What is the world's highest volcano?
Nevados Ojos del Salado volcano on the Chile/Argentina border is the world's highest volcano above sea level, but it rises only about 2,000 m above its base. The broad summit of Mauna Loa shield volcano is 2,700 m lower than Nevados Ojos del Salado, but it's height above base is almost 10 times that of the Andean volcano.
|Volcano||Country||Elevation above sea level|
|Nevados Ojos del Salado||Chile-Argentina||6,879 m (22,563 feet)|
|Llullaillaco||Chile-Argentina||6,739 m (22,104 feet)|
|Tipas||Argentina||6,658 m (21,838 feet)|
|Nevado de Incahuasi||Chile-Argentina||6,638 m (21,773 feet)|
|Coropuna||Peru||6,377 m (20,917 feet)|
|El Condor||Argentina||6,373 m (20,903 feet)|
|Parinacota||Chile-Bolivia||6,336 m (20,782 feet)|
|Chimborazo||Ecuador||6,310 m (20,697 feet)|
|Pular||Chile||6,233 m (20,444 feet)|
|El Solo||Chile-Argentina||6,205 m (20,352 feet)|
The summits of the world's ten highest Holocene volcanoes (above) are all constructed above the structural highs of the Andes mountains. The highest volcano with documented historical eruptions is Llullaillaco, which had three in the 2nd half of the 19th century. Active fumaroles, however, mark the summit crater of Nevados Ojos del Salado, 267 km to the south and 148 m higher than Llullaillaco. The youthful nature of Nevados Ojos del Salado suggests that its lack of historical eruptions stems only from its remote location, and it is rightfully the world's highest volcano. The only higher mountain in the Americas, Argentina's Aconcagua at 6962 m, was listed as active by Darwin during the voyage of the Beagle, but Chilean colleagues tell us that the mountain is not a volcano and its height results from imbricate thrust faulting.
A very different picture emerges when considering the height of volcanic edifices themselves, as measured from their constructional bases rather than sea level. Massive oceanic shield volcanoes of Hawaii, such as Mauna Loa, rise as much as 9,000 m above the sea floor. These volcanoes are by far the world's largest by volume, dwarfing the continental-margin stratovolcanoes of the Andes. Furthermore, the weight of the countless overlapping lava flows forming these shield volcanoes substantially depresses the oceanic crust beneath them. Geophysical evidence indicates that the full height of Mauna Loa above its base is an astounding 19 kilometers, more than twice the height of Mount Everest above sea level.
Unfortunately, determining the true base of a volcano is often difficult, and we do not have accurate height-above-base data for enough volcanoes to provide a meaningful list.
Global Volcanism Program, 2013. Volcanoes of the World, v. 4.7.0. Venzke, E (ed.). Smithsonian Institution. Downloaded 25 Jun 2018. https://doi.org/10.5479/si.GVP.VOTW4-2013