Concepción, Nicaragua

By ExploreNow Editor, on January 15th, 2012

Volcano Type:     Stratovolcano
Volcano Status:   Historical
Last Known Eruption:    2010
Summit Elevation:    1700? m    5,577 feet
Latitude:    11.538°N    11°32’16″N
Longitude:    85.622°W    85°37’21″W

Volcán Concepción is one of Nicaragua’s highest and most active volcanoes. The symmetrical basaltic-to-dacitic stratovolcano forms the NW half of the dumbbell-shaped island of Ometepe in Lake Nicaragua and is connected to neighboring Madera volcano by a narrow isthmus. A steep-walled summit crater is 250 m deep and has a higher western rim. N-S-trending fractures on the flanks of the volcano have produced chains of spatter cones, cinder cones, lava domes, and maars located on the NW, NE, SE, and southern sides extending in some cases down to Lake Nicaragua. Concepción was constructed above a basement of lake sediments, and the modern cone grew above a largely buried caldera, a small remnant of which forms a break in slope about halfway up the north flank. Frequent explosive eruptions during the past half century have increased the height of the summit significantly above that shown on current topographic maps and have kept the upper part of the volcano unvegetated.

Concepción Volcano at sunset

Concepción volcano and its twin neighbour Madera form the island of Ometepe in Lake Nicaragua. It is an almost perfect steep cone built on a thick sequence of sediments beneath Lake Nicaragua. It has been described as having a “clay foot”. The volcano is experiencing gravity induced spreading do to a weak clay base. The volcano rises 1600 m above Lake Nicaragua. Prevailing trade winds send tephra deposits west of the cone of Concepcion, while lavas mainly extends east. Tephra deposits are 50 m think at Moyogalpa, 8 km west of the crater. There is almost no tephra on the coastal plain north and south of the volcano.

Concepción Volcano at sunset

The summit of Concepcion volcano has increased in height by 100 m in recent times due to eruptive activity. Most of the visible upper part of the cone was built between 1883 and 1977. Forest is scarce in the volcano, and is not well developed compared to neighbouring Maderas volcano. There is a striking lack of faulting at Concepcion volcano compared to surrounding areas.