Dona Juana

Geography & Climate

Dona Juana is located in Colombia, within the Northern Andean Volcanic Arc of the broader South America Volcanic Regions. Situated at 1.50° N, 76.94° W in the Northern Hemisphere, the volcano lies within a tropical climate zone. Standing at 4,137 meters above sea level, Dona Juana towers above the alpine zone, where vegetation gives way to bare rock, snow, and ice for much of the year. The high elevation means the upper slopes experience significantly colder temperatures than surrounding lowlands. The volcanic landform is characterized as a composite, which describes the physical shape and structure of the volcanic edifice as observed from the surface.

Geological Context

Dona Juana sits in a subduction zone, where one tectonic plate dives beneath another, creating intense heat and pressure that generates magma. Subduction zones are responsible for many of the world's most explosive volcanoes and deadliest eruptions. For communities in Colombia near Dona Juana, this tectonic setting means the volcano is capable of producing powerful explosive eruptions, pyroclastic flows, and lahars that can threaten populated areas within tens of kilometers of the summit. The dominant rock type is andesite / basaltic andesite, a dark, fine-grained volcanic rock that forms from rapidly cooling, low-viscosity lava. Basaltic eruptions tend to be less explosive and produce fluid lava flows that can travel long distances. While less immediately dangerous than explosive eruptions, basaltic lava flows can destroy structures and infrastructure in their path, and volcanic gases released during these eruptions can affect air quality over a wide area.

Eruption History Summary

Dona Juana has 2 recorded eruptions in the geological database, spanning from 2550 BCE to 1897 CE. The most powerful recorded event was a cataclysmic eruption with ash columns reaching the stratosphere in 1897 CE, reaching VEI 4 on the Volcanic Explosivity Index. Notable eruptions include 1897 CE (VEI 4), 2550 BCE (VEI 4). These eruptions span roughly 4,447 years of volcanic history.

Significance

With a maximum recorded VEI of 4, Dona Juana has demonstrated the capacity for significant explosive eruptions that can impact regional aviation, agriculture, and communities tens of kilometers from the summit. VEI 4 eruptions produce ash columns reaching 15-25 kilometers into the atmosphere.

GVP Reference Summary

The forested Doña Juana stratovolcano contains two calderas, breached to the NE and SW. The summit of the andesitic-dacitic volcano is comprised of a series of post-caldera lava domes. The older caldera, open to the NE, formed during the mid-Holocene, accompanied by voluminous pyroclastic flows. The younger caldera contains the active central cone. The only historical activity took place during a long-term eruption from 1897-1906, when growth of a summit lava dome was accompanied by major pyroclastic flows.

— Smithsonian Institution, Global Volcanism Program