Maca Volcano | John Seach



45.10 S, 73.20 W
summit elevation 2960 m

Maca is a large stratovolcano located in southernmost part of the South Andean Volcanic Zone, Chile.

The central volcanoes (Maca, Cay and Hudson) lie the direction of Andean volcanic arc. Maca volcano is located 15 km from Cay volcano, and 230 km east of the Chile trench.

Maca volcano occurs at the NW end of a, NW–SE-trending volcanic ridge, 10 km long and 3 km wide. The ridge has an elevation of 1500–1700 m. The volcano summit contains a steep-sided depression opening toward the SSE, which probably represents a flank failure.

Five flank cones, aligned along a 15 km NE–SW fissure, occur down to sea level, particularly on the SW flank of the volcano. Lava flows have originated from some of the cones, and are well preserved with little vegetation cover. The southernmost cones were formed underwater, and contain hyaloclastite.

2007 Earthquakes
A seismic swarm occurred at Aisén Fjord 20 km south of the volcano, with 7000 earthquakes recorded between 22nd January and early May 2007. The largest earthquake was magnitude 6.2 on 23rd April 2007. The earthquake sequence was considered responsible for the eruption of Chaiten volcano 250 km further north in May 2008.

Further reading
D'Orazio, Massimo, et al. "The Quaternary calc-alkaline volcanism of the Patagonian Andes close to the Chile triple junction: geochemistry and petrogenesis of volcanic rocks from the Cay and Maca volcanoes (~ 45 S, Chile)." Journal of South American Earth Sciences 16.4 (2003): 219-242.

Maca Volcano Eruptions

410 AD ± 50 years