Report on Momotombo (Nicaragua) — May 1985
Scientific Event Alert Network Bulletin, vol. 10, no. 5 (May 1985)
Managing Editor: Lindsay McClelland
Momotombo (Nicaragua) Continued high fumarole temperatures
Please cite this report as:
Global Volcanism Program, 1985. Report on Momotombo (Nicaragua). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 10:5. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.SEAN198505-344090.
12.422°N, 86.54°W; summit elev. 1297 m
All times are local (unless otherwise noted)
Summit fumarole temperatures have remained high, with small fluctuations probably related to seasonal rainfall variations. The maximum temperature in 1984 was 895°C in August; the same fumarole had a temperature of 875°C when measured in 1985.
Geologic Background. Momotombo is a young, 1297-m-high stratovolcano that rises prominently above the NW shore of Lake Managua, forming one of Nicaragua's most familiar landmarks. Momotombo began growing about 4500 years ago at the SE end of the Marrabios Range and consists of a somma from an older edifice that is surmounted by a symmetrical younger cone with a 150 x 250 m wide summit crater. Young lava flows from Momotombo have flowed down the NW flank into the 4-km-wide Monte Galán caldera. The youthful cone of Momotombito forms a 391-m-high island offshore in Lake Managua. Momotombo has a long record of strombolian eruptions, punctuated by occasional larger explosive activity. The latest eruption, in 1905, produced a lava flow that traveled from the summit to the lower NE base. A small black plume was seen above the crater after an April 10, 1996 earthquake, but later observations noted no significant changes in the crater. A major geothermal field is located on the southern flank of the volcano.
Information Contacts: D. Fajardo B., INETER.