Antisana Volcano - John Seach



0.48 S, 78.14 W
summit elevation 5753 m

Antisana is a large glacier covered stratovolcano located 50 km SE Quito. It is located in the Northern Volcanic Zone of the Andes.

The volcano is located in Anisana Ecological Reserve which covers an area of 296,000 acres. Antisana volcano is part of the Condor Bioreserve.

Antisana volcano is situated in the Eastern Cordillera, at the latitude where the volcanic chain is widest. It is one of the largest volcanoes in Ecuador. Antisana is a Quaternary stratovolcano built in at least two phases. The southeastern portion is the old volcano, which covers two-thirds of the volcano. It is composed of numerous volcanic breccia deposits, lava and pyroclastic flows. This area of the volcano has been reshaped by glacial action. Activity at the old volcano finished with two explosive eruptions which formed the eastern and southern calderas.

The northwest flank of the Antisana, comprising one-third of the volcano is a younger, regular cone-shaped edifice. This region contains numerous lava flows which were erupted from the summit.

The region of the North Volcanic Zone around Antisana volcano has a striking lack of intermediate depth seismicity. Lava at Antisana is highly porphyritic (often >40% modal phenocryst content).

1801-02 Eruption
Two lava flows erupted from satellite fissures 15 km west of the base of the cone. These are the Antisanilla and Potrerillos lava flows (10 and 15 km long).

Antisana Volcano Eruptions

1801-02, 1728?, 1590