volcano, Cerro Negro, was created following an eruption that began in April 1850 about 2 km NW of the summit of Las Pilas volcano. It is the largest, southernmost, and most recent of a group of four youthful cinder cones constructed along a NNW-SSE-trending line in the central Marrabios Range. Strombolian-to-subplinian eruptions at intervals of a few years to several decades have constructed a roughly 250-m-high basaltic cone and an associated lava field constrained by topography to extend primarily NE and SW. Cone and crater morphology have varied significantly during its short eruptive history. Although it lies in a relatively unpopulated area, occasional heavy ashfalls have damaged crops and buildings.