Report on Momotombo (Nicaragua) — November 1985
Scientific Event Alert Network Bulletin, vol. 10, no. 11 (November 1985)
Managing Editor: Lindsay McClelland
Momotombo (Nicaragua) Fumarole temperatures during 1985
Please cite this report as:
Global Volcanism Program, 1985. Report on Momotombo (Nicaragua). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 10:11. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.SEAN198511-344090.
12.422°N, 86.54°W; summit elev. 1297 m
All times are local (unless otherwise noted)
On 30 May Momotombo was monitored with three sensitive portable seismographs. Three microearthquakes were recorded, one of which was detected by all three instruments, and was located at 12.455°N, 86.547°W at 1.27 km depth. Fumarole temperatures remained high (table 2), but were slightly lower than the 895°C measured in August 1984.
Table 2. Fumarole temperatures at Momotombo, January-October 1985. Courtesy of INETER.
Further Reference. Menyailov, I.A., Nikitina, L.P., Shapar, V.N., and Pilipenko, V.P., 1986, Temperature increase and chemical change of fumarolic gases at Momotombo volcano, Nicaragua, in 1982-1985: Are these indicators of a possible eruption?: JGR, v. 91, no. B12, p. 12199-12214.
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.