Momotombo volcano
© Jaime Incer
Momotombo volcano in Nicaragua reported first eruptions in the last 110 years on the morning (local time) of December 1, 2015. The eruptions produced steam and ash plumes rising up to 1 km (3 281 feet).

Four small explosions occurred at the volcano at 07:49, 08:17, 08:42 and 08:55 am (local time), Volcano Discovery reported. The last of the eruptions was the largest and sent a plume of ash and steam high above the crater.

The communities of El Papalonal and in the vicinity of the Momotombo geothermal plant situated SW of the volcano summit reported light ash fall. A team of volcanologists from the Nicaraguan Institute of Territorial Studies (INETER) surveyed the area and took samples of ash and gasses.

This is the first time the volcano showed the signs of eruptive activity since 1905, and only 16 eruptions have been recorded since 1524, most of which have been small explosions of phreatic nature. The only two larger eruptions were observed in 1605 and 1609 when large bombs and blocks were expelled to the distances of approximately 6 km (19 685 feet), in the area of the nowadays abandoned town of León Viejo.

According to the scientists the volcano explosions has not been triggered by the increased activity of the nearby Telica volcano over the last few weeks.

Geological summary

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.